Approved Document C provides instruction on resistance to contaminants and moisture, including ensuring buildings are protected from both weather and water damage, from dangerous substances such as radon and methane, and that guidelines are followed when preparing a site for construction to take place.
Guidance is provided on preparing a building site and its foundations for construction, detailing precautions that must be taken in advance. Steps must be taken to guarantee new building foundations will not be damaged by pre-existing foundations, vegetation, tree roots or topsoil. Ground moisture must be contained and removed, using suitable drainage pipes to avert damage to buildings. Contaminated ground must be cleared in advance of any contaminants, adhering to health and safety procedures.