C e r t a i n Te e d The SMART Vapor Retarder & Air Barrier Film Air Barrier Installation Instructions for Wood Framing
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.
Required Materials The following materials should be used to create the MemBrain™ Air Barrier System: •M emBrain™ sheeting available in 8' 3", 9' 3", 10' 3" and 12' 3" widths, 100' lengths (2,515 mm, 2,819 mm, 3,124 mm and 3,734 mm widths, 30.48 m length • Recommended Sealants: Acoustical or silicone-based sealants conforming to ASTM C 920 or C 834 specifications. • Recommended Tape: Canadian Construction Materials Centre (CCMC) evaluated or other code approved sheathing tapes.
MemBrain™ Air Barrier System Details Acoustical and Silicone-based Sealant Application at Sheet Terminations – Figures 3 and 4 • Use a combination of staples and recommended sealants to attach MemBrain™ to the top plate, bottom plate and end studs. • Place a 1/4 inch to 3/8 inch bead of sealant over the stud surface. • Place the film over the sealant without tension and lightly press to ensure complete contact.
Penetrations – Figure 6 through 11 • Building envelope penetrations include windows, doors, dryer vents, bathroom exhaust fans, electrical outlets, gas lines, plumbing, etc. (See Figure 6) • Cut and fit the MemBrain™ sheeting tightly around the penetrations. (See Figure 7) • Seal the film around all electrical, HVAC and plumbing penetrations with recommended sealants or sheathing tapes. Exhaust Vents Chimneys Plumbing Penetrations Windows Electrical Outlets Figure 6: Building envelope penetrations.
Window and Door Treatment – Figures 7 through 10 • Cut the MemBrain™ sheet to fit the rough opening. • Slit the film at the corners. (See Figure 7) • Apply recommended sealant between the film and the window frame. • Staple through the sealant to the window head, jambs and sill. Seal the window to the rough opening with recommended sealant. (See Figure 8) • Apply recommended sealant between interior finishing material (typically gypsum board) and the attached MemBrain™ sheet.
Large Circular Penetrations – Figures 10 and 11 • Trace the penetrations circumference on a separate piece of MemBrain™ sheeting. • Cut a square piece of film with a minimum 6 inch clearance from the penetration outline. • Intersect the circle with four diameter lines. (See Figure 10) • Cut according to these lines towards the circle’s perimeter. • Place the square patch over the penetration. (See Figure 11) • Seal the cut edges to the penetration with recommended sheathing tape.
Electrical Outlets – Figures 12 and 13 • Wrap and seal electrical boxes using recommended sheathing tapes and sealants. • Airtight plastic boxes are recommended. Wire seal Airtight seal (Box gasket) Seal MemBrain™ Sheeting to outlet box using recommended sheathing tape Caulk wiring penetration at outlet box Seal MemBrain™ SVR Sheeting to outlet box using recommended sheathing tape Figure 12: Sealed interior electrical outlet. Figure 13: Airtight electrical outlet box.
Air Barrier System Continuity – Figures 15 - 18 • Maintain air barrier system continuity at wall, ceiling, floor and foundation intersections. Use recommended sealants. Seal between framing and film overlaps. • Coordinate installation details with framing and insulation trade contractors. • Insulate rim and band joists with fiber glass insulation batts wrapped or pillowed with MemBrain™ sheeting.
Structural Sheathing Wood Stud Cavity Insulation Interior Partition Wall Framing Sealant Wall Bottom Plate Vapor Permeable Exterior Air Barrier Floor Decking Band Joist Figure 16: Detail A – MemBrain™ Air Barrier System interior partition intersection details.
Cavity Insulation Sealant Wall Bottom Plate Insulation Sheathing Floor Decking Structural Sheathing Floor Joist Pillowed Insulation Batt Vapor Permeable Exterior Air Barrier Rim Joist Sill Plate Sealant Foundation Cavity Insulation Figure 18: Detail C – MemBrain™ Air Barrier System Foundation wall intersection details.
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