Technical Booklet C Site Preparation and Resistance to Contaminants and Moisture·Page 24·5.13(d)
Damp proof course for suspended timber floors
Suspended timber floors must be protected by a damp proof course made of impervious sheet material, engineering brick, slates in cement mortar, or equivalent material that prevents moisture passage.
with a damp proof course of impervious sheet material, engineering brick or slates in cement mortar or other material which will prevent the passage of moisture. Guidance on choice of materials is given in BS 5628-3.
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