Committees responsible for this British Standard

The preparation of this British Standard was entrusted by Technical Committee B/209, General building codes, to Subcommittee B/209/1, Flat roofs, upon which the following bodies were represented:

Association of Building Component Manufacturers (ABCM)

Association of British Roofing Felt Manufacturers (ABRFM)

Aluminium Federation

BRE Certification

BRE/LPC Laboratories

Building Research Establishment (BRE)

British Rigid Urethane Foam Manufacturers Association (BRUFMA)

Copper Development Association (CDA)

Cork Industry Federation

Eurisol (UK Mineral Wood Association)

European Liquid Roofing Association (ELRA)

Flat Roofing Alliance — Contractors (FRA)

Flat Roofing Alliance — Manufacturers (FRA)

Institute of Structural Engineers

Lead Sheet Association (LSA)

Local Authority Organizations

Mastic Asphalt Council Ltd. (MAC)

National Federation of Roofing Contractors (NFRC)

Royal Institute of British Architects (RIBA)

Scottish Office (Construction and Building)

Single Ply Roofing Association (SPRA)

Thermal Insulation Manufacturers and Suppliers Association (TIMSA)

Wood Panel Industries Federation (WPIF)

First edition December 1982 Second edition March 2003

The following BSI references relate to the work on this British Standard:

Committee reference B/209/1 Draft for comment 00/105250 DC

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 26 March 2003

Foreword

This British Standard code of practice has been prepared by Technical Committee B/209/1. It supersedes BS 6229:1982, which is withdrawn.

This code of practice deals with the overall principles of design and application of flat roofs with continuously supported roof coverings. A flat roof is defined as having a pitch not greater than 10° to the horizontal.

Where the particular use of individual materials or forms of construction is covered by other, specific codes of practice, detailed reference should additionally be made to the normative references in Clause 2.

Since publication of the first edition of this code of practice (1982), many changes have taken place in the functional requirements for buildings, in the performance capability of many roofing materials and in some aspects of building practice. The original code of practice has, therefore, undergone a comprehensive review and updating.

Extensive guidance on the analysis of condensation risks in flat roof construction was given in the first edition of this code of practice. Guidance on the methodology of condensation risk analysis is now covered by BS 5250. Specific guidance on criteria and assumptions that are relevant to flat roof construction are retained in this revision of this code of practice.

The 1982 edition of this British Standard dealt with both design and workmanship. Workmanship is now covered by BS 8000‑2.2, -3, -4, -5, and -9.

As a code of practice, this British Standard takes the form of guidance and recommendations. It should not be quoted as if it were a specification and particular care should be taken to ensure that claims of compliance are not misleading.

NOTE It has been assumed in the drafting of this code of practice that the design and construction of flat roofs is entrusted to appropriately qualified and competent people. It has also been assumed that the building owner will adopt the recommendations in respect of planned inspection and maintenance of a roof during service.

This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.

Compliance with a British Standard does not of itself confer immunity from legal obligations.

Attention is drawn to the following statutory regulations relating to construction safety (see also Clause 20): The Construction (General Provisions)

Regulations 1961 [1], The Construction (Lifting Operations)

Regulations 1998 [2], The Construction (Notice of Accident, etc.) Orders 1964 [3],

The Construction (Working Places) Regulations 1966 [4], The Construction (Health, Safety and Welfare) Regulations 1996 [5], Health and Safety at Work etc. Act 1974 [6].

Summary of pages

This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 37 and a back cover.

The BSI copyright notice displayed in this document indicates when the document was last issued.

1 Scope

This code of practice gives recommendations on the design and application of flat roofs with continuously supported roof coverings. It covers weathertightness, drainage, thermal design, sound insulation, condensation control, structural support, fire precautions, maintenance and repair. The recommendations are applicable to terraces, podia, parking decks and green/garden roofs; however these particular types of roof also require consideration of additional factors, beyond the scope of this code of practice.

This code of practice is applicable to roof coverings at a pitch not greater than 10° to the horizontal.

NOTE Provided that the design conditions are similar, the recommendations given in this code may also be applied to roofs with slopes greater than 10°, but for steep roofs many of the recommendations may not apply.

This code of practice does not apply to roofs with self-supporting coverings, cold stores and high temperature enclosures, or to slated or tiled roofs.

2 Normative references

3 Terms and definitions

4 Types of flat roof

4.1 General

4.2 Principal types

4.3 Other types

5 Materials and components

5.1 General

5.2 Roof coverings

5.3 Structural deck

5.4 Screeds

5.5 Thermal insulation materials

5.6 Vapour control layers (VCLs)

5.7 Roof surface protection

5.8 Rooflights

5.9 Rainwater goods

5.10 Lightning conductors

5.11 Handrails and balustrades

6 General design considerations

7 Falls and drainage

7.1 General

7.2 Minimum finished falls

7.3 Design falls

7.4 Direction of falls

7.5 Formation of falls

8 Structural design

8.1 Loading

8.2 Strength and stiffness

8.3 Movement

8.4 Protection against trapped moisture

9 Thermal design

9.1 General

9.2 Thermal conductivity

9.3 Thermal bridges

9.4 Thermal mass

9.5 Choice of insulating materials

9.6 Positioning of thermal insulation

10 Control of condensation

10.1 General considerations

10.2 Design considerations

10.3 Types of roofs in relation to interstitial condensation

10.4 Condensation at thermal bridges

11 Sound insulation

11.1 General

11.2 Sound insulation across the roof

11.3 Sound insulation along the roof

11.4 Sound absorption

12 Fire precautions

12.1 General

12.2 Insurance

12.3 Internal fire

13 Surface protection

13.1 Solar protection

13.2 Damage from traffic

13.3 Inverted roofs

14 Rooflighting

14.1 General

14.2 Daylighting recommendations

14.3 Weathertightness

14.4 Thermal insulation

14.5 Condensation

14.6 Fire precautions

14.7 Sound insulation

14.8 Safety considerations

15 Roof plant, equipment and fixtures

16 Security

17 Durability of roof coverings

18 Maintenance and repair

18.1 Maintenance

18.2 Repair

19 Refurbishment and renewal

20 Safety

Bibliography

BS 6229:2003

Flat roofs with continuously supported coverings. Code of practice

Published:

26 Mar 2003

Withdrawn:

23 Nov 2018