Publishing and copyright information

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

The following BSI references relate to the work on this document:
Committee reference B/546
Draft for comment 18/30371976 DC

Foreword

Publishing information

This British Standard is published by BSI Standards Limited, under licence from The British Standards Institution, and came into effect on 30 November 2018. It was prepared by Technical Committee B/546, Flexible Sheets For Waterproofing. A list of organizations represented on this committee can be obtained on request to its secretary.

Supersession

This British Standard supersedes BS 6229:2003, which is withdrawn.

Information about this document

This code of practice deals with the overall principles of design, construction, care and maintenance of flat roofs with a continuously supported flexible waterproof covering. It does not deal with metal roof coverings which are now the responsibility of B/542, Roofing and cladding products for discontinuous laying.

Since publication of the previous edition of this code of practice (BS 6229:2003), many changes have taken place in the functional requirements for buildings, in the performance capability of roofing materials and in some aspects of building practice. The original code of practice has, therefore, undergone a comprehensive review and updating.

NOTE Guidance on the methodology of condensation risk analysis is now covered by BS 5250, workmanship is now covered by BS 8000‑4 and guidance on sound insulation and noise reduction for buildings is now covered in BS 8233.

Use of this document

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.

In drafting this code of practice it has been assumed the design and construction of the roof is entrusted to appropriately qualified and competent people and the building owner follows the recommendations concerning inspection, care and maintenance of the roof during its service life.

Any user claiming compliance with this British Standard is expected to be able to justify any course of action that deviates from its recommendations.

Presentational conventions

The provisions of this standard are presented in roman (i.e. upright) type. Its recommendations are expressed in sentences in which the principal auxiliary verb is “should”.

Commentary, explanation and general informative material is presented in smaller italic type, and does not constitute a normative element.

Where words have alternative spellings, the preferred spelling of the Shorter Oxford English Dictionary is used (e.g. “organization” rather than “organisation”).

The word “should” is used to express recommendations of this standard. The word “may” is used in the text to express permissibility, e.g. as an alternative to the primary recommendation of the clause. The word “can” is used to express possibility, e.g. a consequence of an action or an event.

Notes and commentaries are provided throughout the text of this standard. Notes give references and additional information that are important but do not form part of the recommendations. Commentaries give background information.

Contractual and legal considerations

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 cannot confer immunity from legal obligations.

1 Scope

This revised edition of BS 6229 describes best current practice in the design, construction, care and maintenance of roofs with a flat or curved surface, at a pitch not greater than 10 degrees to the horizontal, with a continuously supported flexible waterproof covering. The supporting structure is either dense and heavy (such as a concrete slab), or consists of framing members supporting a lightweight deck of metal or of timber-based material.

NOTE Provided that the design conditions are similar, many of the recommendations contained in this code of practice apply to roofs at pitches greater than 10 degrees and to those designed as a Green Roof supporting planting.

This British Standard does not apply to certain types of cold stores and high temperature enclosures.

2 Normative references

3 Terms and definitions

3.6 layers

3.7 roofs

4 Design

4.1 General design considerations

4.2 Types of flat roof system

4.3 Structure

4.4 Roof falls to achieve drainage

4.5 Rainwater disposal

4.6 Thermal performance

4.7 Control of condensation

4.8 Sound attenuation

4.9 Fire safety

4.10 Surface protection

4.11 Rooftop components and installations

5 Materials

5.1 General

5.2 Roof slab/deck materials

5.3 Screeds

5.4 Waterproof layers

5.5 Thermal insulation

5.6 Air and vapour control layers

5.7 Vapour permeable membranes (breather membranes)

6 Workmanship

7 Care and maintenance

7.1 Owner's Building Information Manual

7.2 Inspections

7.3 Maintenance procedures

7.4 Repair/renewal

Bibliography

BS 6229:2018

Flat roofs with continuously supported flexible waterproof coverings. Code of practice

Current, Under Review

Published:

30 Nov 2018