.
Technical Specifications
_____________________________________________________________________________________________________________
Post Ebola Recovery Program (Sierra Leone)
(Ref # 96718)
Technical Specifications
For
Construction of Screening and Isolation Units (SIU) for the
Government Hospitals
(New Construction)
ANNEX B.3: TECHNICAL SEPCIFICATIONS
December 2015
1
.
Technical Specifications
_____________________________________________________________________________________________________________
TABLE OF CONTENT
SECTION 01 – PRELIMINARIES AND GENERAL GUDIELINES...…………………………….3
SECTION 02 - EARTHWORKS ………………………………………………………………..…..11
SECTION 03 - CONCRETE WORKS …….………………………………………………………..17
SECTION 04 - MASONRY ……………………...…..………………………………………….…..26
SECTION 05 – ROOFING ………………………………………………...………………………...28
SECTION 06 – WOOD WORK, DOORS AND WINDOWS………………...……………………..31
SECTION 07 – METAL WORK…….……………………………………...………...……………...37
SECTION 08 – PLUMBING INSTALLATION …………………....……………………………….40
SECTION 09 - ELECTRICAL INSTALLATION……………………........……………….………..44
SECTION 10 – INSITU FINISHES………………..…………………………………………….…..53
SECTION 11 – PAINTING ………………………………………………...………………………..55
SECTION 12 – EXERNAL WORKS…………………………..…………...………………………..59
SECTION 14 – ENVIRONMENTAL AND HEALTH & SAFETY MANAGEMENT ……….……61
2
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 01 : PRELIMINARIES AND GENERAL GUIDELINES
1.
Scope of Works
The items contained in the scope of works are indicative only. The Contractor is entirely responsible
for ascertaining the precise extent of works described in the scope of works in arriving at his price for
each item. All costs in connection with renovation and repair works must reflect all work deemed
necessary by and to the complete satisfaction of the Engineer to restore building structure, fabric and
finishing to their original installed condition or better.
2.
Abbreviations of Standards
The following abbreviations have been
used for the Standards applicable to the
Works under the Contract.
BS
CP
ASTM
ACI
-
British Standards
Code of Practice
American Society for Testing and Materials.
American Concrete Institute.
-
3.
Standards
The works have been designed to incorporate and utilize economically, goods, materials and
workmanship to various specifications which are detailed herein. Reference is commonly made to
British Standards (BS) and British Standard Codes of Practice (CP) and to the American Society for
Testing and Materials Standards (ASTM). Different National or International Standards ISO, DIN, etc.,
that correspond to the specified BS or ASTM Standard may be used provided that their requirements
are not less stringent, and provided that the Contractor presents copies of such Standards translated into
English. If any redesign of the Works is necessitated by the adoption of such alternatives the costs
incurred shall be borne by the Contractor.
Except where specifically indicated otherwise all references shall be deemed to refer to the current
standards (the latest edition or issue) as of the date of the signing of the Contract.
4.
Units of Measurement and Abbreviations
All units of weight and measurement shall be based on the Metric system of Weights and
Measurements except standard products which may be expressed in nominal units of the Imperial
System.
The metric
symbol
m
m2
m3
Kg
Tonne
Description
Abbreviation
Description
Linear Metre
Square Metre
Cubic Metre
Kilogram
1000 Kilogram
mm
cm
No
C
LS
Millimetre
Centimetre
Number
Celsius
Lump Sum
3
.
Technical Specifications
_____________________________________________________________________________________________________________
5.
Definitions
Wherever in the Contract Documents, or on the Drawings, the words "as directed", "as Described", "as
ordered", "as requested", "as required", "as permitted", or words of like import are used, it shall be
understood that the direction, description, order, request, requirements or permission of the Engineer is
intended. Similarly, the words "approved", "acceptable", "satisfactory" and words of like import shall
mean approved by, acceptable to, or satisfactory to the Engineer.
6.
Bill of Quantities
The Contractor shall price each individual item in Bill of Quantities. Rates shall be deemed to include
plant, labour, materials, allowance for wastage, transportation and overheads and profit. Rates shall also
be used in the evaluation(s) on site as appropriate.
7.
Material Specification and Sourcing
In choosing the materials and specifications to be incorporated in the Project, close consideration must
be made with regards to the:
- Availability
- Accessibility
- Durability
- Washable (for specific materials)
- Sustainability
- Energy Saving
- Environmental Friendly
All materials must meet the standards as specified within the codes of practices and specifications listed
in each section. Quality and strength test of the materials used on site must be clearly specified.
Locally sourced materials shall be deemed satisfactory for use only after all Declaration and
Certification of Origin and Conformity have been duly provided by the Contractor and authenticated
by the Supervising Engineering.
8.
Locating, Protecting, Maintaining and Diverting Services and Public Utilities
The Contractor shall ascertain the whereabouts of all existing services and public utilities such as
electrical cables, telephone lines, sewers, water supply lines. gas lines, pipes, wires, fences, etc., on the
site, both above and below ground. Service and other utilities may exist in certain locations not indicated
on drawings. Completeness or accuracy of information given on the drawings is not guaranteed. It is the
responsibility of the Contractor to ascertain their whereabouts from the concerned authorities before
commencing any works on site. The Contractor shall also obtain any re-routing requirements from the
concerned authorities and shall be responsible to carry out such works accordingly to the satisfaction of
the authorities and the Engineer.
Where diversions of services are not required in connection with the permanent works, the Contractor
shall project, uphold, maintain and keep the same in working order in their existing locations and shall
restore them to their original condition on completion to the satisfaction of the Engineer.
The Contractor shall make good, at his own expense, all damage caused to any of the services and public
utilities by him or his sub-contractors, except where the Public Authority or Private Party Owning the
same, elects to make good the damage under their own arrangements. The cost incurred in making good
the damages by the Public Authority or Private Party shall be paid to them by the Contractor on demand.
4
.
Technical Specifications
_____________________________________________________________________________________________________________
All costs in connection with the above works shall be borne by the Contractor without any extra cost to
the Client.
The Client shall not be liable for any loss or injury in connection with any of the above works.
9.
Water for the Works
The Contractor shall provide all necessary water for the works including that required for testing and
commissioning of the works including those of the sub-contractors and nominated sub-contractors,
irrespective of availability of main supply. The Contractor shall provide all temporary plumbing and
storage, pay all charges, and alter, adapt and maintain temporary works as necessary and remove and
make good on completion.
10.
Temporary Power and Lighting for the Works
The Contractor shall provide all necessary artificial lighting and power for the execution, security of the
works, protection and for the purposes of testing and commissioning of the works. including those of
the sub-contractors and nominated sub-contractors, irrespective of availability of main supply, with all
meters, temporary wiring and fittings, etc., pay all charges, and alter, adapt and maintain the temporary
work as necessary and remove and make good at completion.
11.
Safeguard of Life and Health
The Contractor shall take and apply all necessary measures for the safeguard of the life and health of
his workers, including the provision and maintenance of adequate First Aid Facilities throughout the
Contract Period.
12.
Safety and Security
It will be the sole responsibility of the Contractor to provide full and continued security and safety for
the site including all site facilities until the substantial completion certificate is issued and all the works
are completed and the Contractor has demobilized.
The Contractor shall allow for complying with any current security regulations and requirements which
may be applicable to the site. The Contractor will be deemed to have acquainted himself thoroughly
with all security regulations that may be in force at the time of submission of tender and to have allowed
in his tender for their effect upon his operations with regard to the supply of labour and materials, access
to site and project execution generally. No claim will be entertained for the Contractor’s lack of
knowledge of security regulations. The Contractor shall ensure that his workforce and staff on site
adhere strictly to cultural restrictions.
The cost of any delay resulting from the security requirements and regulations will deemed to be
included in the tender price.
Safety practice shall comply with the requirement the local/governing Municipality/Authorities.
a) Safety helmets
b) Safety shoes
c) Protective eye glass
d) Ear muffs
Contractor shall liaise with the Engineer and shall observe and ensure that all their personnel observe,
all relevant security procedures particularly those applicable to performing works in an ongoing
operating environment
Laboratories used to perform test shall be approved by the Engineer.
5
.
Technical Specifications
_____________________________________________________________________________________________________________
The Engineer reserves the right to utilize the Contractor’s control testing laboratory and equipment to
make spot tests and to check the Contractor’s testing procedures, techniques, and test results at no
additional cost to the Employer.
13.
Scaffolding
The Contractor shall provide, erect, maintain, dismantle and clear away at completion proper and
adequate scaffolding including that required for Sub -Contractors and Specialists. Putlog holes should
be made good to match the adjacent surface as the scaffolding is dismantled. The Contractor shall be
entirely responsible for all safety precautions in connection with the stability of the scaffolding and for
its entire sufficiency for the Work. Scaffolding shall be a complete system from a manufacturer
approved by the Engineer. The Contractor shall provide shop drawings and design calculations to prove
the sufficiency of the proposed system for the intended applications for the approval of the Engineer as
and when called for to do so. However approval accorded by the Engineer shall not absolve the
Contractor of any of his responsibilities or obligations.
14.
Method Statement
The Contractor shall compile and submit a detailed schedule of method statements that are to be
furnished by him and his sub-contractors including nominated sub-contractors in fulfillment of his
responsibilities as specified and required to complete the project for the approval of the Engineer. Any
modifications/comments of the Engineer shall be incorporated and resubmitted for approval. The
Engineer however shall have the right to request for method statements for non-listed items, if required,
in the interest of this project and the Contractor shall provide the same.
15.
Keeping Site Free From Rubbish
The premises and the Project site shall be maintained in a reasonably neat and orderly condition by the
Contractor and his sub-contractors and kept free from accumulations of waste materials and rubbish
during the entire construction period. The Contractor shall remove all crates, cartons and other
flammable waste materials or trash from the work areas at the end of each working day.
Floors shall be "broom-cleaned", or its equivalent, during the course of the work. Additional cleaning
of all other items which are provided as a part of the Contract, including removal of dust, dirt, stains and
finger marks from all finished wood, metal, marble or glass surfaces, shall be performed by the
Contractor as required to the approval of the Engineer, before handover of the works. The Contractor
shall be responsible for the general cleaning and maintenance of the premises and the Project site and
for the co-ordination of the clean-up work of all trades. The Contractor shall ensure that each trade shall
clean and maintain its portion of the work as required and as directed by the Engineer. If the premises
and job site are not maintained properly, the Engineer, may have any accumulations of waste materials
or trash removed and deduct such costs from payments due to the Contractor.
16.
Setting Out
The Contractor shall employ an experienced Land Surveyor to carry out all setting out and surveying
work.
Before the commencement of the Works the Contractor will be supplied with the information necessary
to establish the lines and levels of the Works. The Engineer has shown on the Drawings all the Survey
markers established but can give no warranty for their existence at the start of the Contract nor will he
accept responsibility for replacing any survey markers found to be missing. Where survey markers have
6
.
Technical Specifications
_____________________________________________________________________________________________________________
been established by the Engineer the Contractor shall check the accuracy of their position and level and
shall immediately notify the Engineer of any discrepancies.
The Contractor shall, as soon as practicable, supply the Engineer with records in approval form relating
to all reference pegs and bench marks and shall keep such records up to date by formal notice to the
Engineer.
All survey reference pegs shall be carefully preserved except where construction requires their removal
and before such removal the approval of the Engineer shall be obtained.
In order to establish the existing ground levels over the areas of the works, the Contractor shall establish
a grid over the Site and agree the levels with the Engineer. The Contractor shall prepare drawings
representing the configuration of the areas which shall be signed by the Engineer and the Contractor as
record.
The Contractor shall establish bench marks and grid lines at each floor showing exact floor elevations
and other lines and dimensional reference points as required.
17.
Shop Drawings
Provide accurately prepared, large scale and detailed shop drawings on reproducible sheets, prepared
specifically for the Project for all disciplines and as instructed by the Engineer. The shop drawings shall
show adjacent conditions and related work. Accurate field dimensions and conditions shall be shown.
Any special coordination with other trades required shall be clearly noted.
Notwithstanding any specific requirements, if at any time before the commencement or during the
progress of the work it appears to the Contractor that for the proper execution of a specific part of the
Works, shop drawings are necessary, these drawings shall be prepared by the Contractor and submitted
to the Engineer for approval. The Engineer shall have authority to order at any time and the Contractor
shall provide any number of shop drawings which, in the opinion of the Engineer are necessary for the
proper execution of a specified work. The Contractor shall not proceed with the above mentioned work
unless these shop drawings are approved by the Engineer.
All shop drawings shall be properly checked and coordinated with all connected trades/ disciplines by
the Contractor and shall be signed by a designated qualified coordination Engineer as proof of
verification and correction and submitted to the Engineer.
18.
Record Drawings
The Contractor shall maintain one complete set of drawings of all disciplines (Structural, Electrical,
Mechanical, civil, landscaping, External works etc.), at site exclusively to note all deviations/changes
and submission at the time of completion of the works. All changes/deviations and details such as levels
of foundations, routing of services, invert levels of pipes, cables, manholes, etc., the position of tees,
bends, cleanouts and other appurtenances, details of underground services encountered and any other
relevant data, locating dimensions where appropriate shall be accurately and neatly recorded on these
drawings as work proceeds. All changes noted/recorded on the drawings shall be submitted to the
Engineer for approval as and when the changes occur and are recorded.
19.
As-Built Record and Survey Drawings
The Contractor shall prepare ‘as-built’ record and survey drawings of the Works detailing all works
installed under the contract including services and all finished level surface. The drawings shall be
accompanied by maintenance manuals, service literature and lists of spare parts where applicable.
As-built record drawings, operation and maintenance manuals and any other literature required for the
efficient operation of the completed works shall be supplied by the contractor to the Engineer free of
7
.
Technical Specifications
_____________________________________________________________________________________________________________
charge. The drawings shall be on polyester film or other durable and easily reproducible medium,
approved by the Engineer.
The Contract shall not be considered as complete until the Contractor submits to the Engineer the asbuilt drawings and documentation, and obtains the Engineer’s approval.
Copies of as- built drawings and documentation shall be submitted to the Engineer before the expiry of
the Contract Period as named in the Contract and shall include one copy of each drawing and document
specifically marked for archival storage. The Certificate of Maintenance (FCC – Final Completion
Certificate) will not be signed by the Engineer until all as-built drawings and accompanying documents
and service literature are approved and a certificate has been issued by the Engineer to his effect.
20.
Identification
No later than 10 days prior to commencement on site, the Contractor shall submit to the Engineer or his
representative the names of all workers to be on the site, together with the company name (in the case
of subcontractors).
Workers are to leave the site upon completion of their work.
21.
Alternative Materials
Should the Contractor wish to offer alternative items or materials to those specified he shall supply
details of such alternatives together with details of any reduction in the Contract Price should the
alternative be allowed to be substituted for the specified items or materials. All offered alternatives shall
comply fully in all respects with the Specifications of the particular items or materials. Acceptance or
refusal of any alternatives will be entirely at the discretion of the Engineer.
If during the course of the Contract certain materials or items required for use in the Works should be
unobtainable, despite the best effort of the Contractor, the Contractor may offer for the approval of the
Engineer alternative materials or items, provided that they possess the minimum requirements of the
originally specified material.
In the event of acceptance of any alternative materials or items a suitable price reduction shall be made
in respect of any decrease in value but no price addition shall be made in respect of increase in value.
In the event of refusal of any alternative materials or items the Contractor shall not be relieved of any
of his obligations under the Contract and shall be solely liable for any delay or loss occasioned by his
failure to provide the materials or items as specified.
22.
Materials, Goods and Workmanship Generally
The whole of the goods materials and workmanship incorporated in the works shall be new and of the
best quality available and shall be to the approval of the Engineer.
Should the Engineer discover on the Works any materials other than those specified or approved, he
may order their removal from the site and for their replacements as specified. All costs incurred for such
removal and replacement, and of associated works shall be borne by the Contractor.
23.
Samples and Testing of Materials
A. Samples
Prior to ordering or delivering any materials or manufactured items to the Site, the name and address of
the supplier(s) and, where required by the Engineer, adequate samples, schedules and manufacturer's
certificates of all the materials and goods to be used in the Works shall be submitted to the Engineer for
approval at no extra cost to the Project.
8
.
Technical Specifications
_____________________________________________________________________________________________________________
In case of rejections further samples, until final approval is accorded, shall be submitted. The Contractor
shall have no claims to extra cost or time lost due to improper submissions, the resultant rejections and
the approval process.
If considered necessary and ordered by the Engineer, the samples shall be tested for compliance at the
Contractor's expense in a laboratory approved by the Engineer.
B. Testing
The Contractor shall be, at his own expense, responsible for the sampling, storage, transportation and
laboratory testing of products and materials as required in the Specification.
The Contractor shall make available on site necessary equipment for the use of the Engineer for tests to
be conducted at site.
Eg. - Slump cone with baseplate and tamping rod.
- Thermometer suitable for measuring concrete temperature.
- Magnetic flux principle instrument for non-destructive method of testing paint film thickness. - etc.,etc.
In addition, suitable experienced labor to carry out the operations in connection with the above shall be
provided by the Contractor as required by the Engineer.
The Contractor shall allow for the costs of the above in his unit rates.
24.
Construction Schedule
The Contractor shall prepare a coordinated schedule of all the works, including incorporation of the
works of his sub-contractors and nominated sub-contractors and submit the same for the approval of the
Engineer.
The schedule shall be prepared using proprietary latest software such as:
Primavera
And compressed as CPM PERT CHART and GANTT chart, showing earliest and latest start/finish
times for each activity and related periods of float.
Contractor shall prepare and submit to the Engineer, within 30 days of issue of notice to commence a
fully weighted “S” curve indicating planned construction effort and related labor and plant histograms.
“S” curve shall be updated with actual progress on weekly basis and incorporated in the Contractor’s
Weekly Report.
25.
Periodic Reports
The Contractor must present to the Engineer detailed daily/weekly reports and monthly summary report
showing the following:
(a) Labor force working during the period.
(b) Quantity and Type of materials and equipment used during the period.
(c) Quantity of works executed.
(d) Climatic conditions with special reference to any direct effect they may have on the works.
(e) Unforeseen circumstances (if any) which may hamper the progress of the Works.
(f) Graph showing the relation between the executed portions of the works and the corresponding
portions in the Work Programme.
The Contractor shall prove to the Engineer upon his request the correctness of the above mentioned
reports without having the right to use such documents to support a claim for any extra payment or
9
.
Technical Specifications
_____________________________________________________________________________________________________________
compensation whatsoever in regard or in relation to such reports. However this shall not vitiate the rights
of the Engineer to use the report as evidence to decide on any aspects connected with delays and claims.
26.
Site Progress Meetings
During the course of the Work, Site progress meetings shall be held at regular intervals, at least once
every two weeks, or at other intervals as directed by the Engineer, for the purpose of coordinating the
Contractor's Works and to ensure that full compliance with the various sequences of the Contract are
maintained. Minutes of such Site meetings will be recorded by the Engineer and copies will be
distributed to all persons concerned and full effect shall be given to all instructions contained therein.
Prior to such meetings the Contractor shall give to the Engineer's Representative details in writing of
that portion of the Works he proposes to construct during the coming two weeks with details of the plant
and methods he proposes to employ. These proposals shall be discussed at the meeting and no work
based on such proposals shall proceed without the approval of the Engineer's Representative.
The Contractor shall have no claim against the Employer for costs incurred by him in changing the
method of working or in the provision and use of other additional plant.
Agenda:
1. Review minutes of previous meetings.
2. Review of Work progress.
3. Field observations, problems, and decisions.
4. Identification of problems impeding planned progress.
5. Review of submittals schedule and status of submittals.
6. Review of off-site fabrication and delivery schedules.
7. Maintenance of progress schedule.
8. Corrective measures to regain projected schedules.
9. Planned progress during succeeding work period.
10. Coordination of projected progress.
11. Maintenance of quality and work standards.
12. Effect of proposed changes on progress schedule and coordination.
13. Other business relating to Work.
27.
Protection of Finished Works
The Contractor shall carefully protect his own finished work, the works of his subcontractors and the
works of Local Authorities if any, up to the time of completion and final handover of the project. The
Contractor shall be liable for the reinstatement of any work damaged during the progress of the Works,
caused by any reason whatsoever.
10
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 02 : EARTHWORKS
(i)
Scope
This specification covers all necessary work required for the excavations from existing excavated
levels to final foundation’s bottom levels. Backfilling and other sundry works in accordance with the
Drawings and/or Bills of Quantities and as directed by the Engineer.
(ii)
Soil Information
The Contractor shall visit and ascertain the nature of the ground to be excavated and the work to be
done and shall accept all responsibility for the cost of the work involved.
The Contractor in further shall read the Geotechnical report. The Contractor shall conduct at his own
expense any further testing investigations to satisfy himself as to the soundness of the available
information.
(iii) Standards
The Contractor shall comply with the following Codes of Practice:
A) ASTM
A 328/328M-00 : Specification for Steel
Sheet Piling. C 33-02a
C 88-99a
Sulfate.
C 117-95
: Specification for Concrete Aggregates.
: Test Method for Soundness of Aggregates
by use of Sodium or Magnesium
: Test Method for Material Finer Than 75μm (No. 200) Sieve in Mineral
Aggregates by Washing.
C 131-01
: Test Method for Resistance to Degradation
of Small-Size Coarse Aggregate by
Abrasion and Impact in the Los Angeles Machine.
D 421-85(1998)
: Dry Preparation of Soil Samples for
Particle Size Analysis & Determination of
Soil
Constants.
D 1140-00
: Amount of material in Soils Finer than 200
Sieve.
D 1556-00
: Density of Soil in Place by the Sand-Cone
Method.
D 1557-00
: Compaction Characteristics of soil Using
Modified Effort (2,700 kN-m/m3).
D 1883-99
: CBR of Laboratory Compacted Soils.
D 2922-01
: Density of Soil and Soil-Aggregate in
Place by Nuclear Methods. (Shallow Depth)
D 4318-00
: Liquid & Plastic Limits & Plasticity Index
of Soils.
B) BS
11
.
Technical Specifications
_____________________________________________________________________________________________________________
BS 1377
BS 812
B.S 6030: 1981
B.S. 8004: 1986
C.P. 102/B.S.8102/B.S.8215
(iv)
: Method of Test for Soils for Civil
Engineering Purposes.
: Testing Aggregate.
Earthworks
Foundations
Protection of the building against water from the
ground
Site Preparation
Excavation Permits
The Contractor shall be responsible for obtaining all permits relating to excavation works and shall
bear all costs involved. The Contractor shall abide by all conditions, etc. laid down in such permits.
Existing Services
The Contractor shall ascertain the whereabouts of all existing services on the Site, both above and
below ground. Such services shall be protected, maintained, removed, sealed or rerouted in a manner
prescribed by the Public Authorities concerned at the Contractor's own expense as specified under
"Locating, Protecting Maintaining and Diverting Services and Public Utilities". Excavations to locate
services shall be carried out by hand.
1.
Setting Out
a. The Contractor shall stake-out the work as shown on the Drawings and secure the
Engineer's approval of his stake-out before proceeding with construction. If, in the
opinion of the Engineer, modification of the line or grade is advisable before or after
stake-out the Engineer will issue detailed instructions in writing to the Contractor for
such modification and the Contractor shall revise the stake- out for further approval in
accordance with the relevant Clause of the Conditions of Contract.
2. Excavation
a. The excavations are to be executed to the widths shown on the Drawings, and to the
depths below existing ground levels as directed by the Architect. If the Contractor
excavates to any widths or depths greater than those shown in the Drawings or as
instructed by the Architect he shall at his own expense fill in such widths or depths of
excavation to the satisfaction of the Architect.
b. Level and compact the bottom of all excavations to receive concrete, from stepping if
necessary or directed to allow for sloping ground, ground and water excavation before
pouring concrete
c. The Contractor shall report to the Architect when formation levels have been obtain
d. Excavations made below required formation levels shall be filled with plain concrete
(1:3:6) at the Contractor’s expense.
3. Excavation for Foundations
a. The levels to which the Contractor shall excavate are shown on the Drawings. Should
it be found necessary to reach a more suitable stratum, the Contractor shall perform all
additional excavation as directed by the Engineer.
b. During excavation for foundations, the bottom layer of excavation of minimum 150
mm in thickness, shall be left undisturbed and subsequently removed manually only
12
.
Technical Specifications
_____________________________________________________________________________________________________________
c.
d.
e.
f.
when the concrete blinding is about to be placed in order to avoid softening or
deterioration of the surfaces of the excavation.
Bottom of all excavations shall be formed to correct levels as shown on the Drawings
or as directed in writing by the Engineer and shall be trimmed, leveled and well
cleaned before pouring any concrete.
In the event of the Contractor excavating deeper than the levels shown on the
Drawings he shall make up the difference between levels with concrete Grade 15 at his
own expense.
Should loose soil, bad ground or cavities be encountered within any part of the
excavations the Contractor shall remove such matter and fill to the appropriate levels
with hard-core or other approved fill material leveled and compacted to the Engineer's
satisfaction.
After each excavation is complete, the Contractor shall notify the Engineer to that
effect, and no concrete shall be placed until the Engineer has approved the excavation
and the character of the foundation material.
4. Excavation for Trenches
a. The Contractor shall excavate trenches and provide all planking and strutting
necessary to install all drainage, sewer, water supply, electrical and telephone cables to
the lines and grades complete in strict conformity with these specifications, applicable
Drawings and/or as directed by the Engineer.
b. The bottom of the trenches shall be accurately graded to provide uniform bearing and
support for each section of the pipe on undisturbed soil at every point along its length,
except for the portions of the pipe where it is necessary to excavate for bell-holes and
for proper sealing of joints. Bell- holes and depression for joints shall be dug after the
trench bottom has been graded.
c. Care shall be taken not to excavate below the depths indicated. Where rock is
encountered, the rock shall be excavated to the required depth. Uneven surfaces of the
bottom of trench shall be excavated 150 mm deeper. Such depth, if in rock, shall be
backfilled with concrete grade 15 as specified under “Section 03 – Concrete” and
when in earth, shall be backfilled with approved sand at the Contractor's own expense.
Whenever unstable soil, which in the opinion of the Engineer, is incapable of properly
supporting the pipe or duct is encountered in the bottom of the trench, such soil shall
be removed to the depth required and the trench backfilled to the proper grade with
sand, fine gravel or other suitable material approved by the Engineer.
5. Excavation in Rock
d. Rock shall be defined as boulders, exceeding 0.25 m3 in volume or any kind of stone or
rock formation which in the opinion of the Engineer requires for its removal drilling and
blasting, wedging, sledging or barring, or breaking up with a power- operated hand tool.
The definition shall exclude any soft or disintegrated rock which can be removed with a
hand pick or mechanical excavator or shovel, or loose, shaken or previously blasted rock
or broken stone in rock fillings or elsewhere. Blasting by explosive shall not be
permitted.
13
.
Technical Specifications
_____________________________________________________________________________________________________________
6. Disposal of Unsuitable and Surplus Excavated Materials
Upon the order of the Engineer, all unsuitable and surplus excavated materials shall be
immediately removed, loaded and transported off Site area by the Contractor to dumps
located by and approved by the local authorities concerned.
Backfilling and Filling
7. Earth –
Filling obtained from excavations / off site is to be free from weeds, roots, vegetable or
other unsuitable materials and is to compacted in layers each of not more than 225mm
finished thickness. Each layer to be well watered before the subsequent layers is filled
in.
8. Hardcore –
Hardcore for making-up levels under floors etc. shall be good hard stone, ballast or
quarry waste (not clay or similar soft stone) to the approval of the Architect passing not
greater than 150mm ring or to be 75% of the finished thickness of the layers being
compacted whichever is the lesser and graded to contain sufficient small pieces to fill
all voids so that is can be thoroughly compact. The filling is to be laid in layers each
consolidated not exceeding 225mm thick watered and compacted by hand or mechanical
tempers. The top surface of the hardcore is to be blinded with 50mm layer of sand
Material for backfilling and filling shall be compactable reverbed and base course.
The Contractor shall backfill or fill for:
a) Site leveling for buildings and landscape works. This work shall be done by filling to the
required levels with allowance for any subsequent settling.
b) Backfill below and around foundation (Engineering Fill) shall be done in layers not
exceeding 25cm thickness when compacted to be watered and compacted with mechanical
compactors to the required elevations, the upper 1m of the fill shall maintain 98% modified
Proctor of maximum dry density while the rest shall have 95% modified Proctor test of
maximum dry density.
c) The material to be used for filling and backfilling whether excavated from within the site or
imported from outside the site shall satisfy the AASHTO classification for granular material
and falling within one of the following subgroups:
Subgroup
sieve
A-2-4
A-2-5
A-2-6
% Passing No.
200
LL
PI
35 max.
40 max
10 max.
35 max.
41 min
10 max.
35 max.
40 max
11 min
Classification tests shall be carried out to determine the suitability of material prior to the start
of filling and backfilling work.
14
.
Technical Specifications
_____________________________________________________________________________________________________________
The Contractor shall be responsible for any depression resulting from defective backfilling or
filling, and he shall reconstruct or repair any damages to structures, pipelines or trenches
resulting from defective backfilling or filling at his own expense.
9. Surface Treatment
Naturally occurring sand with minimum salinity content shall be use for sand blinding. .
10. Damp Proof Membrane
Polythene sheeting shall be 1000 gauge, joint shall be treble with 150mm fold and taped
300mm interval with 50mm wide plastic tapes. The sheeting shall be laid loose with wrinkles
to permit shrinkage up to 15%.
11. Requirements & Testing
The following requirements, tests and frequencies shall be followed:
Density and OMC for each fill material as defined by ASTM D1557 Method D and determined
in an approved laboratory shall be referenced to the Engineer. The percentage of compaction
shall be determined by the percent of maximum dry density at OMC in accordance with
ASTM D1557 Method D.
If some of the materials are larger than 19 mm the maximum density shall be corrected by the
following formula:
D = (Pf, Df)/100 + (Pcx0.90Dt)/100.
Where D = Corrected maximum dry density.
Pc = Percent of material retained on the 19 mm sieve.
Pf = Percent of material passing the 19 mm sieve.
Df = Maximum density of material passing 19 mm sieve.
Dt = Bulk specific gravity of material retained on 19 mm sieve multiplied by 1000 kg/m².
The area of excavation and the length of trench open at any one time shall be controlled
according to the site conditions and subject to limits as directed by Engineer.
Excavation support system (wood or steel sheeting, soldier piles, wood lagging and secant pile
walls) and bracing shall be cut off or left in place at elevations/locations determined and as
directed by the Engineer.
Well points and pumps shall be installed under the supervision of competent representatives of
specialist sub-contractors in accordance with the requirements specified under the relevant
clauses/sections.
During progress of work, earth-moving operations shall be conducted in such a manner so as to
minimize the creation and dispersion of dust.
Suitable and safe ramps or other covered crossings where required shall be provided access to
construction personnel and other users during construction, and shall be removed on completion.
12. Storing of Suitable Excavated Materials
During excavation, materials suitable for backfill and fill shall be stockpiled on the Site at
sufficient distance from the sides of the excavation to avoid over-loading and prevent any cavein or mixing with the concrete during the construction of foundations.
13. Workmanship
15
.
Technical Specifications
_____________________________________________________________________________________________________________
Materials for backfilling shall comply with and be laid in accordance with BS 6031:1981 Code
of practice for earthworks.
Approved suitable excavated material shall be used on the backfilling and filling next to
footings, foundations, underground structures etc. & shall be laid in layers not exceeding
thickness shown on drawings & compacted with compaction equipment or mechanical tampers
when not possible to use such compaction equipment, as approved by the Engineer.
A relative compaction of at least 95% of the Laboratory maximum dry density shall be
achieved at optimum moisture content determined in accordance with Test 13 of BS 1377.
Each layer of backfill shall be inspected, tested and approved by the Engineers, prior to
commencement of the next layer.
Should the quantity of excavated material be not sufficient for the process of backfill and fill,
the Contractor shall obtain the quantity required of such backfill and fill from approved borrow
pits and transport it to the Site of work at his own expense.
No backfill shall be executed until the footings; foundations, etc. have been inspected,
measured and approved by the Engineer.
Trenches shall not be backfilled until all required tests are performed and until the Engineer
has verified that the pipes and cables have been installed in accordance with the Specifications
and the Drawings. Unless otherwise stated in the Specification, selected fine dry material free
from stones, organic matter, lumps and deleterious materials shall be carefully hand packed
and tamped around the lower half of the pipes and against the sides of the trench, and for the
full width of the trench in order to avoid displacement of the pipes. Filling shall then be
continued to a height of 150 mm above the pipes and leveled across the trench from side to
side with selected fine material which shall be hand packed and consolidated with wooden or
other approved rammers.
Each layer shall then be well rammed and consolidated before the next layer is placed, until the
trench is completely filled to the required levels. Power ramming shall be permitted on layers,
which are 300 mm above the crown of the pipes provided that all the lower layers have been
hand rammed to a satisfactory level of compaction and tested in accordance with the
requirements of this specification.
14. Water
Water shall be clean potable water as specified under SECTION 03 – Concrete Works.
15. Concrete
Concrete used as fill for making up to correct levels, areas of over- excavation, shall be, where
required by the Engineer, Grade "14” as specified under SECTION 03 – Concrete Works.
16
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 03 : CONCRETE WORKS
(i)
Reference Standards and Codes.
a. Conform with the BS 8110 Part 1-3: 1985, the Uniform building Code, UBC and any
applicable acts of any authority having jurisdiction, including occupational health and safely
acts and regulations.
b. Where there are differences between the specifications and drawings and the codes,
standards or acts, the most stringent shall govern.
c. Standards referenced by the Standards noted above are to apply even if they are not included
in the list.
The British Standards referred to in this section are:
BS 12 : 1996
:
Ordinary and rapid-hardening Portland cement
BS 146: 1973
:
Portland blast furnace cement
BS 812
:
Methods for sampling and testing mineral aggregates,
sands and fillers
BS 882, 1201
:
Aggregates from natural sources for concrete
BS 1370:1979
:
Low heat Portland cement
BS 1881
:
Method of testing concrete
BS 3148 : 1980 :
Tests for water for making concrete
BS 4027:1980
:
Sulphate resisting Portland cement
BS 5075:1982
:
Accelerating admixtures, retarding admixtures and
water reducing admixtures
BS 5328 : 1981 :
Methods for specifying concrete including readymixed concrete
(ii)
Concrete Mix Design:
Design of Mix:
a. Design the mix in accordance with BS8110 so that concrete will be homogeneous, uniformly
workable.
b. Specified strength: As called for on drawing, OR when walls are integral with columns,
such as foundation walls, cast walls and columns with concrete of the higher specified
strength.
1. Basic Concrete Materials and Methods
Cement
a. The cement shall be ordinary Portland cement, or rapid hardening Portland cement
complying in all respects with the requirements of B.S. 12, “Sulfate Resisting Cement”, shall
comply with B.S. 4027. DO NOT USE High Alumina or Rapid Hardening Cement.
OBATIAN details of source and manufacture of cement for approval.
b. Cement may be delivered to the site either in sealed bags or loose in approved containers.
17
.
Technical Specifications
_____________________________________________________________________________________________________________
c. Cement delivered in bags shall be stored on an elevated platform in not more than 10 bags
high and adequately protected from the extremes of weather and in such a manner that the
cement shall be stored and used in the same order as delivered on site.
d. Damp or partially set cement, or cement containing lumps, or which has deteriorated in any
way, shall not be used in the works.
Aggregates
a. All aggregates shall conform to the relevant requirements of B.S. 882.
b. Fine aggregates mean materials mainly passing the 5mm B.S. mesh sieve.
c. Coarse aggregates mean materials mainly retained on the 5mm B.S. Sieve and of such
maximum size as may be described hereinafter.
d. Aggregates shall consist of naturally occurring sand, gravel or stone, crushed or uncrushed
and shall be hard, strong, durable clean and free from adherent coating. The shape of the
aggregate shall be rounded, angular or naturally irregular and the presence of laminated or
flaky materials shall be limited to such an extent as in the opinion of the Engineer will not
adversely affect the strength of the concrete.
e. The presence of clay, slit, fine dust, or organic impurities in the aggregates shall be limited
to the extent allowed in Clause 3 of B.S. 882.
f. All aggregates shall be stored on the site on clean platforms free form direct contact with the
ground and in separate bins or batches for each grading and covered for protection from the
weather. The floor shall be slopping so as to allow quick drainage of surplus water.
Sufficient time of the storage on the site before use must be allowed to facilitate the drainage
of excess water.
g. The grading and cleanliness of the aggregates shall generally be tested on the site under
supervision of the Consultant or his representative.
2. Grading of aggregate
Course aggregate shall be prepared as single sized and blended to produce a normal size
grading. The combined grading shall be within the appropriate grading limits laid down in BS
882 and as described below.
The gradation of fine aggregate shall be in accordance with BS 882 and shall be crushed
aggregate from a source approved by the Engineer or as indicated on Structural drawings.
All-in aggregate shall be permitted for low-grade concrete only.
For normal use, aggregates shall consist of fine aggregates (those passing a 5 mm (3/16") sieve,
and coarse aggregates (those retained on a 5 mm (3/16") sieve batched separately which, when
combined together, give a grading curve which lies within the following limits:
Sieve Size
20.0 mm (3/4")
10.0 mm (3/8")
5.0 mm (3/16")
2.36 mm (No. 7)
1.18 mm (No. 14)
600
(No. 25)
μm
% Passing by wt.
100
45 - 75
30 - 48
23 - 42
16 - 34
9 -2
18
.
Technical Specifications
_____________________________________________________________________________________________________________
300
(No. 52)
2 -1
μm
150
(No. 100)
0 – 15
μm
The amount of material passing BS 75 micron sieve in the combined aggregates when tested in
accordance with BS 812 (wet sieving method) shall not exceed the following limits: Fine aggregate
3% by weight
Coarse aggregate 1% by weight
3. Sampling of Aggregates
Sampling and testing of aggregates when required by the Engineer shall be carried out in
accordance with BS 812. If adequate laboratory facilities do not exist on site, samples must be
taken and sent to a testing laboratory approved by the Engineer. Samples of about 0.015m3 (1/2
cu.ft.) and 0.03 m3 (1 cu.ft.) of fine and coarse aggregate shall be sent in suitable airtight
containers.
4. Testing of Aggregates
All fine and coarse aggregates shall be imported from sources approved by the Engineer and
shall be within the limits laid down in the table below in respect of contamination and reactivity:
Relevant Tests and Standards for Aggregates
Property
Method of test & Standards
Grading
BS 812: Part 103 (Dry)
Surface texture
Descriptive, BS 812
Water absorption
Weighing dry & saturated
ASTM C 128 / C127
Fine Aggregate
Soundness 5 Cycles
ASTM C 88
MgSO4
Na3SO4
12 %
Drying shrinkage
BS 812: Part 120
Shrinkage
Shell content
Coarser than 10 mm
BS 812 Part 106
Size 2.36 & 5 mm
Finer than 2.36 mm
Particle shape
BS 812 Part 105.1
Flakiness index
Elongation index
BS 812 Part 102.2
Specific Gravity
ASTM C 128/C 127
Mechanical
BS 812: Part 111
Properties
Part 112
Los Angeles abrasion test (ASTM C-131 or C-535)
Maximum Limit (% by weight)
As detailed under Aggregates
Limit not applicable
Coarse Aggregate 2 %
2.3 %
12 %
0.05% maximum
5 % maximum
10 % maximum
25 % maximum
25 %
Course & Fine aggregate 2.6
10% fines, Minimum
100 kN Impact Value
30 %
30 %
5. Storage of Aggregates
The ready mix concrete supplier shall at all times maintain sufficient quantities of each type of
aggregate considered by the Engineer to be sufficient to ensure continuity of work.
19
.
Technical Specifications
_____________________________________________________________________________________________________________
Each type and grade of aggregate shall be stored separately in bins; in such a manner that
segregation of the various size particles shall not occur. The floors of the bins shall be of
concrete or other approved material having sufficient slope to ensure adequate drainage of
aggregates before being used for concreting.
Suitable precautions shall be taken to avoid contamination of aggregates by wind blown dust,
etc.
Suitable approved shading shall be provided to control the temperature and any contaminations
especially chlorides.
Storage bins shall be emptied and cleaned at regular intervals as approved by the Engineer.
6. Water
Water used for mixing the concrete shall be fresh, clean water, suitable for drinking purposes.
Water for mixing and curing shall be obtained from an approved source and shall be clean and
free of acids, oils, vegetable, and deleterious matter which may have an effect on the strength
and appearance of the hardened concrete by discoloration or efflorescence.
The Contractor, when required by the Engineer, shall arrange for analysis of samples of the
water to be made by an approved testing laboratory and the water shall comply in all respects
with the requirements of BS 3148:1980.
The PH value of water shall be within the range of 7-9 and the concentration of inorganic
contamination shall not exceed the values indicated below:
Dissolved solids excluding those listed below
2200 ppm 0.20%
Sulphates, alkali carbonates or bicarbonates
1000 ppm
0.10%
- Chlorides
500 ppm 0.05%
- Suspended solids
2000 ppm 0.20%
7. Admixtures
The use of admixtures to the concrete to accelerate or retard the setting or to improve the
workability shall be subjected to the approval in writing of the Consultant in every case.
Use only if specified or approved. Admixtures to satisfy requirements of BS 5077. Make trial
mixes and in consultation with the Engineer adjust the dosage and/or mix proportions in order
to give suitable properties in the fresh and hardened concrete.
Do not use admixtures containing calcium chloride or proprietary admixtures containing more
than 0.02% of equivalent or hydrous calcium chloride by weight of cement in the final mix.
8. Batching
a. All batching shall be carried out in accordance with B.S. 811: Part 1:1985.
9. Mixing
a. All mixing shall be carried out only in accordance with B.S. 8110: Part 1: 1985
b. The concrete shall be mixed only in mechanical mixers of an approved design. The
constituents small be mixed in the machine until a concrete of uniform color and
consistency is obtained.
c. The mixing machine shall be well washed out with clean water after every use.
d. The approval of the project supervisor/consultant architect must be obtained before handmixing is commenced and not more than 0.3m³ shall be mixed at a time, and shall done
on a properly constructed platform.
20
.
Technical Specifications
_____________________________________________________________________________________________________________
CONCRETE MIXES: Make concrete mixes having the appropriate strength grade to produce finished
work as scheduled in this Clause and in the General structural Notes drawing or as otherwise directed.
COMPLIANCE WITH BS 5328: Constituent materials, composition of mixes, production of concrete,
information to be provided, sampling, testing and compliance to be in accordance with BS 5328 unless
otherwise specified.
READY-MIXED CONCRETE used provided that it is obtained from a plant which holds a current
Certificate of Accreditation under the Quality Scheme for Ready-mixed Concrete. each mix must be
obtained from only one source unless otherwise approved. Confirm name and address of depot(s) to the
Engineer before any concrete is delivered. Retain all delivery notes for inspection. (Delivery ticket to
give : (See separate sheet).
- Name and number of ready-mixed concrete dept.
- Serial number of ticket
- Date
- Truck number
- Name of purchaser
- Name and location of job
- Grade or mix of concrete including minimum cement content if specified.
- Workability
- Type of cement
- Nominal maximum size of aggregate
- Type name and quantity of admixtures, if included
- Quantity of concrete in cubic meters
- Time of loading
- Time of introduction of the mixing water or of cement if later than the loading time.
- Type of aggregate
10. Testing and Certification of Concrete
COMPLETE CORRELATED RECORDS must be maintained for each mix type, including:
- Composition of the mixes tested, including any admixtures.
- All sampling and site tests.
- Identification marks or numbers of all specimens tested in the laboratory.
- The location of the part(s) of the structure represented by each sample.
- The location in the structure of the batch from which each sample has taken.
Test Reports
Sieve analysis, mechanical properties and deleterious substance content for coarse and fine aggregate.
11. Transporting
a. Concrete shall be transported after mixing as quickly as possible by such means as will
prevent segregation of the constituents.
b. Concrete shall be deposited as near as possible to its final position to avoid re-handling.
Concrete which has set or partially set during transportation shall not be used.
21
.
Technical Specifications
_____________________________________________________________________________________________________________
12. Placing
a. Clean forms and reinforcement just before placing concrete.
b. During hot weather conditions, do not use concrete mixed more than 1 hour after introduction
of mixing water or 1.5 hours during other periods, unless the concrete mix has been designed
with appropriate admixtures to allow longer time before placing.
c. Pumping concrete: this method shall be used only if the velocity of the concreting causes no
separation of the constituents.
d. Concrete shall be placed within 15 meters of leaving the mixer
- Record time, date and location of all pours.
- OBTAIN Engineer’s approval before any pour.
- Place while sufficiently plastic for full compaction. Do not add water or re-temper mixes.
- Place in final position in one continuous operation up to construction joints. Avoid formation of cold
joints.
- Do not discharge from an excessive height or through reinforcement or other obstructions in a way,
which may cause uneven dispersal, segregation or loss of ingredients. Use suitable chutes or trunking
to place concrete where necessary.
- Place in layers no thicker than can be effectively compacted with the equipment being used.
- Take appropriate measures specified hereinafter for casting thick concrete slabs more than 1000mm
thick.
- Do not use vibrators to make concrete flow horizontally into position, except where necessary to
achieve full compaction under void formers and cast in accessories and at vertical joints.
- Use appropriate admixture (e.g. super-plasticizer) to place self-flowing and self-compacting concrete
in heavily reinforced sections.
13. Compaction
a. The concrete shall be well compacted by the use of immersion vibrators. The top surface of
slabs shall be tamped with a heavy tamping board which will be so constructed with handles
to allow the operation from a standing position.
b. The placing of concrete in slabs shall proceed in strips so that the free edge which is not
compacted against an existing concrete face or shutter shall be covered by the new concrete
in the next strip before the initial set of the concrete has taken place. The free edges of the
strip shall be covered with wet Hessian whilst it is not being worked on.
c. The concrete shall compacted in every case so as to fill the moulds completely and to fill the
spaces between and around the reinforcing bars so as to produce a solid dense mass, free
from voids.
Fully compact concrete to full depth (until air bubbles cease to appear on the top surface), especially
around reinforcement, cast-in accessories, into corners of formwork and at joints. Ensure amalgamation
with previous batches, but do not damage adjacent partly hardened concrete. Use mechanical vibrators
of not less than 10,000 oscillations per minute.
14. Curing Concrete
a. Cure all concrete in accordance with BS 8110, except as specified.
b. The elements shall have a basic curing with continuous wetting for a period not less than 3
consecutive days which shall begin immediately after placement of the concrete.
22
.
Technical Specifications
_____________________________________________________________________________________________________________
c. Concrete shall not be laid during heavy rain and freshly laid concrete shall be suitably
protected by tarpaulins so that if heavy rainstorms should occur before the concrete has
sufficiently hardened it is protected against the rain washing away the mortar. Surfaces on
or against which concrete is to be placed shall be protected from becoming excessively wet
prior to concreting.
- Prevent surface evaporation from concrete throughout the period(s) specified below by:
- Retaining formwork in position and, if necessary, covering exposed surfaces immediately after
striking and
- Covering top surfaces of fresh concrete immediately after completion of placing and compacting
each bay, removing covering only to permit any finishing operations and replacing immediately
thereafter.
- Maintain detailed records of location and timing of casting of individual batches, removal of
formwork and removal of coverings. Keep on site, available for inspection.
- Coverings for curing may be suitable impervious sheet materials or a suitable curing compound with
an efficiency of at least 75%, and:
- Must be effective in preventing evaporation of water from the concrete, particular attention being
paid to sealing at edges and junctions.
- Must not disfigure permanently exposed surfaces.
- Must not affect the satisfactory bond of subsequent construction and finishes.
- Until the exposed top faces of fresh concrete are in a state suitable to receive sheets in direct contact
or a sprayed curing compound as applicable, cover with waterproof sheeting held clear of the surface
and well-sealed against draughts at edges and junctions.
CURING PERIODS: Concrete surfaces shall be protected and kept moist by wet hessian cover for a
minimum period of 5 days or as directed be the Engineer.
PROTECTION: Prevent damage to concrete, including:
- Surfaces generally: From site, indentation and physical damage.
- Surfaces to be exposed in the finished work: From dirt, rust marks and other disfiguration.
- Immature concrete: From thermal shock, physical shock, overloading, movement and vibration.
15. Formwork for In-situ Concrete
a. Confirm with the British Standard Specification for design and executing reinforced
concrete structure (BS 8110 Parts 1-3: 1985 “The Structural Use of Concrete”), the uniform
building code and any applicable acts of any authority having jurisdiction, including
occupational health and safety acts and regulations.
b. Where there are difference between the specifications and drawings and the codes, standards
or acts, the most stringent shall govern.
c. Standards referenced by the Standards noted above are to apply even if they are not included
in the list.
d. Formwork, False-work and re-shoring:
Design formwork and re-shoring to safely support vertical and lateral loads until they can
be supported by the structure.
Forms:
a. Formwork Lumber, Plywood and wood formwork materials shall conform to the BS
specification.
23
.
Technical Specifications
_____________________________________________________________________________________________________________
b. Erect, support, brace and maintain formwork to safely support vertical and lateral loads until
they can be supported by the structure.
c. The striking times of the formwork is left to the discretion of the Contractor but shall be in
accordance with B.S. 8110: Part 1: 1985.
d. Form shall be stripped with great care to avoid damage to the concrete and in the case of
plywood forms, metal wedges shall not be used to ease the forms. If necessary, timber
wedges may be used with gentle bending action assisted by rapping on the outside of the
forms.
e. Immediately after striking the forms shall be thoroughly cleaned to remove any concrete
which may have adhered to them.
Cleaning and Oiling:
a. All rubbish, particularly chippings, shavings and saw-dust shall be removed from the moulds
before the concrete is placed, and all forms in contact with the concrete shall be cleaned out
thoroughly and treated with an approved mould oil to facilitate the removal of the forms.
b. The mould oil shall be applied as a thin film only so that no free oil is apparent after coating.
Particular care shall be taken in coating ply forms with an appropriate first grade oil to ensure
a perfectly smooth finish to the concrete and to obtain the maximum re-use of the forms.
16. Reinforcement in In-situ Concrete
a. Confirm with the British Standard Specifications for design and executing reinforced
concrete structure (BS 8110 Part 1-3: 1985), the uniform building code and any
applicable acts of any authority having jurisdiction, including occupational health and
safety acts and regulations
b. Mild steel reinforcement shall consist of round bars complying in all respects with the
requirements of B.S. 4449.
c. High tensile reinforcement shall consist of square twisted cold worked bars complying
with B.S 4449: 1988.
d. Where there are differences between the specifications and drawings and the codes,
standards or acts, the most stringent shall govern.
e. Standards referenced by the Standards noted above are to apply even if they are not
included in the list.
Materials:
a. Reinforcing steel: Deformed steel to BS 4449 standards and to material specification shown
on the drawings. Reinforcement to be welded shall also conform to the materials
recommendations contained in BS 4449. Data of the tests are to be provided to prove that
each grade of reinforcement meets specification requirements.
b. A142 reinforcement mesh is manufactured to Bs4483, from cold reduced wire which
complies with Bs4482. Ribbed wire classified as Type 2 and recognized in Bs8110 as Having
improved bond characteristics, is Available as standard material. Each wire intersection is
resistance welded using electronically controlled techniques.
Fabrication and Placing
a. Fabricated reinforcement in accordance with BS specification.
24
.
Technical Specifications
_____________________________________________________________________________________________________________
b. Bend reinforcement once only and at room temperature, without the use of heat or torch. Do
not straighten or re-bend reinforcement.
c. Replace bars which develop cracks or splits.
d. Prior to concreting, accurately place reinforcement, support and secure against displacement,
as indicated on reviewed placing drawings and in accordance with BS 4449.
e. Do not drive or force reinforcement into fresh concrete.
LAPS OR SPLICES: Obtain instructions if details are not shown on drawings.
LAPS in nominal bar reinforcement to be according to BS 8110: Part 1: 1997, if not shown on drawings.
FIX REINFORCEMENT adequately, using tying wire, approved steel clips or tack welding if permitted.
Wire or clips must not encroach into the concrete cover.
SPACERS: In addition to supports shown on drawings or schedules, provide spacers and chairs at not
more than 1 m centers or closer spacing as necessary to support reinforcement in position and maintain
the specified cover. Reinforcement must be fixed in position before the concrete is placed. Cover spacers
to be not closer than 300mm centers and staggered on adjacent parallel bars.
COVER SPACERS: Type(s) which will adequately support the reinforcement, adequately resist
displacement, not cause indentation of the formwork and made from:
Plastics (perforated to at least 25% of their area), or Fiber cement, or
Concrete (strength and durability to match surrounding concrete).
REQUEST Engineer’s inspection of the fixed reinforcement in advance of concrete pouring.
Displacement and Field Bending
a. Great care shall be taken not to disturb the reinforcement during concreting. Any reinforcement
nevertheless displaced shall be re-fixed in its proper position by a competent steel fixer, who
shall be in attendance throughout the period of the concreting operations.
b. Do not field bend reinforcement except where indicated or authorized in writing by consultant./
c. When field bending authorized, bend without heat, applying a slow steady pressure until desired
configuration is achieved.
Construction Joints:
a. Obtain written approval from the consultant for details of construction joints not shown.
b. Continue reinforcement through the joint in its normal position. Any additional
reinforcement across the joints as shown or directed.
Tests:
Tests shall be carried out on reinforcement bars delivered to the job site in an independent laboratory
approved by the Engineer for compliance with the requirements of the above mentioned Standards. At
least 2 samples of each size and type shall be taken as directed by the Engineer and tested.
The Contractor shall provide, in addition, copies of the manufacturer's certificates of test results relating
to the steel reinforcement for each consignment brought to site.
25
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 04 : MASONRY
1. Reference Standards and Codes
a.
b.
c.
d.
Concrete blocks shall comply with requirement of B.S 2028, 1364 except where amended.
Test result shall comply with the requirements of B.S. 2018, 1364.
All stones shall comply with the requirements of B.S. 121.202 for masonry and rubble walls.
Building blocks (sandcrete and concrete) standard sizes of blocks are laid down in BS 6073 part
2: 1981.
2. Materials
Cement – cement used for making mortar shall be as described in “concrete works”
3. Water
Shall be as described in “Concrete Work”.
4. Sand
Sand used for making mortar shall be clean well graded siliceous sand of good sharp hard quality
equal to samples which shall be deposited with and approved by the Architect. It shall be free
form lumps of stone, earth, loam, dust, salt, organic matter and other deleterious substances,
passed through a fine sieve and washed with clean water if so directed by the Architect.
5. Cement Mortar
Mortar described as cement mortar 1.4 shall be composed of 1 cubic meters (1498 Kgs.) of
Portland cement and 4 cubic meters of sand. Other mixes such as 1:3, 1:5 1:6 etc shall be
similarly construed.
6. Mixing of mortar.
The constituent materials shall be measured separately when dry in specially prepared gauge
boxes of sizes to give the proportions specified without consolidation of the contents by ramming
and shaking. Mortar shall be used within 30mins of mixing. No partially or wholly set mortar
will be allowed to be used or re-mixed.
7. Building Walling
Laying and jointing
All blocks shall be well wetted before being laid and the top of walling where left of shall be
well wetted before commencing building. Walls to be kept wet three days after building. No
part of the wall should be allowed to be carried up more than one meter higher at one time than
any other part and such cases the joining shall be made in long steps so as to prevent cracks
arising and all walls shall be leveled round at each stage. Not more than 3 meter height of wall
shall be laid in any one day.
Blocks shall bedded and jointed in cement mortar as described with beds and joints 10mm thick,
all flushed up and grouted solid as the work proceeds.
Bonding
26
.
Technical Specifications
_____________________________________________________________________________________________________________
The blocks shall be properly bonded together and in such manner that no vertical joint in any
one course shall be within 115mm of a similar joint in the courses immediately above or below.
Curing
All walls shall be maintained in a damp condition for at least 24 hours after laying. Walls under
construction shall be dampened by applying water with a brush and no hosing directly on to the
wall shall be permitted. When work ceases on any section of the wall polythene or Hessian shall
be draped over the wall, for at least 24 hours. If Hessian is used, it shall be maintained
continuously wet.
Backfilling
Earth backfilling against walls shall be carried out such that the level of the backfill is always
equal on each side of the wall.
27
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 05 : ROOFING
Materials and Components
All roofing material shall be 28 gauge corrugated iron C.I sheet unless otherwise specified and shall be
approved by the Contract Administrator.
1. Fasteners
Self-drilling screws: Corrosion resistant screws to approval of Engineer.
Nuts and bolts: Corrosion resistant fastenings to approval of Engineer.
Fastenings to timber battens or purlins: Provide fastenings just long enough to penetrate the
thickness of the timber without piercing the underside.
2. Corrugated Metal Roofing and Cladding
Provide a proprietary system of preformed corrugated sheets and all purpose-made accessories
required to complete the installation to roof framing or wall framing. Refer to detailed drawings
for details.
3. Roof Ventilation
Provide proprietary roof mounted ventilators and all purpose-made accessories required to
complete the installation where shown on the drawings to ventilate the roof space.
Provide fabricated ventilators in walls as shown on the drawings to ventilate the roof space.
4. Protection
Keep the roofing and rainwater system free of debris and loose material during construction, and
leave them clean and unobstructed on completion. Repair damage to the roofing and rainwater
system.
If it is necessary to repair minor damage to metal roofing, do so immediately after the damage has
occurred. The Contractor is take care to not damage other surfaces during the repair works.
5. Thermal Movement
Provide for thermal movement in the roof installation and the structure, including movement in
joints and fastenings.
6. Roofing Sheet Installation
Fixings: Provide all fixings required to fix the roof sheeting to the framing so that the entire roof
covering is waterproof and secure. All loose edges are to be fixed down to ensure that they cannot
get loose in high winds.
Expansion joints: refer to drawings for locations of expansion joints in roofs and details of
construction.
7. Ridges and Eaves
Treat ends of sheets as follows:
- Project sheets 50 mm into gutters.
- Close off ribs of ribbed sheeting at bottom of sheets using mechanical means or with purposemade end caps.
28
.
Technical Specifications
_____________________________________________________________________________________________________________
- Turn pans of ribbed sheeting up at tops and down into gutters by mechanical means.
- Provide pre-cut notched eaves flashings and bird proofing wire mesh where necessary.
8. Ridge and Eaves Capping
Finish off along ridge and side eaves edges with purpose-made ridge capping and eaves capping.
9. End laps
Where end laps are unavoidable in roof sheeting, and the sheet profile is not suitable for
interlocking or contact end laps, construct a stepped type lap. Refer to details on drawings as
required.
Length of lap (mm): Laps to ends of sheets should not be less than 150mm and sealed with a
continuous line of silicone sealant between the sheets of roofing.
10. Curved corrugated sheet
Form by rolling from material recommended for curving. Minimise crimping or creasing across
the face of the sheet. Trim off crimped or creased edges and ends.
K-Span roofing where identified on the drawings is to be strictly controlled during the installation
process to ensure that the completed work is of a high standard.
11. Roof Plumbing
Provide the flashings, capping, gutters, rainwater heads, outlets and downpipes necessary to
complete the roof system.
12. Flashings and Capping
Installation: Flash roof junctions, upstands, abutments and projections through the roof. Preform to
required shapes where possible. Cut, notch, bend or dress down as necessary to follow the profile
of adjacent surfaces. Lap joints 150 mm in running lengths. Provide matching expansion joints at 6
m maximum intervals.
Upstands: Flash projections above or through the roof with two part flashings, consisting of a base
flashing and a cover flashing, with at least 100 mm vertical overlap. Provide for independent
movement between the roof and the projection.
Wall abutments: Provide over flashings where roofs abut walls, stepped to the roof slope in
brickwork.
- In masonry: Build cover flashing at least 100mm into the wall at least 250mm above the roof
level. Provide base flashing on roof and provide at least 100mm vertical overlap.
- In concrete: Turn cover flashing at least 30 mm into saw cut grooves at least 250mm above the
roof level, wedge at 200 mm centers with compatible material and render over top of flashing.
Provide base flashing on roof and provide at least 100mm vertical overlap.
Fixing to pipes: Solder, or seal with neutral cured silicone rubber and either of the following:
- Secure with a clamping ring.
- Provide a proprietary flexible clamping shoe with attached metal surround flashing.
13. Gutters
Prefabricate gutters to the required shape where possible. Form stop ends, bends and returns.
Provide overflows to prevent back-flooding.
29
.
Technical Specifications
_____________________________________________________________________________________________________________
Gutter and sump support: Provide framing and lining to support valley gutters, box gutters and
sumps. Line the whole area under the gutters and sumps.
Support: Steel straps as shown on drawings or as approved by the Engineer.
Lining: Timber boards or plywood as shown on drawings or as approved by the Engineer.
Valley gutters: Profile to suit the valley boarding. Nail or screw to the valley boarding at the top
end to prevent the gutter creeping downwards.
Gratings and guards: Provide removable gratings over rainwater heads and sumps:
- Type: Wire mesh cages reinforced with steel bars where required due to size and expected snow
loads. Refer to drawings for details.
Expansion joints: Provide expansion joints in guttering longer than 30 m:
- Type: Refer to drawings for details.
14. Downpipes
Prefabricate downpipes to the required section and shape where possible. Connect heads to gutter
outlets and, if applicable, connect feet to rainwater drains.
Access cover: Provide a removable watertight access cover at the foot of each downpipe stack if
the downpipe is connected to rainwater drains.
Downpipe support: Provide supports and fixings for downpipes.
15. Roof Inspection
The Contractor is to closely inspect the entire roof covering and metal cladding to walls at
completion of the works.
Make good any defects or damage to the sheeting, cappings or flashings. Remove all loose metal
and other rubbish, spare nails, screws, filings and other debris.
Clean down the roof, gutters, downpipe outlets to ensure that it is good condition ready for
occupation.
30
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 06 : WOOD WORK, DOORS AND WINDOWS
WOODWORK
Reference Standards and Codes
Works in this section shall conform with the requirement of B.S. 1186 Part 1, 4048, 1455 and
2604 Part 2
1. Generally
All woodwork shall be carried out in accordance with the drawings and the principles of
first class joinery construction. Unless specifically stated otherwise, sizes shown on
drawings are finished sizes and the Contractor must allow for wrought faces.
2. Qualities of Timber
a. The qualities of timber stated hereinafter are in accordance with the latest BS Standards
Grading Rules.
b. All timber described as Prime Grade is to be First Grade (Grade I).
c. All timber described as selected Grade is to be Second Grade (Grade II).
d. All hardwood is to be Prime Grade (Grade I).
e. All timber for permanent work in the building shall before use be approved by the
Architect for quality in accordance with the foregoing specification for its respective
grade. Any timber not
so approved by the Architect shall be removed from the site forthwith.
3. Seasoning of Timber
All carpentry timbers are to be seasoned to an average moisture content of not more than
20%.
All joinery timbers are to be seasoned to an average moisture content of not more than 15%.
The Contractor is to make available on site a meter for testing moisture content of all timber
delivered.
Pressure Impregnated Timber
 All timber described as "pressure impregnated" shall be impregnated under vacuum and
pressure with "Celcure" or "Tanalith" wood preservative with an average absorption of not
less than 6.7 Kgs. of dry salt per cubic meter. In case of resistant species where this retention
cannot be obtained the timber shall be treated to refusal point. All treated timber shall not be
exposed to wet conditions for at least 14 days after treatment has been carried out. All cut
ends, drilling or abrications on the site producing new surfaces shall be thoroughly brushed
or soaked with "Celcure B" salts applied in accordance with the manufacturer's instructions.
 Any other method of timber impregnation will only be allowed at the Architect's approval.
Such as brush application etc.
a. Hardwood
Hardwood shall be free from woolly texture, soft heart, sap wood, splits shakes, all evidence
of insect of fungi attack and rot all faults caused by compression failure. There shall be no
31
.
Technical Specifications
_____________________________________________________________________________________________________________
waney edges. Hardwood shall be free from knots on exposed faces. Any hardwood showing
visible imperfections will be rejected.
b. Softwood
Timber shall be free from woolly texture, soft heart, sap wood, splits shakes, pith showing
on the surface, sloping grain exceeding one in eight checks, knots exceeding 25mm diameter,
loose know or knot holes and any evidence of insect or fungi attack. There shall be no waney
edges.
c. Plywood
Plywood shall be Exterior Grade except where otherwise stated. Plies shall be bonded
together with adhesives complying with requirements of B.S. 1203 grade WBP. Plywood
shall be free end joints.
d. Nails and screws
Nails shall comply with B.S. 1201, screws shall comply with B.S. 1494 and bolts shall
comply with B.S. 916.
DOORS
Materials and Components
All doors shall be hardwood timber, plywood flush door and steel unless otherwise specified and shall
be approved by the Contract Administrator.
1. Notice
Give sufficient notice so that inspection may be made of the following:
- Door frames standing in place before building in to brickwork.
- Door frames installed before fixing trim.
2. Samples
Submit samples of all hardware items for approval by the Engineer before use in the works.
3. Product Warranties
Automatic sliding door assemblies: Submit a warranty from the supplier and installer for the system
and its installation, for a period of at least twelve months from the date of completion.
Hardware: Submit the warranties offered by the manufacturer for the hardware items provided in the
works.
4. Keys
Key codes: Submit the lock manufacturer’s record of the key coding system showing each lock type,
number and type of key supplied, key number for re-ordering, and name of supplier.
Keys: For locks keyed to differ and locks keyed alike, verify quantities against key records, and
deliver all keys and records to the Engineer at completion.
5. Timber frames
To be constructed with best quality timber. Obtain approval from the Engineer for the timber selection
before use. Construct as shown on the drawings and ensure that all joints are securely made to avoid
distortion of the frame in use.
32
.
Technical Specifications
_____________________________________________________________________________________________________________
6. Steel Frames
To be folded from metallic-coated steel sheet sections, joints to be continuously welded, including
necessary accessories such as buffers, strike plates, spreaders, fixing ties or brackets, and suitable for
fixing specified hardware.
Finish: Grind the welds smooth, prepare and paint the welded joints with primer. Then prime the
entire frame.
Hardware and accessories: Provide for fixing hardware including hinges and closers, using 4 mm back
plates inside the frame. Screw fix the hinges into the back plates.
Base metal thickness:
- General: ≥ 1.1 mm.
- Fire rated door sets: ≥ 1.4 mm.
- Security door sets: ≥ 1.6 mm.
7. Butt hinge sizes
Refer to Hinge table A and Hinge table B in which length (l) is the dimension along the knuckles,
and width (w) is the dimension across both hinge leaves when opened flat.
- Steel, stainless steel, brass, bronze butt hinges for timber doors in timber or steel frames: To Hinge
table A.
- Aluminum hinges for aluminum doors, or for doors of other materials in aluminum frames: To
Hinge table B.
8. Hinge materials
Aluminum hinges: High tensile aluminum with fixed stainless steel pins in nylon bushes, and with
nylon washers to each knuckle joint.
Doors fitted with closers: Provide low friction bearing hinges.
Hinge pins
Exterior or security doors opening out: Provide fixed pin hinges.
Hinge Table A
Nominal hinge size
l x w x t (mm)
Mass (kg)
70 x 50 x 1.6
85 x 60 x 1.6
100 x 75 x 1.6
100 x 75 x 2.5
100 x 75 x 3.2
125 x 100 x 3.2
16
20
30
50
70
80
Hinge table B Nominal
hinge size
l x w x t (mm)
Knuckles
Door leaves not exceeding any of the
following
Width (mm)
Thickness (mm)
620
30
820
35
920
40
920
50
1020
50
1220
50
Door leaf not exceeding
mass (kg)
Minimum construction
Screws/hinge leaf
33
.
Technical Specifications
_____________________________________________________________________________________________________________
100 x 70 x 3
100 x 80 x 3.5
30
50
3
5
3
4
9. Number of Hinges
Provide 3 hinges for doors up to 2200 mm high, and 4 for door leaves between 2200 mm and 3000
mm high.
10. General Door Hardware
Provide hardware of sufficient strength and quality to perform its function, appropriate to the intended
conditions of use and climate and fabricated with fixed parts firmly joined.
11. Bolts
Provide bolts including barrel bolts and tower bolts with associated hardware, including lock plates,
ferrules or floor sockets.
12. Furniture
Provide lock and latch furniture suitable for use with the lock or latch to which it is installed with the
corresponding level of performance.
13. Strike Plates
Use strike plates provided with the locks or latches.
14. Fire Rated Door Closers
Provide closers tested and certified for use as components of fire door assemblies.
15. Door Controllers Performance
Provide door controllers, including door closers, floor or head spring pivots which are suitable for the
door type, size, weight and swings required and the operating conditions, including wind pressure.
16. Fixing and Fasteners
Materials: Use materials compatible with the item being fixed and of sufficient strength, size and
quality to perform their function.
Concealed fixings: Provide a corrosion resistant finish.
Exposed fixings: Match exposed fixings to the material being fixed.
Support: Provide appropriate back support (for example blocking and backing plates) for hardware
fixings.
Packing: Pack behind fixing points with durable full width packing.
Prepared masonry openings: If fixing timber door frames into existing prepared openings with
fastenings through the frame face, make the fastener heads finish below the surface and fill the hole
for a smooth surface finish.
17. Joints
Make accurately fitted tight joints so that neither fasteners nor fixing devices such as pins, screws,
adhesives and pressure indentations are visible on exposed surfaces.
18. Operation
34
.
Technical Specifications
_____________________________________________________________________________________________________________
Ensure moving parts operate freely and smoothly, without binding or sticking and are lubricated.
19. Supply
Deliver door hardware items, ready for installation, in individual complete sets for each door.
- In a separate dust and moisture proof package labelled for the specific door.
- Including the necessary templates, fixings and fixing instructions.
20. Cleaning
The Contractor is to clean all frames, doors, glass, hardware at completion. Any damage to frames and
doors, or broken glass is to be repaired or replaced to the satisfaction of the Engineer.
21. Adjustment
Leave the hardware properly adjusted with working parts in working order and lubricated where
appropriate.
WINDOWS
Materials and Components
All windows shall be steel casement unless otherwise specified and shall be approved by the Contract
Administrator.
22. Notice
Give sufficient notice so that inspection may be made of the following:
- Openings prepared to receive windows (where windows are to be installed in prepared openings).
- Fabricated window assemblies delivered to the site, before installation.
- Commencement of window installation.
23. Hardware
Provide hardware of sufficient strength and quality to perform its function, appropriate to the intended
conditions of use and climate and fabricated with fixed parts firmly joined.
24. Fixed Screens
Provide fixed screens to the window frames with a clipping device which permits removal for
cleaning.
25. Hinged Screens
Hinge at the side to give access to opening sash.
26. Sliding Screens
Provide a matching aluminum head guide, sill runner, and frame stile sections for screens not part of
the window frame
27. Installation
Install windows so that the frames:
- Are plumb, level and straight within acceptable building tolerances.
35
.
Technical Specifications
_____________________________________________________________________________________________________________
- Are fixed or anchored to the building structure to resist the wind loading.
- Will not carry any building loads, including loads caused by structural deflection.
- Allow for thermal movement.
28. Flashing and Weathering
Install molds, sealant and cement pointing as required so that water is prevented from penetrating the
building between the window frame and the building structure.
29. Fixing and Fasteners
Materials: Use materials compatible with the item being fixed and of sufficient strength, size and
quality to perform their function.
Concealed fixings: Provide a corrosion resistant finish.
Exposed fixings: Match exposed fixings to the material being fixed.
Support: Provide appropriate back support (for example blocking and backing plates) for hardware
fixings.
Window fastener spacing (nominal): 600 mm.
Window fasteners: Conceal fasteners where possible.
Packing: Pack behind fixing points with durable full width packing.
Prepared masonry openings: If fixing timber windows into existing prepared openings with fastenings
through the frame face, make the fastener heads finish below the surface and fill the hole for a smooth
surface finish.
30. Joints
Make accurately fitted tight joints so that neither fasteners nor fixing devices such as pins, screws,
adhesives and pressure indentations are visible on exposed surfaces.
31. Operation
Ensure moving parts operate freely and smoothly, without binding or sticking and are lubricated.
32. Supply
Deliver window hardware items, ready for installation, in individual complete sets for each window.
- In a separate dust and moisture proof package labelled for the specific window.
- Including the necessary templates, fixings and fixing instructions.
Refer to the drawings for details of windows and for details of window hardware.
33. Cleaning
The Contractor is to clean all frames, glass, hardware at completion. Any damage to frames, or broken
glass is to be repaired or replaced to the satisfaction of the Engineer.
34. Adjustment
Leave the hardware properly adjusted with working parts in working order and lubricated where
appropriate.
36
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 07 : METAL WORK
1. Notice
The Supervising Engineer shall give sufficient notice so that inspection may be made of the following:
- Shop fabricated or assembled items ready for delivery to the site.
- Site erected assemblies on completion of erection.
2. Samples
Submit samples to the Sample table for approval by the Engineer.
Sample table
Description
Each type of metal item to be purchased
Typical joints of welded or fabricated items
Finished sample of each type of painted or anodized metalwork
indicating range within color specified and finish
The finish to all stainless steel items
No. of samples
2
2
2
2
Manufacturer’s data: Submit manufacturer’s published product data and details for purchased items.
Stainless steel: For each batch of stainless steel supplied to the works, submit the certificate of
compliance specified for the applicable standard.
3. Metals
Performance: Provide metals suited to their required function, finish and method of fabrication, in
sections of strength and stiffness adequate for their purpose.
4. Rivets
Use blind rivets where available in the required metal.
5. Masonry anchors
Proprietary types comprising screws or bolts in self-expanding sockets.
6. Masonry plugs
Screws in purpose-made resilient plastic sockets or fixed to timber plugs built into the wall surface.
7. Fasteners
Materials: Provide fasteners in materials of mechanical strength and corrosion resistance at least equal
to that of the lowest resistant metal joined.
37
.
Technical Specifications
_____________________________________________________________________________________________________________
To copper and copper alloys: Provide copper or copper-alloy fixing devices only.
To aluminum and aluminum alloys: Provide aluminum alloy or stainless steel fixing devices only.
To stainless steel: Provide appropriate stainless steel materials only.
8. Fabrication
Workshop: Fabricate and pre-assemble items in the workshop wherever practicable.
Edges and surfaces: Keep clean, neat and free from burrs and indentations. Remove sharp edges
without excessive radiusing.
Tube bends: Form bends in tube without visibly deforming the cross section.
Color finished work: Match colors of sheets, extrusions and heads of fasteners.
Thermal movement: Accommodate thermal movement in joints and fastenings.
9. Fabrication tolerances
ensions.
10. Joints
Fit joints to an accuracy appropriate to the class of work. Finish visible joints made by welding,
brazing or soldering using grinding, buffing or other methods appropriate to the class of work, before
further treatment.
Self-finished metals: Free of surface colour variations, after jointing.
Joints: Fit accurately to a hairline where feasible.
11. Marking
Provide suitable and sufficient marks or other means for identifying each member of site-erected
assemblies, and for their correct setting out, location, erection and connection.
12. Splicing
Provide structural members in single lengths where possible. Obtain approval of the Engineer for
locations of joints where splices in metalwork cannot be avoided.
13. Brazing
General: Ensure brazed joints have sufficient lap to provide a mechanically sound joint. Do not used
butt joints relying on the filler metal fillet only.
Quality: Provide finished welds which are free of surface and internal cracks, slag inclusion, and
porosity.
14. Welding stainless steel
All tube, angle or thick plate material is to be welded unless noted otherwise on the drawings. Ensure
that welds do not discolor the final surface finish in the welding process.
15. Riveting
Riveting may be used only to join stainless steel sheet or strip less than 1 mm thick. Drill (not punch)
the rivet hole, and drive the rivet cold. On completion, clean and passivate the riveted assembly.
16. Soldering
Do not solder stainless steel.
38
.
Technical Specifications
_____________________________________________________________________________________________________________
17. Assembly
Material: Refer to drawings and BOQ for details of member sizes and assembly of components.
18. Fabrication
Method: Welding.
Joints: Produce smooth unbroken surfaces at joints. Make end-to-end joints over an internal sleeve.
Bends: Make changes of direction in rails by evenly curved pipe bends.
Free ends: Seal the free ends of pipes with fabricated or purpose-made end caps.
19. Fixing to structure
Provide fabricated predrilled or purpose-made brackets or post bases, and attach the pipework to the
building structure with fixings, including bolts into masonry anchors, and coach screws or bolts into
timber, of metal compatible with the pipework.
20. Galvanizing
If possible, complete fabrication before galvanizing; otherwise apply a zinc-rich primer to affected
joint surfaces.
21. Painting
If possible, complete fabrication before painting; otherwise apply paint to affected joint surfaces after
fixing on site. Make good all damaged painted surfaces before completion of the building works.
22. Maintenance manual
General: Submit manufacturer’s published recommendations for service use.
23. Cleaning
Temporary coatings: On or before completion of the works, or before joining up to other surfaces,
remove all traces of temporary coatings used as a means of protection.
39
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 08 : PLUMBING INSTALLATION
General
All plumbing works shall comply with the requirements of Water Authority and Waterworks
Regulations.
Pipe work under this section shall include:
(i) External water mains and fire services mains within the site boundary.
(ii) Rising water and fire services mains.
(iii) Internal water distribution pipe work.
(iv) Washouts, overflows and all connections to tanks.
Plastic pipes
Plastic pipes shall be un-plasticized PVC pipes complying with replacing BS 3505 of the pressure rating
class D or higher as specified, with fittings complying with BS 4346:Pt. 1 and Pt. 2
Draw -off taps and valves
Screw-down type draw-off taps and stop valves generally shall comply with BS 1010-2:1973.
Valves and taps installed in public areas, not intended for public use, shall be housed in vandal
resistant and corrosion resistant enclosures.
All valves shall be protected after installation for handing-over in perfect condition on
completion.
All valves shall be suitable for both the working and test pressures of the piping system in
which they are installed.
Unless otherwise specified, all valves shall have a working pressure of not less than 1370 kN/
sq. m.
All valves shall be pressure tested in accordance with the relevant British Standard by the valve
manufacturer before leaving the factory. Test certificate/ report from laboratories approved
by the Water Authority confirming that the valves have been tested in conformance with this
specification to be produced upon request.
Thread in screw connection
Thread-in screw and connection shall comply with BS 21.
Ball valves
Ball valves shall be of the slow closing type, unless otherwise specified. The valve body shall
be robust and shaped to give a good flow pattern. The valve piston shall close in the direction
of flow such that the pressure in the Main shall tend to keep the valve closed and that the
piston seal is afforded protection from the flow by the piston.
All internal parts shall be easily removable for maintenance with the face and piston seals
easily replaceable.
Ball floats shall comply with BS 1968 or BS 2456 and shall be constructed of tinned copper for
fresh water application and of neoprene coated copper for flush water application. All ball floats
shall be spherical.
Lever arms shall be of stainless steel for flush water application. Ball valves for tanks for sizes
50 mm and under shall be bronze complying with BS 1212:Part 1, suitable for high pressure.
For salt water systems the bronze shall be zinc free.
Ball valves for tanks for sizes over 50 mm shall be cast iron body with gunmetal piston, seat
and guide, suitable for high pressure. For salt water systems ball valves shall be of cast iron
body with zinc free bronze piston, seat and guide.
Where ball valves are installed inside sump tanks, extended guide pipes with submerged
40
.
Technical Specifications
_____________________________________________________________________________________________________________
discharge ends shall be provided after ball valves. Guide pipes shall be of diameters not less
than the incoming pipes and shall be holed as appropriate to avoid back-siphoning.
Ball valves for flushing cisterns
Ball valves for flushing cisterns shall be diaphragm type float operated valves complying with
BS 1212:Part 3 with rubber or plastics diaphragms suitable for high, medium or low pressure.
Metal parts of valves shall be suitably coated to prevent corrosion.
Flushing valve
Flushing valve shall be corrosion resistant, made of brass, stainless steel or high grade
thermoplastics and activated by simply pressing on a push-button or lever.
The volume of water per flushing cycle for water closet fitment shall be ranging from 7.5 litres
to 15 litres. In the case of urinals, the discharge volume shall be not less than 4.5 litres for
every basin or stall, or for every metre of a trough urinal.
The flow rate of the flush water shall be adjustable. The flush valve shall maintain a minimum
of 1.5 litres/second flow rate.
The valve shall have such feature to allow it to go through the complete flush cycle and
then shut off automatically, regardless of whether the handle is held down or released. Such
automatic closure shall take place slowly and progressively without hammering effect.
Shower trays
Shower trays shall comply with BS 6340: Pt 8 or ABS capped resin-stone.
Taps
Taps shall be:
Tap complying with BS 816:1997. Operating pressure between 0.3 – 10 bar.
Flow rate 2 - 6 litre per min. Max. water temp. 80 degree aerator. Self-cleaning. Turn-off
control pre-set 0 – 3 sec.
Wash basins
Wash basins shall comply with BS 1188:1974 and shall be made from vitreous china complying
with BS 3402 of the following types as specified:
(i) Under counter basin with overflow.
(ii) Wall hung basin with or without pedestal as specified.
(iii) Semi-recessed basin with or without overflow as specified.
(iv) Counter top basin with or without overflow as specified.
Water closets (W.C.)
Water closet pans shall be vitreous china washdown with horizontal outlet complying with BS
EN 997:2003, white plastic single ring seat and cover with plastic fixing bolts all to BS 1254 and
flushing cistern to BS 7357, complete with 7.5 litres max capacity flushing apparatus, discharge
pipe, ball valve and overflow, of one of the following types as specified:
(i) Low level vitreous china.
Squat Toilet
Squat toilet shall be vitreous china bowl type complying with BS 5520:1977 with 50 mm diameter
of waste outlet, complete with vitreous china automatic flushing cistern complying with BS
1876:1990, chromium plated flush pipes and spreaders to suit the number of appliances in the
range as follows:
(i) 4.5 litres to serve single bowl.
Traps
Traps shall have 75 mm seal, unless otherwise specified. Cast iron traps shall comply with BS
416-1:1990, Table 18.
41
.
Technical Specifications
_____________________________________________________________________________________________________________
Foul Water Drainage Above and Below Ground Level
Plastic pipes
Plastic soil and ventilating pipes and fittings shall comply with BS 4514.
Plastic waste pipes and fittings shall comply with BS 5255:1989. W.C. connectors shall comply with
BS 5627:1989.
Pipes and fittings shall be suitable for their intended use, particularly where non-domestic effluents or
hot liquids in kitchens, laboratories etc. may be discharged into the system.
Granular bedding
Recycled or non-recycled granular bedding material shall be clean, hard, durable, crushed rock or
crushed concrete, broken stone, hard brick, concrete, or other comparable hard inert, approved material
to pass a 25 mm BS sieve, but shall be retained on a 5 mm BS sieve. The material shall be tested as
specified.
Concrete work
Concrete shall be as specified in relevant section of specification and used as follows:
(i) Grade 20/20 - channels, manholes, inspection chambers, gullies, catch pits and all reinforced concrete
work.
(ii) Grade 10/20 - pipe bedding, pipe haunching, pipe surrounds and all other work.
(iii) Grade 10/40 - filling.
Mortar
Mortar for bedding covers or for rendering shall consist of one part cement and three parts clean well
graded sand with just enough water to give plastic consistency.
Floor Gulley or Drain
Floor drain shall be 50mm diameter siphon PVC grille opening including 25mm diameter waste pipe
connected to main grey water waste pipe line.
1. Regulations
The whole of the drainage is to be executed by a registered plumber and drain layer in strict accordance
with the Regulations of Local Authorities and to the satisfaction of the Architect.
2. P.V.C. Drain pipes
P.V.C. drain pipes and fittings shall comply with the requirements of B.S. 4660 : 1973.
3. Pre-cast Concrete Open Channels
Pre-cast concrete invert and side blocks shall be of dense pre-cast concrete free from cracks and spells.
The concrete used shall be nominal 1:2:4 mix. Pre-cast concrete invert and side blocks shall be cast in
steel moulds. All arises shall be true and well defined.
4. Manhole Covers and Frames
Manhole covers and frames shall be of cast iron in accordance with the requirements of B.S. 497.
5. Pipe Laying
Pipe laying shall not commence until the bottom of the trench and the pipe bed have been approved.
Flexible pipes, rigidly jointed, may be joined on the ground surface before lowering into the trench. All
joints shall be supported by slings as the pipes are lowered and the pipe-line must not be deformed to a
greater extent than recommended by the manufacturer. Pipes must be brought to the correct alignment
and inclination, concentric with the pipes already laid. All pipes less than 600 mm in diameter with
42
.
Technical Specifications
_____________________________________________________________________________________________________________
flexible joints must be accurately marked prior to laying to ensure that the correct gap is left in the joint.
An indelible mark shall be made on the spigot end on top of the pipe barrel to the depth of the socket
less the detailed or specified joint gap. After correct jointing the mark should be flush with the face of
the socket. PVC pipes must be stored and handled carefully and must not be subjected to stresses which
shall induce permanent set or ovality. PVC pipes must be protected from the effects of temperature in
accordance with the manufacturer's recommendations.
6. Jointing Pipes
Joints shall be made strictly in accordance with the manufacturer's instructions. The Contractor shall
make use of the technical advisory services offered by manufacturers for instructing pipe jointers in
the methods of assembling joints
7. Backfilling Trenches
If the Contractor allows material to become unsuitable, which when excavated was suitable for re-use,
and it is unsuitable when required for backfilling, he shall run it to spoil and make good by replacing
with suitable material. Where required to meet the specification for testing pipelines, trenches shall be
partially
backfilled to provide anchorage, but joints shall be left exposed. Backfilling shall wherever practicable
be undertaken immediately the specified operations preceding it have been completed. No backfill
material shall be placed in trenches containing water. In trenches in roads, verges and where shown on
the drawings above 300 mm over the crown of the pipe backfill, material shall be deposited in layers
each not exceeding 225 mm thickness and each compacted to 100% with a moisture content between
0.8 and 1.05
The backfill material must not include any stones or boulder of dimensions exceeding 150 mm in any
position. Sufficient space shall be left to receive the original thickness of soil, turf or other materials
removed from the surface. The surfaces shall be restored by replacing the materials in their proper order
and form, and by compacting them to such a level as shall ensure that after settlement is complete the
surface level of refilled trenches shall be within 30 mm of that of the adjacent undisturbed ground.
Where directed, trenches shall be backfilled with lean mix concrete made with 1 kg. cement to 12 kg.
aggregate. The aggregate will be ash, clinker, gravel, stone, or other hard material, approved by the
Architect, and free from sulphates, dust, and other deleterious material.
8. Open Surface Water Channels
Excavation shall be carried out generally as described for pipe work. The invert shall be finished to a
true line and fall and sides shall be trimmed to the slopes indicated. Invert blocks and side slabs shall
be laid on a 100 mm thick bed of suitable approved granular material formed and well compacted. They
shall be joined by thickly covering the joint face with mortar and driving the next unit firmly against
that previously laid. The excess mortar squeezed out of the joint shall be neatly troweled led off.
Channels ends shall be saturated with water and newly completed joints shall be protected and cured as
for concrete
pipes.
43
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 09: ELECTRICAL INSTALLATION AND FIRE SERVICES
General
The contractor shall identify all necessary diversions of the existing building services and notify the
Contract Administrator in writing with proposals, method statements and drawings.
All services diversion associated with the Works shall be carried out by the contractor unless otherwise
stated.
Materials for electrical conduit systems and for cable duct systems shall be stored in accordance with
the manufacturers’ recommendations in a dry and weatherproof store.
Holes and recesses shall be left in structures for electrical installations. If instructed by the Contract
Administrator, holes and recesses shall be cut in structures for electrical installations.
Holes and recesses in internal floors, stairways and platforms shall be protected with temporary covers
or by other methods agreed by the Contract Administrator until the electrical installation starts. Holes
and recesses in roofs, external walls and external floors shall be sealed with watertight temporary covers
until the electrical installation starts.
Holes in structures shall be filled and made good after electrical installations are complete.
Holes left in structural elements designated as fire barriers shall be sealed to at least the same degree of
fire resistance as the structural element.
The tolerance in floor levels for switchgear rooms shall be as follows:
(i) ± 2 mm in 1000 mm for high voltage switchgear rooms,
(ii) ± 4 mm in 1000 mm for medium voltage switchgear rooms.
The tolerance lamp standards shall be within 0.1 degrees of the vertical.
Electrical Conduits and Fittings
Electrical conduits and fittings shall comply with BS 4568:1970 Parts 1 and BS EN 50086- 1:1994 and
shall have Class 4 heavy protection inside and outside. Conduits shall be heavy gauge with screw-end
construction in steel and shall have an external diameter of at least 20 mm. Conduits shall be
longitudinally welded.
Metal boxes for enclosing electrical accessories shall comply with BS 4662:2006+A1:2009 and shall
have heavy protection inside and outside. The boxes shall be of preferred sizes and shall be 35 mm or
47 mm deep as appropriate. Circular ceiling boxes of deep pattern shall comply with BS 4568:Part 2
and shall have Class 4 heavy protection inside and outside. The boxes shall be at least 60 mm deep
internally.
Cables and Duct Fittings
uPVC cable ducts for installation above ground or for casting into concrete shall be Class 0 uPVC pipes
complying with BS 3506. Cable ducts for installation below ground shall be Class B uPVC pipes
complying with BS 3506:1969.
Joints and fittings for use with uPVC cable ducts shall comply with BS 4346:Part 1 and BS 4346:Part
2. Solvent cement for uPVC pipes and fittings shall comply with BS 4346:Part 3.
PVC Insulated Cables
PVC insulated cables shall consist of copper conductors, PVC insulated to C.M.A. Standards and to
B.S. 6004:2000. Cables for three phase and single phase circuit shall be 600/1000 volt grade.
The current carrying capacity shall be in accordance with the Regulations and shall be limited to the
specified voltage drop. Minimum size of copper cables shall be as follows:(i) Lighting - 1.5 mm
(ii) Power - 2.5 mm
44
.
Technical Specifications
_____________________________________________________________________________________________________________
All wiring shall be carried out on the loop-in system and the wires shall be drawn into the conduit after
the whole of this installation has been completed. No joints or connectors will be allowed in any such
cable, except that connectors may be used in accessible position within light fittings.
Color for identification of conductors in fixed electrical installations shall be as shown below:Function
Colour Code
Letter Code
Phase of single phase circuit
Brown
L
Phase 1 of 3-phase circuit
Brown
L1
Phase 2 of 3-phase circuit
Black
L2
Phase 3 of 3-phase circuit
Grey
L3
Neutral
Blue
N
Protective conductor
Green and Yellow
Distribution Board
All distribution board shall contain a main switch.
All wiring, bus-bar etc. within the distribution board shall be adequately shrouded and an insulating
front shield of 3 mm thickness shall be provided to completely screen the distribution unit interior. Only
the MCB, RCCB and MCCB operation dolly and insulated surround shall project through the shield.
Neutral bars shall be of adequate cross section, mounted on insulator, and drilled to receive circuit
wiring. The distribution board shall be completed with circuit record card, suitably roofed and finishes,
giving the total number of points served by each MCB, total load per way and the area served.
The sheet metal for the MCB Board shall be not less than 1.0 mm and 1.5 mm for MCCB Board.
Engraved labels shall be fixed to all MCB, RCCB and MCCB etc., showing the circuit numbers and
purpose.
Engraved labels to identify the purpose of distribution boards shall also be fixed to the panel door/cover.
IP rating for the Distribution Boards shall be submitted to the Contract Administrator prior to installation
for approval.
Earthing System
Provide new electrical bonding for newly installed equipment to existing earthing system to satisfy the
latest statutory obligations, regulations and specifications.
All metal working associated with the electrical installation not forming part of a phase or neutral circuit
shall be bonded together and shall be solidly and effectively earthed.
Pits and trenches for electrical earthing systems shall be excavated at positions and at the times
instructed by the Contract Administrator.
After the electrical earthing systems have been installed fill material shall be deposited and compacted
in the pits and trenches to a depth of 300 mm above the electrical earthing system.
Fill material shall be sand or fine fill material which has been selected from the excavated material, and
which is free of stones retained on a 20 mm BS test sieve. Fill material shall be compacted by hand
rammers in a manner approved by the Contract Administrator.
1. General Provisions for Electrical Works
A. Drawings and general provisions of Contract, including General and special Condition s (General
requirements), apply to work of this section.
B. It’s the Contractor responsibility to be fully aware of and comply with all of the requirements of
the Above.
2. Description of Works
45
.
Technical Specifications
_____________________________________________________________________________________________________________
A. The requirements of the Contract Documents, including the General Conditions and special
Conditions and General Requirements apply to the work of this division.
B. In case of conflict between these requirements and the general requirements, refer the issue to
engineer for direction.
C. Drawings are diagrammatic and are a graphic representation of contract requirements to the best
available standards at the scale required.
D. Light and power and systems riser diagrams and schematic diagrams generally indicate equipment
connections to be used for various systems. Provide system raceway and wiring as required for
actual systems installed on this project. Provide all work shown on diagrams whether or not it is
duplicated on the plans.
E. Specifications include incomplete sentences. Words or phrases such as "the contractor shall,"
"shall be," "furnish," "provide," "a," "an," "the," and "all" have been omitted for brevity.
F. Except where modified by a specific notation to the contrary, the indication and/or description of
any item, in the Drawings of Specification or both, carries with it the instruction to furnish and install
the item complete with all appurtenances or accessories necessary to complete any required system,
regardless of whether or not this instruction is explicitly stated as part of the indication or
description.
G. Specifications, bill of quantities and Drawings are complimentary and are to be taken together for a
complete interpretation of the work.
H. Drawings of necessity utilize symbols and schematic diagrams to indicate various items of work.
Neither of these have any dimensional significance nor do they delineate every item required for the
intended installation.
I. Install the work in accordance with the diagrammatic intent expressed on the electrical and
mechanical drawings, and in conformity with the dimensions indicated on final architectural working
drawings and on equipment shop drawings.
J. Certain details appear on the drawings which are specific with regard to the dimensioning and
positioning of the work. These details are intended only for the purpose of establishing general
feasibility. They do not obviate field coordination for the indicated work.
K. Derive information as to the general construction from structural and architectural drawings and
specifications.
L. Where a discrepancy exists between the drawing and / or between drawings and other parts of the
Contractor Documents or where the interpretation of either is in doubt, the Contractor shall obtain
written clarification from the Engineer on such matters before commencing the Work.
3. Discrepancies Between Drawings
A. Should any differences exist between the drawings or should there be any discrepancy in the
figures, scale or the respects, the Contractor shall refer the same to the Engineer for clarification
before proceeding with the work.
4. Control of Quality
A.
Unless otherwise specified all materials, plant and equipment, and the use and installation
thereof, shall comply with the material, test and other requirements of the relevant. IEE wiring
regulations 16th edition, IEC standards and BS standard.
B.
Materials or substances which are generally known at the time of use to be deleterious shall not
be used other than as allowed by standards or statutory regulation current at the time of use
46
.
Technical Specifications
_____________________________________________________________________________________________________________
C.
D.
F.
Workmanship shall be of the best quality, and shall be produced by skilled and responsible
craftsmen fully experience and in their respective trades.
Allow for proper packing and safe delivery of all equipment and materials and for returning reusable packaging to the suppliers as appropriate E. Include for obtaining materials from any
source whatsoever to complete the works within the contract period and no claim will be
allowed for materials ex-stock or from any other source in the event of difficulty of supply.
Identical parts of similar equipment shall be interchangeable and any items, fittings or
accessories which are used in quantity shall in each case be the produce of one manufacturer.
5. Protection of Material and Equipment Prior to Fixing
A.
All installation materials, component parts or complete items of equipment shall be delivered
and stored on site in properly labeled boxes, crates or containers, suitably designed and
constructed to give protection against transportation and handling damage and deterioration
during storage. The packing shall be weather-proof.
B.
Store all materials on raised boarded platforms under weather-proof cover and store pipes,
conduits, Trunking and the like on racking.
C.
Equipment or component parts of equipment specifically designed to operate in normal room
conditions, shall be delivered to and stored on site with suitable waterproof protection.
D.
Take particular care to protect component parts specifically designed to act as heat transfer
surfaces. These surfaces shall have purpose-designed packing to protect them whilst in transit
and storage on site.
E.
Examine all materials and equipment supplied under this contract on delivery to site and
immediately prior to installation. Any material or equipment which is damaged or faulty shall
be replaced.
6. Protection of New Works
A.
The contractor shall be entirely responsible for ensuring that all his work is adequately
protected. Protection shall be by the contractor at the completion of each day and during
periods of inclement weather, and all work exposed to view on completion in the works shall
be protected from spillage, stains and other damage. All systems shall be kept in a fully
drained condition prior to commissioning.
7. Inspection and Testing
A.
Agree procedures for notices, witnessing, reporting and recording tests with all parties
involved including local authorities and statutory undertakings, prior to the commencement of
the works.
B.
Submit copies of the formal test certificates signed by the contractor's representative not later
than seven days after completion of successful tests.
8. Rejection of Materials or Works Not To Standards of Samples
A.
Any material or work which is inferior to an accepted sample or is different from parts
of the works already constructed or which is stained or damaged after installation will
be treated as defective work.
9. Defective Work
A.
Defective work, and the opening up of the works to ascertain same, shall be dealt with
47
.
Technical Specifications
_____________________________________________________________________________________________________________
B.
C.
strictly in accordance with the requirements detailed elsewhere in the contract document.
Replace defective work with materials, goods or work in accordance with the contract
documents. Alternatively submit proposals for any treatment or making good that is considered
will bring the defective work to the standard required by the contract documents. Such
proposals shall not relieve the contractor of his responsibility to execute the works to the full
intent of the contract documents.
The costs as defined in the contract conditions shall include the cost of any related
delay or disruption in the progress of the works, or any other consequential cost.
10. Existing Site Services
A.
Co-ordinate and co-operate with the Engineer in the location, protection and any necessary
temporary diversion of existing site services.
B.
Make a dimensioned sketch describing the exposed service and locating it in plan and section
to permanent and accessible reference points date and sign the sketch and submit same to the
Engineer.
C.
Any service so exposed shall only be covered up by permanent works with the written
consent of the Engine rakings for same.
11. Temporary Works
A.
All temporary works required for the proper and safe construction of the permanent works
and for the protection of personnel on site.
B.
Advise the Engineer of all temporary works required to be carried out together with all
details of work required to uphold existing services and intended temporary connections
thereto.
12. Connections To Existing Services
A.
All necessary notifications and authorizations in respect of connection of temporary or
permanent connection to existing services or investigator opening up thereof.
B.
No temporary or permanent connection to existing services or investigator opening up
thereof shall be carried out without prior notification to the Engineer and any necessary
authorization obtained from the Engineer.
13. Safety Equipment
A.
The contractor shall provide and maintain in full working order all necessary safety
equipment for access and inspection purposes for use by the contractor and for use by
other personnel on site as instructed by the Engineer. Such equipment shall include, but
not be limited to, protective clothing, safety harness, gas detection and emergency
breathing apparatus for inspection of confined spaces.
14. Testing and Commissioning
A.
The contractor shall be required to demonstrate that the equipment and systems under this
Contract function and operate in full accordance with the Specification and the testing and
commissioning procedures described elsewhere in this Specification.
B.
Once the Contractor has demonstrated the operation of the Works to the satisfaction of the
Engineer the complete integration of the Contractors Works with the Works of others will
be the responsibility of others.
48
.
Technical Specifications
_____________________________________________________________________________________________________________
C.
D.
E.
Notwithstanding this, the Contractor's Works will not be deemed complete until the works
are fully integrated and demonstrated in function and operation as being fully integrated
with the associated works by others.
The Contractor shall allow for full attendance to the Engineer and others in order that the
whole of the Works under this contract can be successfully demonstrated to be functioning
and operating with all other associated works to the satisfaction of the Engineer..
This shall not relieve the contractor in any way of his responsibilities under the Contract.
15. Polyvinyl Chloride Conduit (PVC)
a.
Use for embedded installation , for installation above false ceiling and service
entrance conductors. Provide separate earthing (ground) wire.
b.
Cut ends square, ream smooth, wipe clean, apply approved solvent cement and
quarter turn as drawing up tight in accordance with recommendations of
manufacturer.
c.
Convert to steel conduit using adapters when entering the building from
underground locations.
d.
All conduit joints shall be made in accordance with the manufacture's installation
recommendations using a solvent adhesive recommended by the maker of the
conduit. All such joints shall be watertight.
The same conditions shall apply to joints between conduit, fittings and
accessories. The dipping of conduit or fittings into solvent adhesives is expressly
forbidden. Before joints are made, conduit ends shall be cut square and all
burrs and sharp edges shall be removed. Care should be taken to remove all
damp, grease, cement dust and oil from all faces of conduits and accessories
prior to joining. Conduits shall be entered fully into box spouts and butted into
couplers, other than expansion couplers, for jointing purposes.
e.
Screwed PVC conduit shall not be used unless specifically called for on the
drawings or when the PVC conduit is to be connected to metal equipment,
conduit and fittings with screwed entries. Where such entries are not available,
non-screwed male bushes and couplers shall be used.
f.
Where conduit crosses building expansion joints or where there are changes of
temperature in excess of 25oC, flexibility of the conduit to cope with the
associated movement shall be achieved by a method approved by the
manufacturer of the conduit.
g.
All bends shall be made using the correct size spring. Conduit sizes of 25 mm
and below may be set cold but all larger sizes shall be set hot. A pipe vice shall
not be used during this or any other operation. The radius of any conduit bend
shall not be less than 4 time the outside diameter of the conduit. Naked flames
shall not be used directly to heat conduit for bending purposes. The use of
conduit bends having factures and conduits with any wrinkles on formed bends is
not permitted.
h.
Different colors shall be applied for conduits of different systems.
16. Field Quality Control
Upon completion of installation of raceways, perform continuity tests by testing the resistance
of all feeder conduits from the service to the point of their final distribution using 1 conductor
49
.
Technical Specifications
_____________________________________________________________________________________________________________
return. Limit the maximum resistance to 25 ohms. When possible, field-correct malfunctioning
equipment, then retest to demonstrate compliance. Replace equipment which cannot be
satisfactorily corrected, at no additional cost to the Owner.
17. Inspection of Works
The Contractor shall allow the Contract Administrator to inspect the following work for electrical
installations:
(i) Completed concealed electrical conduit systems, cable duct systems, electrical earthing systems and
items and equipment which are to be grouted or covered up, (ii) Items and equipment which are to be
tested, and (iii) Structures that are to be made available for electrical installations.
The Contractor shall inform the Contract Administrator three days, or such shorter period agreed by the
Contract Administrator, before work is covered up, tested or made available.
18. Testing
Concealed electrical conduit systems shall be tested to determine the earthing continuity. The system
shall be tested:
(i) Before the system is cast in concrete or covered up,
(ii) After the system is cast in concrete or covered up, and
(iii) After electrical wiring that is installed by the Contractor is complete.
The Contractor shall carry out all the inspection and test listed below but not limited to the following:
(i) Visual inspection of low voltage installation.
(ii) Continuity of right final circuit conductors test.
(iii) Continuity of protective conductors tests, including main and supplementary equipotential bonding
test.
(iv) Insulation resistance test.
(v) Polarity test.
(vi) Earth fault loop impedance test.
(vii) Functions of all protective devices test.
(viii) Functions of all items of equipment test.
19. Fire Services and Emergency Installations
General
All materials, and equipment to be incorporated in the Fire Services Installation at the Contractor’s
works, shall comply with the requirements of this Section. These requirements shall be minimum
requirements for general purposes and they shall not relieve the Contractor from ensuring that his
designs are sound, and that all materials and equipment incorporated in the works are suitable for their
intended purposes and environment.
No substitutions to these standards will be permitted without the endorsement of the Contract
Administrator.
Emergency Lighting
Emergency lighting for fire escape purpose shall comply with BS 5266-1:2005.
Emergency lighting shall be backed up by emergency power supply.
In the event of power failure, the emergency lighting shall be activated within 5 seconds or within such
shorter time specified elsewhere in the Specification upon mains power failure. To meet this
requirement, emergency lighting shall be provided with secondary battery supply, uninterrupted power
50
.
Technical Specifications
_____________________________________________________________________________________________________________
supply, or an approved source of backup power supply accepted by the Contract Administrator even
when they are connected to the emergency generator.
Exit Sign
Exit sign shall conform to BS 5499-1:2002, BS 5499-4:2000, unless otherwise specified. Exit sign shall
also comply with the requirements in the Local Building Code. The provision of exit sign shall deem to
include all related directional signs or series of signs for the exit routes as specified in progression
towards the exit as indicated by the exit sign.
To ensure the visibility and conspicuousness of the exit sign at all times including fire and smoke
conditions, exit signs shall conform to all the following requirements as the minimum: (i) Exit signs shall be internally illuminated bearing the words “EXIT” in block letters and characters of
not less than 125mm high with 15mm wide strokes. Color contrast for translucent surrounds to lettering
shall be either one of the following combinations or as specified: Color
Contrasting Color
Green
White
White
Green
(ii) The color combination selected shall be consistent throughout the same building. The color shall not
deteriorate or become faint throughout the service life and lasts for at least ten years.
(iii) The viewing distance of exit sign shall be not less than 25 m under ambient no smoke condition
with and without normal lighting. The words shall be easily legible. Uniformity of luminance is the
critical factor. The ratio of the maximum to the minimum luminance within either white or green color
area shall be not greater than 10:1.
(iv) The exit sign shall be easily visible and conspicuous in fire and smoke conditions. The viewing
distance shall not be greatly reduced in the presence of smoke. Brightness of exit sign is the critical
factor for visibility in fire and smoke conditions. The exit sign shall produce an average luminance of
not less than 100 cd/m2 unless otherwise specified. The ratio of the luminance at white area of the exit
sign to the luminance at green area shall be not less than 5:1 and not greater than 15:1. The electrical
supply for exit signs and directional signs shall be provided under the electrical work but connection to
the exit sign shall be under Fire Service work.
The exit sign and directional signs shall be of the self-contained and maintained emergency type.
Weatherproof type shall be used in outdoor application.
Fire Extinguishers
Fire extinguishers shall be rechargeable hand-operated extinguishers complying, BS 5306-3:2009 and
BS 7863:2009 for water, foam, dry powder, carbon dioxide, NASF III, FM200 or other approved agent
type with a capacity as specified.
Fire extinguishers shall be manufactured and tested to recognized international standards.
Portable fire extinguisher shall be constructed with aluminum alloy, anodized for corrosion protections
and equipped with solid brass operating head fitted with a brass discharge nozzle and piercing spindle
connected by a stainless steel spring to a chrome-plated brass operating handle.
Fire extinguisher shall be operable to -40°C.
A sturdy wall hanger shall be provided for proper fixing of fire extinguisher.
The necessary operation, maintenance and re-loading instructions (including capacity, due date of
annual inspection, types of fire suitable, gross and net weight) shall be clearly displayed permanently
on the extinguisher body.
Smoke Detector
Smoke detector shall be of proprietary design to avoid false fire alarms. The Contractor shall supply and
install smoke detectors that have good track record or job reference on no false fire alarm.
51
.
Technical Specifications
_____________________________________________________________________________________________________________
Smoke detector shall function correctly at continuous ambient temperature between 0oC and 48oC,
relative humidity up to 99% continuous non-condensing in non-air-conditioned space and relatively
humidity up to 95% continuous non-condensing in air-conditioned space unless otherwise specified.
Smoke detector shall be housed in a corrosion-proof plug-in unit designed to mount pendent, surface or
semi-recessed as specified. Sensitivity shall be adjustable by means of a pre-set control only accessible
by use of a special tool or in the central fire alarm control system.
Smoke detector installed inside lift shaft and outdoors shall be completed with extra wind-shield to cater
for higher air current and shall also be of harsh type with anti-condensation facilities designed for higher
temperature fluctuation, relative humidity and dirt accumulation.
Smoke detector shall have normal working life (mean failure time) of not less than 10 years.
Break Glass Unit
Break glass unit shall comply with BS 54-11:2001.
Break glass unit shall have at least 2 pairs of normal-open (NO) contacts, and one pair of normal-close
(NC) contact.
The NO contacts shall close and NC contacts shall open immediately when the front glass is smashed.
The unit shall be of pleasing appearance and styling, constructed of non-corrodible materials and
finished enamel red. The words “In case of fire, Break Glass” shall be engraved or embossed on the
front in English.
The unit shall be suitable for 24V D.C. operation. The contacts shall be of silver or approved nondeteriorating alloy.
The breaking of the glass shall not release an alarm. The glass plate shall be designed in a way to prevent
injuries when struck by the personnel. The pushing of the call button will initiate an alarm.
The unit shall be possible to test without breaking the glass by use of a special tool.
Generally, the unit shall be fixed at a height of 1.15 m above finished floor level unless otherwise
required to comply with the universal accessibility best practices. They shall be surface mounted, or
semi-recessed, in order to present a side profile area of not less than 750 mm2.
The unit shall be provided at all escape routes and in particular at each hose reel point, all storey exits
and all exits to open air.
Manual call points shall be of addressable type when analogue addressable manual and automatic fire
alarm system is provided.
Alarm Bell
Alarm bells shall be of minimum 150 mm diameter gong suitable for 24 V DC operations. They shall
comply with BS 5839-1:2002.
The bell shall consist of a micro motor as the driving unit offering high performance and reliability
together with low current consumption and low starting voltage characteristics.
The bells shall be painted red and labeled “FIRE ALARM” in both English.
The alarm bells shall produce an alarm sound level complying with BS 5839-1:2002 in all accessible
parts of the buildings when the doors of the rooms are closed.
The alarm bells shall be sited and distributed throughout the buildings to produce the alarm sound level.
52
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 10 – INSITU FINISHES
Screeds
1. Preparation
Suitability of Bases: Before starting work ensure that;
 Bases are sufficiently flat to permit specified levels and flatness of finished surfaces, bearing in
mind the permissible minimum and maximum thickness of the screed / topping.
 Concrete slabs have been allowed to dry out by exposure to the air for not less than 6 weeks.
 Bases are clean and free from plaster, dirt, dust and oil.
2. Bonded Construction
Shortly before laying screed completely remove mortar matrix from surface to expose coarse aggregate
over entire area of hardened base slab using abrasive blasting or, for in-situ slabs only, pneumatic
scrabbling. Remove all dust and debris. Keep base slab well wetted for several hours before laying
screed/topping.
3. Finishing/ Curing
Smooth Floated Finished: Use a hand float, skip float or power float to give an even surface with no
ridges or steps.
4. Trowelled Finish:
To receive applied floor finishes:
Float to an even surface with no ridges or steps. Hand or power trowel to give a uniform smooth but
not polished surface free from trowel marks and other blemishes and suitable to receive the specified
flooring materials.
Plastering
5. Application Generally:
Apply each coating firmly to achieve good adhesion and in one continuous operation between angles
and joints.
All coatings to be not less than the thickness specified, firmly bonded, of even and consistent
appearance, free from rippling, hollows, ridges, cracks and crazing. Finish surfaces to a true plane, to
correct line and level, with all angles and corners to a right angle unless specified otherwise, and with
walls and reveals plumb and square. Prevent excessively rapid or localized drying out.
6. Dubbing Out:
If necessary to correct in accuracies, dub out in thickness of not more than 10mm in same mix as first
coat. Allow each coat to set before the next is applied. Cross scratch surface of each dubbing out coat
immediately after set.
7. Smooth Finish:
Trowel or float to produce a tight, matt, smooth surface with no hollows, abrupt changes of level or
trowel marks. Do not use water brush and avoid excessive trowelling and over polishing.
53
.
Technical Specifications
_____________________________________________________________________________________________________________
8. Wood Float Finish:
Finish with a dry wood float as soon as wet sheen has disappeared from surface to give an even overall
texture.
Floor Tiles
9. Ceramic Floor Tiles
Ceramic floor tiles including corresponding accessories, shall be in accordance with BS 6431.
Ceramic floor tiles shall be Group A I or B I: water absorption not exceeding 3%.
Floor quarries shall be Group A IIb of BS 6431: water absorption of 6% < E =< 10%.
Where ceramic floor tiles or clay floor quarries are described as “including specials”, the full range of
BS fittings shall be required. Elsewhere mitred angles of coved skirtings and the like shall be permitted.
All tiles and fittings shall be from the same manufacturer and shall match in colour and texture.
Where tiles are described as anti-slip, they shall be suitably embossed or treated with carborundum or
similar grit to comply with relevant standards, e.g. Germany DIN standard or other recognized
international standards to provide an anti-slip surface.
10. Laying Floor Tiles
Floor tiles shall be fixed as follows:
(i) Using semi dry method direct to concrete base:
(a) Soak tiles in clean water and allow to drain.
(b) Lay semi-dry mix cement and sand 1:4 bed thoroughly compacted to the required
thickness (20 mm minimum) finished to the required levels, falls and currents.
(c) Pour cement and sand slurry over bedding and spread and trowel to 3 mm (minimum)
thick.
(d) Lay tiles, mixed from six boxes, and tamp firmly into bed with straight and even joints
and 3 mm (minimum) wide.
(e) Allow bedding to set.
(f) Grout up joints and clean surplus grout face of tiles as work proceeds.
11. Expansion Joints
Expansion shall be allowed with a 75 mm space around perimeter and 25 mm joints per 9 m2 cut through
joints and filled with cold bitumen or approved sealant.
54
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 11: PAINTING
General
All paints and decorative materials shall be of approved type, brand and color.
Selection of Colors
The colors of paintwork shall be provisionally selected by the Contract Administrator from a catalogue
showing the range of colors offered by the manufacturers.
Trial panels shall be painted in each of the colors provisionally selected by the Contract Administrator.
Each trial panel shall be 1 m x 1 m and shall be painted with the complete paintwork system.
Trial panels shall be protected from damage and shall be left in position until the Contract Administrator
instructs their removal.
Storage of Paints
Paint and associated materials shall be stored in a dry weatherproof and covered store. The store shall
be maintained in a cool and well-ventilated condition.
Tins of paint shall be labelled as being for external use, internal use, undercoating and finishing, as
appropriate, and shall be protected from exposure to conditions that may adversely affect the material.
Paint and associated materials shall be stored in accordance with the manufacturers’ recommendations
and shall not be used after the recommended shelf life has been exceeded.
No smoking shall be permitted where flammable paints or solvents are used. Appropriate signs should
be displayed at conspicuous place as appropriate.
Primers
For synthetic finishing paints on internal and external woodwork, aluminum primer to BS 4756:1988,
Type 1 shall be used.
For synthetic finishing paints on internal and external metalwork, zinc phosphate primer or metallic
zinc-rich primer to BS 4652:1995 Type 2, as specified shall be used.
For synthetic or non-toxic paints on galvanized metal surfaces, an approved etching primer with a zincchromate base shall be used.
Sealers
For plaster, masonry and the like, sealers shall be an approved stabilizing solution or oil-based plaster
sealer.
Emulsion paint
Emulsion paint shall be acrylic, plastic, vinyl or latex emulsions and shall be approved material by
Contract Administrator.
Textured paint
Textured emulsion paint shall be acrylic based emulsion paint textured with a finely dispersed aggregate
approved by the Contract Administrator.
External textured paint shall be an approved heavy duty masonry paint incorporating fine aggregate
filler.
Anti -moulds Liquid
Anti-moulds liquid shall be an approved fungicidal solution.
Water Repellant Liquid
Water repellent liquid shall be silicone or other approved water repellent.
Polyurethane paint
Polyurethane paint shall be of the Two Pack Type and part of an approved system.
Wood preservative
55
.
Technical Specifications
_____________________________________________________________________________________________________________
Wood preservative shall offer complete protection against termites, wood boring insects, fungi, wood
rot and decay. It shall be an approved proprietary brand exterior grade, where completely concealed or
not decorated, and colorless, colored or suitable for overpainting where likely to be exposed or be in
contact with a painted finish.
Varnish
Varnish shall be one of the following types:
(i) Copal Varnish shall be No. 1 Extra Pale quality for internal use only.
(ii) Synthetic Varnish shall be the Long Linseed Oil Alkyd type for internal or external use.
(iii) Polyurethane Varnish for internal or external use shall be either:
(a) Moisture Cure Oil Modified
1. Notice
Give sufficient notice so that inspection may be made of the substrate immediately before application
of paint finishes.
2. Clear finish coated samples
Submit pieces of timber or timber veneer matching the timber to be used in the works, prepared and
coated in accordance with the paint system.
3. Opaque coated samples
Provide approx. 600x600mm samples on representative substrates of each paint system showing
surface preparation, color, gloss level and texture.
4. Combinations
Do not combine paints from different manufacturers in a paint system.
Clear timber finish systems: Provide only the combinations of putty, stain and sealer recommended by
the manufacturer of the top coats.
5. Delivery
Deliver paints to the site in the manufacturer’s labelled and unopened containers.
6. Tinting
Provide only products which are color tinted by the manufacturer or supplier.
7. Putty
Non-timber substrates: Oil-based or polymeric based.
Timber finishes: Lacquer or water based only.
8. Order of work
Other trades: Before painting, complete the work of other trades as far as practicable within the area to
be painted, except for installation of fittings and laying flooring materials.
Clear finishes: Complete clear timber finishes before commencing opaque paint finishes in the same
area.
9. Protection
56
.
Technical Specifications
_____________________________________________________________________________________________________________
Fixtures: Remove door furniture, switch plates, light fittings and other fixtures before starting to paint,
and refit in position undamaged on completion of the installation.
Adjacent surfaces: Protect adjacent finished surfaces liable to damage from painting operations.
10. “Wet paint” warning
Place notices conspicuously and do not remove them until paint is dry.
11. Restoration
Clean off marks, paint spots and stains progressively and restore damaged surfaces to their original
condition. Touch up damaged decorative paintwork or misses only with the paint batch used in the
original application.
12. Drying
Ensure that the moisture content of the substrate is at or below the recommended maximum level for
the type of paint and the substrate material.
13. Paint application
Apply the first coat immediately after substrate preparation and before contamination of the substrate
can occur. Apply subsequent coats after the manufacturer’s recommended drying period has elapsed.
14. Priming before fixing
Apply one coat of wood primer (2 coats to end grain) to the back of the following before fixing in
position:
- Timber door and window frames.
- Bottoms of external doors.
- Associated trims and glazing beads.
15. Spraying
If the paint application is by spraying, use conventional or airless equipment which does the
following:
- Satisfactorily atomizes the paint being applied.
- Does not require the paint to be thinned beyond the maximum amount recommended by the
manufacturer.
- Does not introduce oil, water or other contaminants into the applied paint.
16. Sanding
Clear finishes: Sand the sealer using the finest possible abrasive and avoid cutting through the colour.
Take special care with round surfaces and edges.
17. Paint system description
Choose from the following paint systems and substrates and paint in accordance with manufacturers
recommendations:
18. Paint Systems:
Flat water based: Interior
57
.
Technical Specifications
_____________________________________________________________________________________________________________
Low gloss water based: Interior
Flat or low gloss water based: Exterior
Semi-gloss water based: Interior
Semi-gloss water based: Exterior
Gloss water based: Interior
Gloss water based: Exterior
Semi-gloss, oil based: Interior
Full gloss, oil based: Interior
Full gloss, oil based: Exterior
Texture finish, water based: Interior
Texture finish, water based: Exterior
Varnish clear: Interior
Varnish tinted: Interior
Opaque timber finish, water based: Exterior
Paving paint - Semi gloss oil based
Roofing paint, oil based
Low flame spread specialized coating
19. Number of coats
Unless specified as one coat or two coat systems, each paint system consists of at least 3 coats.
20. Color selection
As nominated in the Drawings or as approved by the Engineer.
58
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 12: EXTERNAL WORKS
ROADS, WALKWAYS, CAR PARK, APRON AND PAVED AREAS
1. In-situ Concrete Paving
In-situ concrete paving, channels and kerbs shall be constructed, if so specified, in accordance with
Section of Concrete for Minor Work and Concrete Repair
2. Surface Dressing
Surface dressing aggregate shall comply with BS EN 13043:2002 of 3 or 6 mm nominal size.
3. Preparation of Surface
Surfaces on which materials to be laid shall be brushed repeatedly free from standing water, loose
material and dust.
4. Regulating Course
When specified, a regulating course shall be laid and compacted to the required levels and profiles.
5. Machine Laying
The base and wearing course shall be laid by means of an approved self-propelled paving machine. The
paving machine shall produce a smooth uniform surface texture free from segregation, shoving or drag
marks. A fully trained and experienced operator shall be in direct charge of the machine at all times.
6. Compaction
Compaction shall be commenced as soon as the material will bear the weight of the roller. Roll in a
longitudinal direction only, each successive pass overlapping the last by at least a half width of the rear
roller. Rollers shall not stand on newly laid material. Compact the base and wearing course so that air
voids in the mixture are between 3 and 5% when measured
7. Hand Laying and Consolidation
Hand operated mechanical compaction plant laying and consolidation by means of an approved
mechanical tamper shall be permitted for work executed in patching-in repairs, reinstating surfaces over
excavated trenches, surfacing areas inaccessible to the paving machine or roller, and surfacing areas
which in the opinion of the Contract Administrator, are too small to warrant the use of a paving machine
and roller.
8. Clearing Off
After surfacing or dressing has been executed, all channels, kerbs, manhole covers, gratings, etc. shall
be cleared and cleaned free of all excess materials.
STEEL FENCE POSTS AND GATES
9. Fencing General
Fencing shall be erected to the lines and levels indicated on the drawings. Fencing shall be erected to a
smooth alignment with no abrupt irregularities. The ground shall be trimmed or filled in such a manner
59
.
Technical Specifications
_____________________________________________________________________________________________________________
that the bottom of the fence will approximately follow the level of the ground. The distance between the
bottom of chain link mesh and hoarding and the ground shall not exceed 100 mm.
10. Fencing Wire
Line wire, chain link mesh and barbed wire for fencing shall be strained tightly between straining posts.
Winding brackets shall be used for straining between steel posts. The tension in the wire on each side
of straining posts shall be equal. Wire shall be strained until at least 14 days after concrete has been
placed in the foundation.
SEPTIC TANK AND SOAKAWAY
11. Septic Tank and Soak away
Any septic tank constructed or installed in the city shall meet the following minimum specifications:
The tank shall have an inside depth of at least five feet, with a liquid depth of at least four feet.
The length of the tank shall not exceed three times the width, and shall have a liquid capacity of not less than nine
hundred sixty gallons.
The tank shall have at least two compartments, and a manhole of adequate size shall be installed in each
compartment.
The inlet and outlet of the tank shall have a vertical four-inch tee extending two feet below and six inches above
the liquid level of the tank.
The tank shall be watertight, and shall be constructed of concrete, concrete block, brick or tile.
The top of the tank shall be constructed of reinforced concrete, at least four inches thick.
When the tank is constructed of concrete, the walls and bottom shall be at least six inches thick and shall be
adequately reinforced with steel or other approved material.
The concrete used for the tanks shall contain one part cement, two parts sharp sand and four parts crushed rock
or gravel.
Where brick, concrete block or tile is used in the construction of the tank, the inside shall be plastered with
Portland cement mortar, composed of one part cement and three parts sand.
The side walls of the tank shall be adequately reinforced with steel or other approved material so as to withstand
any inside or outside pressure.
A soak away pit constructed not more than 3m away from septic tank and not exceed 2m deep filled with selected
laterite hardcore.
60
.
Technical Specifications
_____________________________________________________________________________________________________________
SECTION 13: ENVIRONEMENTAL AND HEALTH &SAFETY MANAGEMENT
Environmental Guidelines and Code of Conducts
1. General
In general contractor is supposed to refer to the Environmental Management System (EMS) and Health
& Safety (H&S) handbooks (See www.unops.org).
All works shall be conducted in an environmentally and socially sensitive and responsible manner.
The following guidelines are intended to ensure that all parties involved are aware of the potential
impacts of their activities and carry out the work in a manner that is environmentally sensitive as well
as sensitive to the interests and rights of the hospital environment.
The guidelines and code of conduct are designed as a written statement of intent for contractors to adhere
to, and to which recourse can be made in the event of perceived undesired impact. They should therefore
be read and constructed as part of this contract for drilling. The contractor shall be required to familiarize
all employees with the content and spirit of these guidelines.
The contractor shall be required to strictly adhere to these guidelines and code of conduct, failing which
the contractor shall be required to repair any damage resulting from such failure at his/her own cost.
There shall be no time limit on when a contractor can be called back to a site to clean it up.
The Contract is required to submit an environmental management plan that comply with prescription of
the Handbook issued by UNOPS (see link above)
2. Clearing of Vegetation
Clearing of vegetation where applicable should be undertaken using hand tools, save in circumstances
when it is necessary to use mechanical clearing equipment. Approval will be given by the UNOPS
Engineer/Supervisor.
The clearing of vegetation using vehicles or heavy equipment such as bulldozers and tractors, shall not
be allowed unless approved by UNOPS Engineer/Supervisor.
Large trees, with a stem diameter of 200 millimeters (mm) or more, shall not be cut, cutline’s and access
routes (vehicle tracks) should be routed around them.
Where this may not be possible, these trees can only be removed with the express permission of the
hospital management.
3. Site Offices and Storage facilities
If and where site offices and storage facilities are needed, their construction and removal should
be carried out along the following lines:
• Permission from the hospital management must be obtained.
• Access roads to site offices and storage facilities should be sited in such a way to cause
minimum disturbance to the hospital staff, patient, and visitors.
• No permanent structures should be built.
• The site offices and storage facilities is to be removed, site cleared and all scrap removed
at the end of each project.
• All rubbish should be remove and properly dispose of in stipulated dump site.
• Waste oils, chemicals, and mechanical waste to be stored and removed to
government/council designated dumping sites or recycling plants if applicable.
• A proper sanitary facilities should be put in place during construction.
• Fuel, oil or any other chemical substances should be stored properly at the site offices
and storage facilities, with appropriate spill proof containers with adequate spill
61
.
Technical Specifications
_____________________________________________________________________________________________________________
containment, to prevent these substances entering into the environment. Hazardous
substances should be stored in a safe place.
4. Human Relations
All conflicts/disagreements (use of borehole etc.) no matter how trivial must be logged and dated, with
details of the persons involved and subject matter, in a site book for this purpose at the contractor’s site
offices and storage facilities.
5. Construction and Rehabilitation Sites
Each site must be completely cleared of waste after use.
Wastes (chippings, mud, excavated materials etc.) should be buried at a depth of 1 meter. Rubbish,
waste oils, and chemicals should be returned to the main camp for disposal as outlined above.
Drill sites must be checked and signed off as satisfactory by the UNOPS Engineer/Supervisor failing
which the contractor is liable to go back to the site after demobilization to clean it up at his own cost.
6. Disposal of Rubbish
Rubbish shall not be burnt, buried or left on or adjacent to the site during operations or after the field
camp has been dismantled and removed.
7. Noise Levels
The contractor has to ensure that noise levels are minimized and do not unnecessarily disturb
persons or wildlife.
62