BS 5642-1 is the first part of the multiple series that specifies requirements for window sills of precast concrete, cast stone, clayware, slate and other natural stone for use with windows complying with the requirements of BS 644, BS 6510 and BS 4873.
Note 1: BS 5642-1 does not cover masonry units conforming to the requirements of BS EN 771 (all parts).
Note 2: Cast stone units not containing reinforcement or fixings and not exceeding 650 mm in any co-ordinating dimension are covered by BS EN 771-5.
BS 5642-1 on window sills of precast concrete, cast stone, clayware, slate and natural stone is useful for:
BS 5642-1 defines the dimensions, performance characteristics, construction details, and specifications of window sills for use with windows that conform with the standard. The sulfuric acid immersion test for slate and the wetting and drying test for slate are both covered by BS 5642-1, which also allows you to check the specimens using a two-diameter lens.
Overall, you can apply BS 5642-1 while assembling windows to improve their quality and longevity.
BS 5642-1:1978+A1:2014 supersedes BS 5642-1:1978, which is withdrawn
The principal changes in BS 5642-1:1978+A1:2014 are: