Warm Deck Flat Roof Vapour Barrier

The architect plans stated requirement for a vapour control layer below the insulation or a 3 in 1 insulation board including vapour control layer and an additional foil backed plasterboard.

Warm deck flat roof vapour barrier.

I was looking to use this vapour barrier from screwfix but not sure if it s suitable for the job it only mentions underfloor heating and laminate flooring in the description. I am having an extension built and my builder is constructing the flat warm deck roof in the following way. This quetion is to do with warm roofs and cold roofs presumably the 50mm of insulation on the underside of joists would act as the vapour barrier if taped sealed correctly or if insulation between joists a vapour barrier i e. A vapour barrier will then need to be installed to reduce condensation in the roof structure.

Discussion in roofing and guttering started by sam85 21 jul 2017. Vapour control layers vcl. I m in the process of building a warm flat roof for a garden room and need to put down a vapour barrier between the sub deck and insulation. This could be a 1000 gauge min polythene sheet.

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. If this has not been done then we would recommend that you install one underneath the joists before the plasterboard goes up. Great videos thanks for sharing. Poly to the underside of joists.

The roof is an unventilated warm roof design finished with a single ply membrane. With any warm flat roof detail such as this a vapour control layer should have been laid on top of the roof deck underneath the insulation. The buildup of a warm flat roof starts with a good vapour barrier followed by insulation then more decking or just the roofing materials depends on if you wa. To use epdm for a warm deck flat roof construction solid closed cell roof insulation such as kingspan or celotex should be placed on top of the roof deck rather than in between the rafters.

It has transpired that there is no vapour control layer fitted. 22 jan 2010 messages. 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.