Approved Document C - Site preparation and resistance to contaminants and moisture

Approved Document C
(Download from Planning Portal)

MAIN CHANGES IN THE 2004 EDITION

This edition of Approved Document C, Site preparation and resistance to contaminants and moisture, replaces the 1992 (with 2000 amendments) edition. The main changes are:

a) Site investigation is now recommended as the method for determining how much unsuitable material should be removed.

b) Requirement C1(2) now applies to material change of use as set out in Regulations 5 and 6.

c) Remedial measures for dealing with land affected by contaminants have been expanded to include biological, chemical and physical treatment processes.

d) The area of land that is subject to measures to deal with contaminants now includes the land around the building.

e) Guidance on protection from radon is expanded to include buildings other than dwellings.

f) Guidance is included relating to sub-soil drainage and the risk of transportation of water-borne contaminants.

g) New guidance recommends that in order to reduce the condensation risk to floors, walls and roofs reference should be made to the revised BS 5250 and "Limiting thermal bridging and air leakage: robust details" and BR 262 "Thermal insulation: avoiding risks."

h) Guidance is now provided on the use of moisture resistant boards for the flooring in bathrooms, kitchens and other places where water may be spilled from sanitary fittings or fixed appliances.

i) Reference is made to BS 8208 for assessing the suitability of cavity walls for filling together with the map and table in BR 262.

j) Interface between walls and doors and windows. Check rebates are now recommended in the most exposed parts of the country.

k) New guidance points to the need for better attention to detail in exposed areas where level access is provided to support Part M, Access to and use of buildings to ensure adequate provision is made for resistance to moisture.

l) Former Requirement F2; Condensation in roofs, has been transferred to Part C as it deals with effects on the building fabric rather than ventilation for the health of occupants.