Flat Roof Vapour Control Barrier

Vapour control layers vcl.

Flat roof vapour control barrier.

There is no requirement for any air gaps. A vapour control layer or vcl on a warm flat roof sits between the roof decking and the insulation. Its not cheap purchasing it by the role and by the pallet load is cheaper but is a considerable layout. Why is it the best vapour barrier for flat roofs.

For all warm flat roofs a fully intact vapour barrier would be required on the room side under the insulation. Provided your vapour control layer is intact then there should not be any risk of condensation. A polythene vapour barrier limits the movement of air and water vapour through a membrane so a vapour control layer is air permeable or vapour permeable. Vapour control layer for a cold roof.

A vapour control layer is designed to catch this vapour preventing it from condensing on the insulation or elsewhere in the loft space or attic. Vapour resistance of 2000 mns g. However the cross ventilation does not completely remove the moisture vapour in the ceiling void and a vapour control layer sealed at joints and penetrations is required under the insulation and over the plasterboard to provide a barrier against moisture vapour rising up from the room below. Comparatively a vapour barrier prevents any movement of vapour or air occurring through the building instead of just limiting it to a controlled level.

At roofing superstore our choice of flat roof materials includes everything you need to create a long lasting weather proof flat roof that performs and looks good too. Self healing if punctured by fixings. 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. Temporarily waterproofs the roof can stay uncovered for up to 3 months.

Bituminous vapour retarders asphalt mixed with felt or fiberglass or non bituminous vapour retarders plastic. A flat roof vapour barrier such as iko s mvp modified vapour protector offers appropriate moisture protection. The notion behind a vapour control layer is to install it on the room.