Co-operating organizations

The committee responsible for the preparation of this British Standard consists of representatives of the following Government departments and scientific and industrial organizations:

Association of British Roofing Felt Manufacturers Ltd.

British Lead Manufacturers’ Association

British Non-Ferrous Metals Federation

British Paper and Board Makers Association

British Plastics Federation

Confederation of British Industry

Copper Development Association

English Slate Quarries Association

Greater London Council

Institute of Petroleum

Institution of Municipal Engineers

Lead Development Association

Mastic Asphalt Council and Employers’ Federation

Ministry of Public Building and Works

Ministry of Public Building and Works Building Research Station

National Federation of Building Trades Employers

National Federation of Clay Industries

North Wales Slate Quarries Association

Royal Institute of British Architects

Royal Institution of Chartered Surveyors

This British Standard, having been approved by the Building Divisional Council, was published under the authority of the Executive Board on 30 October 1970

The following BSI references relate to the work on this standard:

Committee reference B/34 70/6015

Foreword

This standard makes reference to the following British Standards and Special Publication:

BS 12, Portland cement (ordinary and rapid-hardening).

BS 146, Portland-blastfurnace cement.

BS 410, Test sieves.

BS 598, Sampling and examination of bituminous mixtures for roads and buildings.

BS 890, Building limes.

BS 1097, Mastic asphalt for tanking and damp-proof courses (limestone aggregate). [Included in BS 988, BS 1097, BS 1076, BS 1451. Mastic asphalt for building (limestone aggregate).]

BS 1178, Milled lead sheet and strip for building purposes.

BS 1200, Sands for mortar for plain and reinforced brick-work; blockwalling and masonry. (Included in BS 1198‑1200. Building sands from natural sources).

BS 1418, Mastic asphalt for tanking and damp-proof courses (natural rock asphalt aggregate). [Included in BS 1162, BS 1410, BS 1418. Mastic asphalt for building (natural rock asphalt aggregate).]

BS 2870, Rolled copper and copper alloys, sheet strip and foil.

BS 3235, Test methods for bitumen.

BS 3921, Clay bricks and blocks.

BS 4027, Sulphate-resisting Portland cement.

BS 5642, Sills and copings — Part 1: Specification for window sills of precast concrete, cast stone, clayware, slate and natural stone.

BS 6398, Specification for bitumen damp-proof courses for masonry.

BS 6515, Specification for polyethylene damp-proof courses for masonry.

BS 8215, Code of practice for design and installation of damp-proof courses in masonry construction.

CP 3, Code of basic data for the design of buildings — Chapter IX: Durability.

DD 86, Damp-proof courses.

This metric revision of BS 743 has been prepared under the authority of the Building Divisional Council, as part of the change to the metric system in the construction industry, giving values in terms of SI units. For further information on SI units, reference should be made to PD 5686¹⁾.

This standard will eventually be superseded by new or existing standards covering the following classes of material for damp-proof courses:

Lead and copper, sheet thicknesses.
Bitumen damp-proof sheeting with varying base materials, indicating the filler content and the maximum softening point of the coating bitumen on the addition of filler.
Mastic asphalts, suitable for damp-proof courses.
Low density black polythene sheeting.
Materials used in mortars for bedding damp-proof courses, ordinary, rapid hardening, blastfurnace and sulphate resistant cements. Building limes and sands.
Slates, with the requirements for “wetting and drying” and sulphuric acid immersion tests.
Bricks and blocks manufactured from fired brickearth, clay or shale.

Research is in progress to develop test methods as a basis for future performance based specifications for damp-proof courses (see DD 86).

Guidance on the design and installation of damp-proof courses is given in BS 8215. The importance of correct laying is emphasized since the efficiency of the damp-proof course depends as much on the method of use and workmanship employed as upon the intrinsic quality of the materials. In particular, the composition of the mortar and the workmanship used for bedding bricks and slates is of great importance when laying damp-proof courses near ground level.

Materials used as damp-proof courses in walls constructed with modular components designed in accordance with BS 4330²⁾ and PD 6444³⁾ should have widths in accordance with BS 4011⁴⁾.

A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application.

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

Summary of pages

This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 4, an inside back cover and a back cover.

This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.

1 Scope

This British Standard specifies requirements for the following materials suitable for use in the construction of damp-proof courses:

2 Lead

3 Copper

4 Bitumen

5 Mastic asphalt

6 Polyethylene

7 Slates

8 Bricks

9 Mortar

10 Designation for ordering

BS 743:1970

Specification for materials for damp-proof courses

Current

Published:

30 Oct 1970