Technical Booklet C Site Preparation and Resistance to Contaminants and Moisture·Page 22
Vapour control layer function and interstitial condensation risk
When the DPM is on the warm side of the insulation, it acts as a vapour control layer and minimises the risk of interstitial condensation forming on layers on the cold side of the insulation.
Where the DPM is on the warm side of the insulation it will act as a vapour control layer (VCL) and minimise the risk of interstitial condensation forming on any of the layers on the cold side of the insulation.
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