Installation Guide

2 CertainTeed Corporation, Building Science Department
In addition to performing as an interior vapor retarder, MemBrain
™
the Smart Vapor Retarder may be installed as
a continuous, interior air barrier system over unfaced fiber glass or other insulation requiring a separate vapor/air
barrier. MemBrain
™
is recommended for interior vapor retarder and air barrier applications, located at the “warm
in winter” (moderate to high heating climates) side of the building envelope. MemBrain
™
sheeting is not intended for
exterior applications where it would be exposed to the elements or UV light.
General Instructions
MemBrain
™
sheeting may be installed as an interior air barrier system. Install large sheets using recommended
fasteners, tapes and sealants to achieve air barrier continuity with the building envelope components, as illustrated
in Figure 1.
The most effective time to install the MemBrain
™
Air Barrier System is:
• After all building envelope penetrations are complete (i.e. plumbing lines, electrical outlets, exhaust vents,
lighting xtures, etc...) and vertical penetrations through wall plates in cavities are appropriately sealed.
• After all windows and doors are installed, and rough opening gaps are sealed appropriately (i.e. with code
approved low expansion foam).
• After wall systems are insulated with unfaced ber glass insulation.
• Before exterior walls and ceilings are nished with gypsum board.
Figure 1: Maintain air barrier continuity at rim joists, corners, partition wall interfaces and ceilings.
Ceiling Joist
Wall Top
Plate
Wall
Bottom
Plate
Vapor
Permeable
Exterior
Air Barrier
(Coordinate
installation with
the framing
contractor)
Cavity
Insulation
Rim Joist
MemBrain™
Sheeting
(Air Barrier/
Vapor Retarder)