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.
Flat roof insulation vapour barrier.
Vapour control layers vcl.
A vapour barrier will then need to be installed to reduce condensation in the roof structure.
However note that one should seal the seams here as well.
A flat roof vapour barrier such as iko s mvp modified vapour protector offers appropriate moisture protection.
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.
Bituminous vapour retarders asphalt mixed with felt or fiberglass or non bituminous vapour retarders plastic.
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 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.
If the roof is insulated with foil faced insulation blankets the aluminium side can serve as a vapour barrier at the same time.
The notion behind a vapour control layer is to install it on the room.
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.
We are insulating a flat roof with tapered rigid insulation over a moisture barrier and then capped with modified bitumen.