Vapor Barrier Under Tpo Roof

A vapor retarder is typically installed on the warm interior side of a roof or wall.

Vapor barrier under tpo roof.

That reduction of air and moisture infiltration can then help improve roof longevity. Smooth tpo fleece back tpo self adhered tpo tpo colors extreme tpo. This wall is a further variation of figure 6 but now it has a class i vapor retarder on the interior a vapor barrier completely eliminating any inward drying potential. The vapor barrier protects the roof insulation from the vapor included in the interior air.

In a roof assembly the vapor retarder is normally installed under the primary roof insulation. Most authorities now agree that vapor barriers are important under certain conditions but not necessarily as a whole house solution for every home. A vapor barrier can be loose laid or. About half of our indiana projects specify a vapor barrier under the roof insulation.

Resolution of the vapor barrier debate. For 30 year warranties see the reflexeon platinumand ultraply 080 membrane information. A roof design that includes an adhered roof membrane with multiple layers of insulation with board joints offset and staggered over a vapor retarder air barrier helps lower the risk that air and the moisture it carries will infiltrate the roof system. Typically a vapor retarder has to have a perm rating of 1 0 or less to be successful.

In circumstances where conditions inside a home or office are much different than outdoor conditions water. The warm moist air equalizes to the exterior where the air is cooler and drier. Some debate still occurs over how necessary vapor barriers are but a consensus is growing closer. Applicability limited to very cold subarctic and arctic regions.

Therefore you will often see it installed directly on a roof deck such as a concrete or wood deck or on a. Found in this manual. This vapor if left unchecked can wet the insulation and over time will reduce the r value of the insulation and lead to mold. For roof systems the 2nd law of thermodynamics helps explain why during the cold winter months warm moist interior air e g 75f 50 rh infiltrates up into a roof system that doesn t have a vapor retarder air barrier in the system.

Gaf tpo roofing membranes include. Contact the roof system solutions group at firestone building products for additional information. For any warrantable 20 year ultraply tpo roof system the ultrablend system is an option for wall flashings and details.