Vapour Control Layers Flat Roofs

A vapour control layer or vcl on a warm flat roof sits between the roof decking and the insulation.

Vapour control layers flat roofs.

Vapour control layers are normally considered essential under insulation in warm roof constructions to reduce the risk of condensation. Time and time again i see the wrong vaper control layer being used and installed incorrectly. What is the difference between a vapour control layer and a breather membrane. Bs6229 2003 gives advice on vapour control layers in flat roofs and the control of condensation within the building generally.

We offer vapour control layers suitable for use in ceiling wall window and roof applications timber frame constructions behind vertical cladding and within metal profile clad industrial buildings. The answer to keeping timber framed walls and roofs dry is to use a layer to restrict the flow of moisture but not to try and stop it. A vapour control layer helps you shield your building from the consequences of condensation condensation is generated when warm moist air rises and condenses into a liquid on contact with the cooler areas above the insulation. Using a vapour control layer to control condensation.

In this case you need to lay a full vapour barrier on top of your flat roof deck before you lay the insulation and your flat roof covering. The notion behind a vapour control layer is to install it on the room.