In a low slope roof assembly the vapor retarder is normally installed under the primary roof insulation.
Roof vapor retarder.
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.
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.
A vapor retarder is commonly installed on the warm interior side of a roof or wall.
Everyone knows that water in roof systems is never a positive.
The need for use and design of a vapor retarder in the design of a roof system used to be a hotly debated topic.
The topside and underside are.
This eliminates the need for a separate air barrier that could potentially prevent the moisture from escaping.
Typically a vapor retarder has to have a perm rating of 1 0 or less to be successful.
Sopra vi is composed of a proprietary formulation of bitumen and is reinforced with a high quality random glass fiber mat.
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.