Flat Roof Condensation Risk Analysis

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.

Flat roof condensation risk analysis.

As long as the roof accords with good practice then a more complex calculation method should not be necessary. 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. A warm roof features a structural deck vapour control layer insulation and waterproofing a tried and tested solution that the industry knows works. Flat roofs are among the simplest construction elements that can feature in a building.

Flat roof refurbishment best. In the above example of a condensation risk analysis the top line t represents temperature and the bottom line d represents the material s predicted dewpoint temperature which varies with the amount of moisture in the air in high humidity conditions a material s dewpoint temperature is increased. 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. This type of roof has normally been used over small extensions to dwellings using timber joists and plywood deck.

This is something we do for all our new roofs as well as part of our design service. The analysis will determine the dew point and you can check where the condensation is happening in the report.