Technical Booklet C Site Preparation and Resistance to Contaminants and Moisture·Page 27·6.2
Requirements for walls to resist moisture
Walls must resist moisture passage from the ground and not be damaged by it, and external walls must resist precipitation penetration to both the structure and the interior.
Walls should –
(a) resist the passage of moisture from the ground to the inside of the building; and
(b) not be damaged by moisture from the ground and not carry moisture from the ground to any part of the wall which would be damaged by it, and, if the wall is an external wall –
(i) resist the penetration of precipitation to components of the structure that may be damaged by moisture; and
(ii) resist the penetration of precipitation to the inside of the building.
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