SECTION 10
BUILDING SPECIFICATIONS
10.1
10.1.1
CONCRETE
Tolerance
Floor and roof slabs shall be level to a point within ± 5 mm of the level shown on
the drawings. Columns and beams shall have no irregularities exceeding 3 mm
in a 3m length. The position of the face of columns, beams and walls at any point
shall be within 5 mm of its position derived from the drawings.
10.1.2
Concrete Finish
All exposed concrete beams, columns and slab surface described as fair-faced
shall be Type f.f. as follows:Type f.f. shall be an as struck finish entirely free from honeycombing, stains,
pins, clippings, lining joint marks, nail and screw marks, raised grain marks, air
holes and surface defects and shall be uniform in colour tone and surface texture
with clean true faces and arises.
10.1.3
Construction Bays
The Contractor shall submit to the Engineer for his approval prior to concreting
his proposals for the sequence of placing concrete and the position of horizontal
and vertical construction joints.
10.1.4
Small Precast Items
Small precast items such as lintels, sills and padstones shall be built in as the
work proceeds and have a fair-faced Type f.f. finish where exposed to view and
hacked surfaces where plastered.
Lintels shall have a minimum bearing of 100 mm or larger if indicated on the
drawings and shall have inserts for fixing windows and/or doors cast-in.
Sills shall be weathered and have a throat as described, if projecting, and shall
have inserts for fixing windows and/or doors cast-in.
10.1.5
Cast-in Fixings
Cast-in fixings shall be securely fixed to formwork ready for casting and shall be
true to line in the positions shown on the drawings.
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SECTION 10
BUILDING SPECIFICATIONS
10.1.6
Timber Cast-in Fixings
Timber cast-in fixings shall be made from 38 mm x 38 mm dovetailed shaped
softwood battens pressure impregnated with preservative.
10.2
BRICKWORK AND BLOCKWORK
10.2.1
Damp-Proof Course
Horizontal and vertical damp-proof courses shall be hessian based lead cored
bituminous damp-proof course weighing not less than 4.4 kg/m2 to accepted
standards and approved by the Engineer.
Horizontal damp-proof courses shall be laid on an even level bed of fresh mortar
and shall be lapped for the full width of the sheet at corners and junctions.
Stepped damp-proof courses shall be wide enough to be built in to both skins of
the wall and to cross the cavity in one piece.
Vertical damp-proof courses shall be continuous and shall be the width of the
block closing the reveal.
Damp-proof courses shall not be bridged with mortar.
10.2.2
Wall Ties
Wall ties shall be 18/8 stainless steel vertical twist type 200 mm long.
Wall ties shall be built in the mortar beds as the work proceeds and shall be
spaced at a maximum of 900 mm horizontally and 450 mm vertically and shall be
staggered. Each door and window opening shall have wall ties at each joint at 225
mm centres vertically.
10.2.3
Door and Window Frame Ties
As described for Joinery Fixing Accessories. Door and window frame ties shall
be fixed as described under Joinery Work.
10.2.4
Mastic
Mastic for pointing door and window frames shall be one part gun-grade
polysulphide mastic to accepted standards and approved by the Engineer.
10/2
SECTION 10
BUILDING SPECIFICATIONS
Mastic seals to windows or door frames shall be neatly gun applied to clean, solid
and dry backgrounds in one operation. The mastic shall be a triangular seal across
the whole joint and any surplus shall be cleaned off when set.
10.2.5
Brickwork and Blockwork
Brickwork and blockwork shall be as specified in Section 5.
10.2.6
Cement Mortar
Cement Mortar shall be as specified in Section 5.
10.2.7
Pointing
All pointing shall be done as the work proceeds and shall be flush with face of
blockwork.
10.2.8
Hollow Walls
Hollow walls shall be constructed with an outer skin of blockwork and an inner
skin of blockwork leaving a cavity of the widths shown. The two walls shall be
tied together with wall ties as described and the cavity shall be kept and left clear
of all droppings. Openings shall be left at intervals in the blockwork at the bottom
of the cavities and all debris shall be cleared out and the openings bricked up on
completion. Cavities shall be closed at opening reveals with either brick or block
to match the surrounding material and a continuous vertical damp-proof course
shall be built in.
10.3
ROOFING
10.3.1
Roof Screed
Roof screed shall be laid to fall over the concrete roof slab and have a minimum
thickness of 35 mm and maximum thickness of 75 mm. The screed shall be
thoroughly mixed 1:4 cement/sharp sand mix with very little water added. The
screed shall be laid and compacted and shall be levelled off and finished with a
steel trowel. Precautions must be taken to prevent rapid or excessive drying out.
10.3.2
Roof Primer
Primer for concrete shall be suitable for use with the waterproofing membrane
and shall be applied in accordance with the manufacturer's instructions.
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SECTION 10
BUILDING SPECIFICATIONS
10.3.3
Waterproofing Membrane
Flexible waterproofing membrane for roofing shall be bitumen based to accepted
standards and approved by the Engineer.
Surfaces to receive the membrane shall be smooth, dry and free from dust. The
membrane shall be laid on a primed surface and in accordance with the
manufacturer's recommendations.
10.3.4
Roof Insulation
Roof insulation shall be 75 mm thick closed cell non-absorbent rigid polystyrene
insulation board. The insulation boards shall be placed immediately after the
membrane has been laid.
10.3.5
Roof Surface
Roof surface shall be 50 mm thick 450 mm x 450 mm precast concrete paving
slabs laid dry.
10.3.6
Roof Decking
The roof decking shall be aluminium profiled sandwich sheeting fixed to Metsec
‘Z’ section purlins all in accordance with the manufacturer’s instructions. The
Contractor shall provide working drawings and manufacturer’s literature for
approval before ordering the same.
10.3.7
Fascia Cladding
The fascia cladding shall be of single skin construction formed from profiled
aluminium sheeting with matching aluminium profiled flashings. The Contractor
shall provide working drawings and manufacturer’s literature for approval before
ordering the same.
10.4
JOINERY
10.4.1
Timber-General
Timber for joinery shall be air dried and the moisture content be allowed to
reduce until it reaches a level in equilibrium with local conditions. It will be
deemed to have reached equilibrium when the moisture content is 12% + 2%.
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SECTION 10
BUILDING SPECIFICATIONS
10.4.2
Timber Sizes
Timber shall be 3 mm less per wrought or finished face than the sawn size.
10.4.3
Hardwood
Hardwood for joinery shall be sound, well conditioned
and seasoned Mahogany
3
or Meranti with an average density of 529 Kg/m and a moisture content of 12% +
2%. Exposed surfaces of joinery shall comply with the following requirements.
Knots
Checks & Shakes
:
:
Pitch Pockets
Plugs and Inserts
:
:
Pin knots up to 6 mm diameter will be permitted.
Checks up to 3 mm width and 300 mm long will be
permitted.
Not permitted unless cut out and filled.
Not permitted.
Joints and Lamination
Glue Lines
Rate of Growth
:
:
Slope of Grain
:
Species & Character :
Pinholes
:
Not permitted.
Not fewer that 8 growth rings per 25 mm at any
point on any cross section.
Not greater than 1 in 8.
Same on all surfaces and matched as far as possible.
Permitted if filled.
A sample of each representative section for use in the work shall be previously
submitted for approval by the Engineer's Representative.
10.4.4
Timber Fixing Accessories
Nails for fixing joinery shall be aluminium or sheradised mild steel.
Screws for fixing joinery shall be sheradised mild steel.
Bolts shall be stainless steel.
Adhesives for exterior use shall be synthetic resin types, weather and boil-proof,
complying with the approved standard. Adhesives for interior use shall be
synthetic resin types, moisture resistant and moderately weather resistant,
complying with the approved standard.
10/5
SECTION 10
BUILDING SPECIFICATIONS
Door frame and lining fixing cramps shall be of 25 mm wide x 14 swg thick x 250
mm girth stainless steel, one end turned up 50 mm and twice drilled and the end
fishtailed for building-in.
Dowels for fixing door frames shall be 10 mm dia. x 100 mm long stainless steel.
10.4.5
Timber Preservative
Timber preservative shall be water repellent and protect the timber from all wood
destroying fungi and insects particularly termites. The preservative shall be
applied in accordance with the manufacturer's instructions including treatment to
all ends, notches and joints in treated timber out on site.
10.4.6
Ironmongery
Ironmongery shall be as shown on the drawings.
10.4.7
Workmanship
All exposed faces of joiners work shall have wrought faces.
All arises shall be rounded to a 1.5 mm minimum radius unless specified or drawn
to a greater radius.
Where the term 'framing or framed' is used it shall mean all halvings, dovetails,
tenons and hardwood pins and the best known means of putting this work
together.
10.4.8
Storage
All joinery shall be protected from the weather during transit and shall be stored
under cover, clear of the ground in clean, dry ventilated conditions so as to
maintain the specified moisture content.
All framework shall be put together loosely and stored as described and shall not
be wedged and glued together until required for fixing.
10.4.9
Door Frames
External door frames shall be built-in as work proceeds with fixing cramps as
described. The fixing cramps shall be screwed to the back of the frames at 450
mm maximum centres with two sheradised screws 25 mm long. The fishtail ends
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SECTION 10
BUILDING SPECIFICATIONS
shall be built-in to the brickwork or blockwork mortar joints as the work
proceeds.
10.4.10
Doors
External doors shall be hung on one and a half pairs of hinges unless otherwise
detailed, to give a maximum tolerance all round of 2 mm.
10.5
METALWORK
10.5.1
Aluminium
Aluminium alloy sections for aluminium shall be type H59 TF box sections.
10.5.2
Aluminium Louvers
Aluminium louvers shall be made from NS 4 H3 aluminium and have a natural or
bronze anodised finish. Sizes to be as shown on the drawings.
10.5.3
Aluminium Windows
Aluminium windows shall be manufactured by an approved specialist window
manufacturer from extruded aluminium sections mechanically cleated and sealed.
Glazing to be fixed into opening with clip on aluminium beads and gasket sealed.
Finish to windows to be natural anodised 25 microns in thickness. Windows are
to be fixed into openings with stainless steel screws and sealed all round in mastic
bedding.
10.5.4
Ironmongery
Rates for supplying and fixing ironmongery shall include for all boring, cutting,
mortising, sinking, making good, replacing damaged screws, oiling, adjusting,
leaving in good working order and mastering all locks.
Screws shall be of suitable gauge and material for the purpose and shall match the
item to be fixed.
10.6
PLUMBING
10.6.1
Copper Tubes
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SECTION 10
BUILDING SPECIFICATIONS
Copper tubes shall be half hard copper tube of accepted standard approved by the
Engineer.
10.6.2
Copper Fittings, Waste Pipes, Ball Valves etc.
All fittings shall be of an accepted standard approved by the Engineer and as
described on the drawings.
10.6.3
uPVC Pressure Pipes and Fittings
uPVC pressure pipes and fittings for water supply shall be of an accepted
standard approved by the Engineer.
10.6.4
Workmanship
The plumbing installation shall be carried out to the satisfaction and in
accordance with the Acts and By-laws of the Dubai Electricity and Water
Authority.
10.6.5
Pipework
All pipework shall be neatly executed in long lengths to avoid unnecessary
jointing. Horizontal pipes shall be fixed with a slight fall to prevent airlocks and
to enable the system to be easily drained down.
10.6.6
Copper Tube Fixing
Copper tube shall be fixed clear of walls and ceilings with two piece copper
spacing clips or with proprietary plastic pipe clips. Clips shall be at 1.20m
horizontally and 1.50m vertically for 15mm diameter pipes and at 1.80m and
2.40m respectively for 22mm and 28mm diameter pipes. Capillary joints shall be
neatly made with all surplus solder removed.
Screw threads on compression joints shall be wrapped with PTFE tape prior to
tightening.
10.6.7
Waste Pipes
uPVC waste pipes for sinks and urinals shall be fixed and jointed in accordance
with the manufacturer's instructions. Fixing clips shall be at 0.50m horizontally
and 1.20 m vertically and joints shall be by 'O' rings, seals or solvent cement.
Care shall be taken to allow for expansion in accordance with manufacturer's
instructions.
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SECTION 10
BUILDING SPECIFICATIONS
10.6.8
Sleeves
uPVC sleeves shall be provided through walls and ceilings for pipes and shall be
internally 3 mm minimum larger than the pipes.
10.6.9
Testing
Soil and waste pipes shall be air tested for leaks to a pressure of 38 mm water
gauge, constant for three minutes.
Rainwater pipes shall be tested for leaks as above and gutters shall be tested by
filling with water to overflow level.
Testing shall be undertaken to hidden sections of pipework before they are
built-in.
All leaks found shall be rectified and retested.
10.6.10
Storage Tanks
GRP cold water storage tanks shall be placed on 2 nos. galvanised mild steel
brackets bolted to the wall.
10.7
PLASTERWORK & OTHER WALL, FLOOR & CEILING FINISHES
10.7.1
Cement
10.7.2
Cement shall be Portland Cement as described in Section 3.
Lime
Lime shall be the hydrated type to the approved standard.
10.7.3
Sand
Sand for plasterwork with gypsum plasters shall be suitable for use with the brand
of gypsum plaster used. Sand for rendering, internally and externally, and floor
screeds shall comply with Clause 5.1.3.
10.7.4
Gypsum Plasters
Gypsum plaster shall be of an accepted standard approved by the Engineer.
10/9
SECTION 10
BUILDING SPECIFICATIONS
10.7.5
Plaster Trims
Metal angle beads and plaster stops for plasterwork and plasterboard shall be
manufactured from galvanised mild steel.
10.7.6
Metal Lathing
Metal lathing shall be manufactured from galvanised mild steel having a
minimum shortway aperture of 6 mm.
10.7.7
Plasticizers
Plasticizers shall be an approved vinyl resin type and used in the manner and
proportions recommended by the manufacturer.
10.7.8
Bonding Agents
Bonding agents generally shall be an approved polyvinyl acetate (PVA) type and
used in the manner and proportions recommended by the manufacturer.
10.7.9
Storage
Plaster shall be stored in a building in dry condition on timber platforms and shall
be used within two months of manufacture.
Plasterboards shall be stored in a building in dry condition and shall be laid flat
and stacked on a sheet of polythene.
10.7.10
Floor Tiles
Vitrified and fully vitrified floor tiles shall be as detailed on the drawings.
Floor tiling shall be laid with a proprietary tile adhesive (approved by the
Engineer) either directly onto a clean, dry and level concrete sub-floor, or on a
cement/sand screed laid over the sub-floor. The sub-floor surface shall be
scabbled to remove all surface laitance prior to tiling or screeding. The screed
shall be mixed semi-dry by hand or in a pan mixer and shall be a 1:4
cement/sharp sand mix with just enough water to enable it to hold together when
squeezed in the hand. The sub-floor shall be kept damp for 24 hours and the
screed shall be laid and well compacted to a thickness of 56mm and brought to
the required levels using a draw float. The finished floor screed shall be kept
damp for a period of 7 days prior to commencement of tiling. The tile adhesive
shall be spread evenly by steel trowel to a thickness of 3mm onto which the clean,
10/10
SECTION 10
BUILDING SPECIFICATIONS
dry tiles shall be laid to give a 3mm minimum joint width. The tiles shall be
grouted with a proprietary and approved tile grout within a minimum period of 24
hours after laying.
10.7.11
Wall Tiles (Internal)
Coloured wall tiles shall be 152 x 152 x 5.5mm thick glazed tiles approved by the
Engineer.
10.7.12
Wall Tiles (External)
External wall tiles shall be as detailed on the drawings.
The concrete surface to receive tiling shall be prepared as follows :1)
Concrete surface to be 100% keyed by either bush hammering, hacking or
water scabbling of smooth surface.
2)
Concrete surface shall be thoroughly moistened and a concrete slurry mix
of one part cement to two parts of medium sharp sand applied as
splatterdash thrown onto concrete surface.
3)
While the surface is wet apply 1:3.5 mix sand/cement render to a thickness
of 12mm in two coats to a plumb and level finish and with wood float
finish.
The completed rendering is to be protected and allowed to dry slowly with
damping as necessary. After curing, the surface is to be allowed to dry completely
before the fixing of tiles.
Tiles shall be fixed with proprietary tile adhesive (approved by the Engineer). The
tiles are to be bedded strictly in accordance with the manufacturer's instructions
with 10mm joints between tiles.
At least 24 hours after fixing tiles are to be jointed using approved mortar.
Movement joints are to be formed between tiles in positions shown on the
drawings to the full depth of the tiles, bedding and render. Joints are to be 10mm
wide and are to be filled to within 8mm of surface with inert filler and finished
with 2 part polysulphide pointing in colour to match tile jointing.
10.7.13
Tile Adhesive
10/11
SECTION 10
BUILDING SPECIFICATIONS
Tile adhesive for floor and wall tiling shall be as recommended by the Tile
Manufacturer and used in accordance with the adhesive manufacturer's
instructions.
10.7.14
Tile Grout
Tile grout for floor or wall tiles shall be as recommended by the manufacturers of
the ceramic tiles and used in accordance with the manufacturer's instructions.
10.7.15
Expansion Joints
Expansion joints in floor and wall tiling shall be 6.5 mm wide Polyethylene
backing strip with 6.5 mm wide approved silicone sealant, gun applied on the face
in accordance with the manufacturer's instructions.
Expansion joints in floor tiling shall be at 6 m maximum centres in both
directions and around the perimeter of rooms, over structural joints and around
machine bases and holes in the floor. The joints shall be the full depth of the floor
tiles, bedding and screed x 6.5 mm minimum width. The joints shall be primed
with two coats of approved primer and when dry, filled up to within 6 mm of the
tile finish with polyethylene compressible foam strip. An approved joint sealant
shall then be gun applied and tooled to a slightly concave smooth even finish.
10.7.16
Backgrounds
All backgrounds shall be clean, dry, free from efflorescence, paint, oil and dust
and adequately prepared to provide a good key. All loose, flaking and unsound
material shall be completely removed and all mortar joints shall be raked out, if
required, to a minimum depth of 10 mm. Concrete surfaces shall be well wetted
five minutes prior to plastering or rendering.
10.7.17
Dissimilar Materials
Joints between dissimilar materials such as blockwork and concrete shall be
covered with a 300 mm wide continuous strip of expanded metal lathing fixed to
both sides with masonry nails or plugs and screws at 200 mm centres.
10.7.18
Hacking
Concrete surfaces shall be well hacked to expose the aggregate thus providing a
firm coarse textured background.
10/12
SECTION 10
BUILDING SPECIFICATIONS
10.7.19
Dubbing Out
Dubbing out of all areas to receive plaster or render shall be in the same mix as
the subsequent coat, not exceeding 10 mm thickness in one application, and shall
be allowed to harden.
10.7.20
Splatterdash or Stipple Coat
Splatterdash or stipple coats shall consist of 1:1.5 cement/sharp sand mixed with
50% water/50% PVA bonding agent to form a thick slurry. The mixture shall be
vigorously brushed onto the background and stippled to give a close textured key.
The resulting finish shall be kept damp to prevent rapid drying out and allowed to
harden for seven days minimum before subsequent coats are applied.
10.7.21
Internal Finishes-General
All internal finishes shall not commence until the building is watertight, including
glazing, and reasonably dried out.
10.7.22
Internal Render
Internal render shall be applied to concrete blocks as follows :The render shall be two coat work comprising a stipple coat as described
previously and a finishing coat giving a maximum thickness of 12 mm. The mix
shall be in the proportion 1:1:6 cement/lime/sand. The render shall be kept damp
for a minimum of three days. All window and door openings must be closed to
prevent through draughts causing rapid drying out.
10.7.23
Stucco
A PVA copolymer based putty for concrete and plaster shall be applied, in
accordance with the manufacturer's instructions, to the surface of the internal
render after curing has taken place. The stucco shall only be applied in sufficient
thickness to seal the surface of the render and remove minor surface irregularities
to give a smooth surface ready to receive the decorative finish.
10.7.24
External Render
External render shall be applied to concrete, concrete blocks and clay bricks as
follows :-
10/13
SECTION 10
BUILDING SPECIFICATIONS
The render shall be three coat work comprising a stipple coat as described
previously, an undercoat and a finish coat giving a maximum thickness of 16 mm.
The mixes shall be in the proportions shown on the schedule of mixes. The
undercoat shall be level, true and of sufficient thickness to prevent the
background joints showing through and shall be kept damp for three days before
applying the final coat.
Where shown on the drawings the final coat shall be approximately 5 mm thick
coloured Tyrolean open honeycombed texture machine applied render.
A key for the final coat shall be provided by combing the undercoat prior to
setting with wavy lines 20 mm apart and 5 mm deep. The final coat shall be 6 mm
minimum thickness and worked to a level and smooth finish with a wooden float
with clean, true and level arises. The whole shall be protected from rapid drying
out in hot, dry and windy weather.
Table 10-1. Schedule of Mixes for External Render
Concrete,Concrete Blocks Aerated Concrete Blocks
Mix Type
or Engineering Bricks
of Soft Clay Bricks
Undercoat
Finish
Undercoat Finish
Cement:Lime:Sand
Cement:Ready-Mixed
Lime / Sand
Cement:Sand with
Plasticizers
10.8
GLAZING
10.8.1
Glass
1:1.5:4
to 4.5
1:4
to 4.5
1:3
to 4
1:1:5
to 6
1:5
to 6
1:5
to 6
1:2:8
to 9
1:8
to 9
1:7
to 8
1:2:8
to 9
1:8
to 9
1:7
to 8
Glass for glazing shall be the best of its respective kind and free from blemishes
and imperfections. Glass shall be as shown on the drawings.
10.8.2
Bedding Compound
The bedding compound for external glazing shall be an approved non-setting
butyl rubber based proprietary compound and sufficiently elastic to allow for
thermal or other movement of the glass and timber, compatible with the approved
decorative wood stain.
The bedding compound shall show no sign of separation after bedding.
10/14
SECTION 10
BUILDING SPECIFICATIONS
10.9
PAINTING AND DECORATING
10.9.1
Painting-General
All primers, oil bound undercoats and finishes, emulsions and polyurethane
interior varnishes shall be used in strict accordance with the manufacturer's
recommendations and shall be obtained from an approved manufacturer.
Only fresh paint delivered to site in original sealed containers shall be used. Each
container shall be labelled with the manufacturer's name, contents, colour,
quantity, batch number and date and instruction on method of application.
10.9.2
Exterior Stain
Pigmented stain shall be PX 65 as manufactured by Sadolin's Ltd., and used in
accordance with their recommendations, or other equal and approved, two coats
before fixing and one coat after fixing.
10.9.3
Workmanship
All painting shall be carefully executed with clean brushes and in the best manner
and applied strictly in accordance with the manufacturer's instructions.
All paints, stains and varnishes shall be well stirred before use and thinned only in
accordance with the manufacturer's recommendations.
Painting of exterior work shall not be carried out in wet, dusty or foggy weather
and interior work shall not proceed in dusty conditions.
All woodwork shall be prepared to a fine clean finish by scraping or sanding all
made dust free immediately before painting and coating.
10.9.4
Stopping to Plaster
Plaster shall be clean and dry and free from loose material. Holes and cracks shall
be cut back and solidly filled, allowed to dry and rubbed down smooth.
10.9.5
Steel Priming
10/15
SECTION 10
BUILDING SPECIFICATIONS
Mild steel shall be blast cleaned and primed with two coats of primer within four
hours of cleaning.
Galvanised mild steel shall be degreased with white spirit and primed with two
coats of primer.
10.9.6
Oil-Based Paint
Interior primed softwood and all primed mild steel shall be painted with two
undercoats and one gloss or semi-matt finish coat of oil-based paint to give a
smooth, even and solid finish, all as instructed. Each coat shall dry overnight
before applying further coats.
10.9.7
Internal Finish to Walls
The paint finish to internal walls shall be PVA copolymer matt emulsion paint or
as detailed on the drawings.
10.9.8
Ironmongery
All fixed ironmongery except hinges shall be removed before painting and refixed
on completion.
10/16