Introduction In addition to performing as an interior vapor retarder, MemBrain™ 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.

Safety note: When installing MemBrain, make sure that you are wearing the appropriate personal protective equipment. The following items are recommended: safety goggles or glasses and gloves.


The following materials should be used to create the MemBrain Continuous Air Barrier & Smart Vapor Retarder System: • MemBrain Continuous Air Barrier & Smart Vapor Retarder - Sheeting available in 8' 4", 9' 4", 10' 4" and 12' 4" widths, 100' lengths (2.44, 2.74, 3.05 and 3.66 mm widths, 30.48 m length) • Approved Sealant/Caulk - Silicone-based sealants - Must conform to ASTM C920 or C834 specifications • Approved Sheathing Tape - Canadian Construction Materials Centre (CCMC) evaluated or other code-approved sheathing tape.


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.
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 fixtures, 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 fiber glass insulation. • Before exterior walls and ceilings are finished with gypsum board. 
1. Staple MemBrain to the bottom of ceiling joists every 12 to 24 inches. 
2. Seal the film to interior and exterior wall top plates using recommended sealants. 
3. Fasten the film using staples through the sealant to the plates every 12 to 24 inches. 
4. Allow the film to overlap at the corners a minimum of 6 inches. 
1. Start at a corner of the room where an interior partition wall or door jamb meets an insulated exterior wall. Lay the MemBrain roll on the floor, with the end touching the bottom of the partition wall or jamb. 
2. Unroll MemBrain along the insulated wall, until the next corner is reached. Cut the film perpendicular to the insulated wall so that the overall length is about 8 to 12 inches longer than the wall. 
3. With the 3-inch offset edge parallel with the top of the insulated wall, place one corner of the cut sheet at the top left or right corner of the wall. The factory-cut edge should be covering the top edge of the top sill plate. The cut edge of the sheet should wrap around the inside corner at least 4 inches. Ensure that the folded material is facing the room (the print across top header will be facing out). Anchor this corner with staples. 
4. Apply recommended sealant over ceiling-overlapped film material at the top plate, to the frame around window and door rough openings and to the bottom plate.
Working towards the opposite corner, pull the sheet tight, and staple the offset edge to the top sill plate through the sealant bead. Staples should be at least 12 to 24 inches apart. 
5. After stapling to the opposite corner, allow the folded sheet to unfold to the flor
 6. Pull the sheet downward and staple through the sealant bead to the bottom sill plate. Then staple at 12- to 24-inch intervals along each stud. Effort should be made to minimize wrinkles along the stud surfaces to make drywall installation easier

you can read all the information and all the instruction  here. https://www.certainteed.com/resources/30-28-137.pdf