Flat Roof Insulation Vapour Barrier

Flat roof vapour barrier materials when constructing a flat roof there are two types of materials commonly used.

Flat roof insulation vapour barrier.

If the roof is insulated with foil faced insulation blankets the aluminium side can serve as a vapour barrier at the same time. However note that one should seal the seams here as well. 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. The notion behind a vapour control layer is to install it on the room.

Bituminous vapour retarders asphalt mixed with felt or fiberglass or non bituminous vapour retarders plastic. A vapour barrier will then need to be installed to reduce condensation in the roof structure. A vapour control layer or vcl on a warm flat roof sits between the roof decking and the insulation. 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.

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. We are insulating a flat roof with tapered rigid insulation over a moisture barrier and then capped with modified bitumen. The insulation and vapour barrier can be mechanically fixed using fasteners and washers or a self adhesive vapour barrier such as alutrix can be installed with insulation bonded on top using pu adhesive battens. Next to that you may also buy a moisture regulating vapour barrier membrane that can manage the damp even better.

However we lose r value where the taper is thinnest and need to insulate under the sheeting.