Vapour Barrier Flat Warm Roof

The notion behind a vapour control layer is to install it on the room side of the insulation so it stops the passage of warm moist air entering the structure.

Vapour barrier flat warm roof. Flat roof vapour barrier materials when constructing a flat roof there are two types of materials commonly used. The need for use and design of a vapor retarder in the design of a roof system used to be a hotly debated topic. Discussion in roofing and guttering started by sam85 21 jul 2017. The roof is an unventilated warm roof design finished with a single ply membrane.

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. The vcl is easier to maintain in a warm roof construction as it s generally out the way of the dangers of plasterboard fixings and downlighters. 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. A flat roof vapour barrier such as iko s mvp modified vapour protector offers appropriate moisture protection. Condensation is generated when warm moist air rises and condenses into a liquid on contact with the cooler areas above the insulation. Warm deck flat roof vapour barrier.

Bituminous vapour retarders asphalt mixed with felt or fiberglass or non bituminous vapour retarders plastic. Often the vcl in a warm roof is bonded to a timber substrate which helps the integrity however in a warm roof the vcl has two important functions. 22 jan 2010 messages. 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.

It has transpired that there is no vapour control layer fitted.