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.

This type of roof has normally been used over small extensions to dwellings using timber joists and plywood deck. 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. Nowhere does it support the design and construction of hybrid roofs. The cold deck solution.

There are two forms of flat roof construction which can reduce the risk of condensation forming. 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. Cold roof warm roof inverted roof. Check it isn t interstitial condensation.

We ve been talking to ian dryden business development manager at sig roofing about an increasing concern he has for flat roofs built in the 1980s and early 1990s and incorrectly refurbished roofs which appear to be leaking but they aren t. Designers should therefore take a cautious approach and adopt fail safe solutions. This problem may become more common as existing buildings are altered to become eco friendly. 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.