Flat Roof Condensation Risk

For a flat roof construction be it a cold roof a warm roof or a warm inverted roof the calculation method for year round condensation risk set out in bs en iso 13788 known as the glaser method is almost always sufficient.

Flat roof condensation risk.

The cold deck solution. To that end the standard lists three acceptable scenarios for the placement of flat roof insulation. There are two forms of flat roof construction which can reduce the risk of condensation forming. Because the waterproofing layer constitutes a vapour control layer on the cold side of the insulation there is a high risk of harmful interstitial and surface condensation on the underside of the deck or the upper surface of the.

However doing so increases the risk of condensation forming on the elements not surrounded by insulation such as cold roof decks. Cold roof warm roof inverted roof. Check it isn t interstitial condensation. Flat and low slope roof designs to avoid moisture condensation problems flat roofs call up a whole new breed of building moisture problems how to avoid moisture traps under flat roofs avoid mold rot caused by moisture trapped under un vented flat roofs questions answers about the cause cure prevention of moisture problems in flat roofs and similarly hard to ventilate structures.

Designers should therefore take a cautious approach and adopt fail safe solutions. As long as the roof accords with good practice then a more complex calculation method should not be necessary. Nowhere does it support the design and construction of hybrid roofs. A flat roof should be designed to minimise condensation and a condensation risk analysis should be undertaken taking into account positioning of insulating materials vapour control layers ventilation thermal insulation and the choice of materials.