Roof Vapor Retarder

The need for use and design of a vapor retarder in the design of a roof system used to be a hotly debated topic.

Roof vapor retarder.

Sopra vi is a bitumen coated base sheet for use in approved built up roof assemblies. 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 penetrations and is tied to the wall air barrier. It appears now when vapor retarders are needed more than ever the design community seems to have lost interest which is not good considering how codes and standards altered through concerns for energy savings have changed how buildings are designed constructed and operated. The topside and underside are.

Gaf sa vapor retarder is an sbs modified bitumen vapor retarder for use in approved gaf roof assemblies. Gaf sa vapor retarder is composed of a proprietary formulation of elastomeric styrene butadiene styrene sbs polymer modified bitumen in combination with a high tack self adhesive. A vapor retarder is a material or system that is designed as part of the roof system to substantially reduce the movement of water vapor into the roof system where it can condense. Typically a vapor retarder has to have a perm rating of 1 0 or less to be successful.

Everyone knows that water in roof systems is never a positive. This eliminates the need for a separate air barrier that could potentially prevent the moisture from escaping.