Appendix 6:NSAI Quality Assurance Schemes
A6.1
NSAI Timber Frame Quality Approval Scheme
The National Standards Authority of Ireland (NSAI) Timber Frame Manufacturers’ Quality
Approval Scheme is for firms that:
Design and/or manufacture timber frame buildings for the Irish market.
Have in operation, or agree to implement within an agreed time period, a Quality System for
the design and manufacture of timber frame building components, approved by the NSAI.
Have a NSAI approved Quality Control Supervisor responsible for the operation of the Quality
System and for liaison with NSAI.
Scope
The scheme is applies either to companies that manufacture domestic dwellings not exceeding 4
storeys in height or is applicable to non-domestic buildings. The quality approval scheme is not
applicable to on-site fabrication of panels (‘stick building’). The scheme is based on the
requirements of the Irish Building Regulations, the Technical Guidance Documents to the Irish
Building Regulations and relevant Irish and British standards.
Assessment for Membership
The applicant company is assessed by NSAI. The assessment includes an inspection visit to the
plant and an evaluation of the applicant’s quality system including:
Design
Quality procedures related to design and manufacture
Material specifications
Manufacturing process
Manufacturing information and documentation
Production facilities
Site information and documentation
Quality records
Personnel
Training
Quality Surveillance and Inspection
Appendices
A6.1
The NSAI will, at its discretion, send an officer to the company’s works to examine the timber frame
building/s and/or components for compliance with the requirements of the approval scheme.
Member companies must grant NSAI full access to their manufacturing plant, offices and records.
The NSAI will:
Check that the requirements of the Quality Approval Scheme are being complied with.
Inspect the manufacturing premises as it sees fit. The number of inspections will vary but
usually at least two inspections will be carried out annually. Visits may be unannounced.
Check the quality records for the design and manufacture of timber frame buildings and/or
components.
Check structural design calculations on a random basis as it sees fit.
Responsibilities of NSAI
NSAI shall maintain a National Register of approved Timber Frame Manufacturers. This list shall
be widely circulated. NSAI shall promote the Quality Approval Scheme for the benefit of the timber
frame industry.
Responsibilities of Member Companies
Membership
The company shall implement and operate a Quality System approved by NSAI for the design
and manufacture of timber frame buildings. The member company shall notify NSAI of any
changes in the quality system, materials, design, manufacture, personnel or any other matter, that
may affect compliance with the approval scheme. While the membership of the scheme is in force,
the member company shall abide by the rules and regulations set out in this document and the
articles of association of the NSAI.
Failure to comply with requirements of the scheme may lead to the suspension of the member
company from the scheme. Suspension from the scheme will result in the deletion of the member
company’s entry in the National Register of approved companies and the member company will be
required to discontinue the use of the approval mark.
Supervision and Inspection
The manufacturer shall exercise the necessary control at all stages of design and manufacture as
required by the NSAI. The quality system shall ensure that all timber frame components are in
compliance with the specification and design requirements.
Appendices
A6.2
Quality Records
Adequate records shall be kept on customers, design, materials, production, delivery, training and
site locations. Records shall be made available to NSAI on request. Records shall be kept for a
minimum period of 10 years.
Materials Specification
The manufacturer shall have their materials specification approved by NSAI. Any proposed
changes in the materials specification shall be approved in writing by the NSAI in advance.
NSAI Approval Marking
Every timber frame panel shall display a NSAI Approval Tag showing the following information:
NSAI logo; the words ‘Approved Timber Frame Manufacturer’; company name; company
registration number. Tags shall be positioned in accordance with clause 8.8.
Documentation for Site
The manufacturer shall ensure that standard documentation relevant to site work and to the
erection of timber frame buildings are delivered to every site. The manufacturer shall ensure that
any special instructions and/or construction details issued by the designer are delivered to each
site for every building type.
Use of NSAI Mark in Advertising and Marketing
NSAI will permit any member company to declare its membership of this Quality Approval
Scheme in any marketing activity providing membership is current. However, prior written
permission shall be obtained from the NSAI for any marketing or advertising items using the NSAI
name and/or logo.
Design
Designer
Timber frame buildings produced under this scheme shall be designed by a suitably qualified and
experienced structural engineer. This engineer should be covered by appropriate indemnity
insurance. Building designs shall cover the whole building. Building designers shall take account of
the location and exposure of the site in accordance with the appropriate loading code. Normally the
manufacturer or his nominated designer is responsible only for the design of the timber frame
structure and other components supplied by the manufacturer to site.
Appendices
A6.3
This Quality Approval Scheme assesses the design system used by the member company and
does not approve individual building designs. Responsibility for design rests solely with the design
engineer.
Design Codes and Standards
Timber frame buildings designed and manufactured under this scheme shall:
Comply with the Irish Building Regulations
Comply with the relevant provisions of the following standards:
BS 5268: ‘The Structural Use of Timber’
Part 2: ‘Code of practice for permissible stress design, materials and workmanship’
Part 4: ‘Fire resistance of timber structures’
Part 5: ‘Code of practice for the preservative treatment of structural timber’
Part 6: ‘Code of practice for timber frame walls’
IS 193: ‘Timber trussed rafters for roofs’
BS 6399: ‘Design loading for buildings’
Part 1: “Code of practice for dead and imposed loads”
Part 3: “Code of practice for imposed roof loads”
Part 2: “Code of practice for wind loads” or
CP3:
Chapter V: ‘Code of basic data for the design of buildings’
Loading: Part 2 Wind loads
Attention is also drawn to the following:
The Timber Frame section of the HomeBond House Building Manual gives typical details
and recommendations for site work. It generally represents good building practice.
NSAI information sheet ‘Reference documentation for timber frame construction’.
Structural calculations
The designer shall issue to the timber frame manufacturer a copy of the structural calculations for
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A6.4
each site location and each building type. The timber frame manufacturer shall keep on record a
copy of all structural calculations and a copy of any special instructions and/or construction details
issued by the designer.
Structural certificates
The designer shall issue to the manufacturer a Structural Certificate covering the design of each
building type. This certificate shall reference the site and state that the design complies with the
Irish Building Regulations and the rules of this scheme. The manufacturer shall hold a copy of this
certificate where it shall be available for inspection on request.
Design documentation for manufacture
The timber frame building designer is required to issue to the manufacturer clear information and
instructions for the manufacture and erection of timber frame components and buildings.
NSAI inspections
The manufacturer shall make calculations, drawings, specifications, etc. available for NSAI
inspection on request.
Manufacturing Requirements
Quality System
All timber frame components including wall, floor and roof panels shall be factory fabricated under
a NSAI approved Quality System.
Structural timber
All structural timber shall be visually strength graded to IS 127 or BS 4978 or machine graded to
IS/BS EN519 and marked accordingly.
Roof trusses
Prefabricated roof trusses shall be manufactured to IS 193 under a Quality System approved by
NSAI and tagged accordingly.
Materials
All materials shall comply with the materials specification (see section 6.4).
Timber moisture content
The manufacturer shall ensure that all timber materials at time of manufacture and delivery are at
Appendices
A6.5
the correct moisture content as laid out in the materials specification.
Preservative treated timber
All timber in external walls and external wall panels shall be treated with wood preservative in
accordance with BS 5268: Part 5. The manufacturer shall hold a copy of all treatment certificates
and shall make them available for inspection on request.
Sheathing grade mark
The sheathing used in wall panels shall be placed so that the grade mark of the sheathing
manufacturer will be visible on the inside face of the wall panel.
NSAI Approval Mark - positioning
The NSAI tag shall be fixed to individual panels so as to be clearly visible in the following
locations:
External wall panels: at a top corner on the external face (over the breather membrane)
Internal wall panels (only if fire resisting and/or load-bearing): at a top corner
Floor panels: to the face of a floor joist or the underside of the sheathing in a central location.
Roof panels: to the face of a roof rafter or the underside of the sheathing in a central location.
A6.2
NSAI Timber Frame Site Inspection Scheme
Introduction
The proposed NSAI Timber Frame Site Inspection Scheme will be applicable to timber frame
residential buildings being built in Ireland. The scheme is based on the requirements of the Irish
Building Regulations, generally good building practice and where appropriate the HomeBond
House Building Manual.
Scope
The Inspection Scheme administered on a pilot basis for uptake by loacal authorities for a fee and
is open to timber frame residential buildings not exceeding 4 storeys in height. The scheme is
generally applicable to building sites containing 5 or more buildings. The Inspection Scheme is not
applicable to site fabricated buildings (‘stick buildings’). The scheme is subject to a prior agreement
on the work schedule and terms with NSAI. NSAI at all times reserve the right to apply the scheme
to any particular site.
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A6.6
Inspection Service
Compliance with design requirements
Compliance with the materials specification
Compliance with the building specification
Compliance with the timber frame manufacturer’s construction details
Compliance generally with good site practice and the Irish Building Regulations
Compliance with any specific or special requirements of the project manager/architect/local
authority.
In addition the NSAI’s routine procedures will include;
Inspection of roof members
Checks for timber preservation treatment and confirmation of treatment
Moisture content of timber components
Site storage of timber components
Confirmation of timber grade/strength class
General quality of panel manufacture
Site fixings
Joinery
Painting (if required)
The NSAI inspectors will undertake regular site inspections and submit regular reports to the
project manager/architect/local authority or agreed recipient. Where appropriate NSAI reports will
include recommendations to the project manager/architect/ local authority or agreed report
recipient.
The NSAI will endeavour to ensure confidentiality in all matters relating to inspections and the
operation of the scheme.
The NSAI and/or its agents cannot take any responsibility for the design or the erection of buildings
in relation to compliance with the Building Regulations or any other requirements. Note that the
NSAI provide training courses related to good site practices for timber frame construction and in
addition can advise on building and materials specifications.
Appendices
A6.7