Tapes for air sealing between concrete and foam or wood/OSB
Looking for some suggestions on type/brand of tape to use, or whether these applications are even feasible or recommended ….
We have several details where I’m considering using a tape to air seal between concrete and another substrate – wood, OSB, foil facing, polyiso foam, possibly also canned spray foam.
One is at the lower edges of our Zip-R sheathing panels – would like to tape from the OSB front of the Zip-R panel, extending over the edge of the polyiso foam beneath the OSB, and over to exterior of the poured concrete foundation wall. Is there even any tape that can hold up to this kind of exposure? (If not, we’ll just use an adhesive to seal the inner polyiso of the Zip-R panel to the sill or rim joist.)
Another is at the top edge of our foil faced polyiso (Thermax) on the interior of the basement wall. We need to leave a termite inspection strip there. (Thinking I’ll fill in this gap with some small removable pieces of foam insulation later, but the air barrier would run up the front face of the larger Thermax panels, then behind these smaller pieces.) I’d like to stop any potential air infiltration from behind the polyiso. So I’d like to tape from front foil face of the Thermax panel, over the top edge and then up the concrete wall a bit.
Another is at the seam between the lower edge of the Thermax panel and the slab. I’ve received advice here before suggesting that self-leveling polyurethane sealant is the way to seal this seam, but I’m wondering if I couldn’t use tape? Actually, I’ve seen it recommended elsewhere to leave a half inch gap between your polyiso panels and the slab and fill that in with one-component spray foam. So if we do that, the tape would extend from the slab, up along the cured spray foam and on to the foil face of the Thermax panel.
We’ll be using 3M All Weather Flashing Tape (8067) for some other things, and so I’m thinking it might work for these applications as well. Any thoughts?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
William,
My first choice for your sheathing-to-foundation joint would be Siga Wigluv. It definitely sticks to concrete.
I'm not sure whether 3M All Weather Flashing Tape would be as durable in that location. Perhaps a GBA reader will advise you on that.