Warm Deck Roof Vapour Barrier

Discussion in roofing and guttering started by sam85 21 jul 2017.

Warm deck roof vapour barrier.

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 insulation is immediately below the waterproofing layer. Including fibreglass roof kits torch on felt and liquid rubber products everything you need for flat roofing is in one place. The insulation can be adhered mechanically fixed or loose laid.

A vapour barrier will then need to be installed to reduce condensation in the roof structure. Vapour barrier on warm deck roof. I am having an extension built and my builder is constructing the flat warm deck roof in the following way. This could be a 1000 gauge min polythene sheet.

Discussion in builders talk started by fatpiggy12345 sep 24 2020 at 9 39 pm. Our builders have put a vapour barrier on the upper side of the insulation on a warm deck roof. When we use a vapor retarder in a roof system it will also act as an air barrier as long as it is sealed at all perimeters and. A warm flat roof or a built up roof bur is one where all the insulation is above the joists deck making them part of the warm fabric of the building.

I believe this is wrong as it should be on the lower side warm side. Whether you re repairing a flat roof or laying a new one from scratch you ll find all the materials you need here. Exceptions to this idea include roofs over indoor swimming pools or other high humidity producing activities and over new concrete roof decks to prevent the moisture in the concrete from drying into the roof system. If this has not been done then we would recommend that you install one underneath the joists before the plasterboard goes up.

The vapour control layer is above the decking but below the insulation. Warm deck flat roof vapour barrier.