Air sealing question
tech1234| Posted inGreen Building Techniqueson
Just wanted to verify my plans here with the experts at GBA. I am in the process of building my “pretty good house” 12″ double stud wall, R20,40,60… dense pack cellulose in the wall, zip sheathing and loose fill cellulose in the ceiling/trusses. (southern NH)
I will be doing weather/air sealing in the framing stage with zip tape/zip liquid/dynaflex 230/froth pack. I was also planning on using pro clima Intello Plus membrane as an air sealer as well as a way to hold the cellulose during install. I just wanted to double check that this system isn’t going to cause a moisture trapping issue in the walls or other negative effect
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Replies
Tech,
Can you tell us your name?
I assume that the Intello Plus will be installed on the interior side of the interior studs.
When building a double-stud wall, many builders prefer to use a more vapor-permeable sheathing than Zip System OSB. That said, your wall will probably work OK, especially if you include a rainscreen gap between the exterior sheathing and the siding.
For more information on this issue, see these articles:
Wall Sheathing Options
How Risky Is Cold OSB Wall Sheathing?
Monitoring Moisture Levels in Double-Stud Walls
How to Design a Wall
The Return of the Vapor Diffusion Bogeyman
Two Views of Double-Stud Walls
Yes, consider using plywood instead of Zip OSB. Taped and covered with Typar WRB and then a gap.
Tech: we installed a membrane attached to the exterior face of our interior stud wall. We cut holes in it for cellulose installation and taped the holes. The interior stud spaces function as a utility chase, avoiding needing to repair the barrier when installing electrical boxes. After rough wiring and plumbing, we installed fiberglass batts.