Foam Board and Spray Foam
tim-x
| Posted in Energy Efficiency and Durability on
Hey,
I’ll be using 2″ EPS against my concrete walls. The stuff I’ll be using us not tongue and groove. I was wondering if I could leave a gap between the boards and Spray Foam in between or should I try to get them as close together and tuck tape them? Also, should I be spray foaming the top and bottom edges as well? Should I leave a gap at the bottom of the floor for spray Foam?
Thanks!
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Replies
Whenever possible, I'd prefer to butt factory edges tightly against each other, rather than leaving a gap for spray foam. I'm not aware of any tape that sticks well to EPS. You can use foam board adhesive (PL-300 or similar) in a continuous bead along the top of the concrete wall, and additional adhesive to seal the boards to each other. Eventually, you'll end up at a corner where you will need some foam to fill in an irregular gap--concrete walls are rarely perfectly square.
Tim,
As Jon implied, EPS can be difficult to tape. Here's my advice: If your EPS panels have a foil facing, butt the panels tightly together and use tape. If your EPS panels are unfaced, leave enough of a gap for the nozzle of your canned-spray-foam applicator.