EPS in my basement
tim-x
| Posted in Energy Efficiency and Durability on
Hey,
I’m about to start putting 2″ thick 4×8 EPS on my basement walls and in my rim joists. I was just wondering about clearance. Should I try to put the EPS as close to the floor and floor joists as possible, or should I leave a gap so I can spray it with canned spray foam?
Also, before installing the foam board, I was considering applying quik rite to the small holes where rebar is showing and then applying a water sealer to the all of the basement walls. Do you think this is necessary?
Thanks!
Tim
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Replies
Tim,
Q. "Should I try to put the EPS as close to the floor and floor joists as possible, or should I leave a gap so I can spray it with canned spray foam?"
A. Either way will work. Even if the EPS touches damp concrete, it won't be harmed.
Q. "Before installing the foam board, I was considering applying Quik Rite to the small holes where rebar is showing and then applying a water sealer to the all of the basement walls. Do you think this is necessary?"
A. Unless you have noticed signs of water entry, this step is probably not necessary. But if you are a belt-and-suspenders kind of builder who is kept awake at night by water-entry worries, it certainly can't hurt.
If you get any ground water intrusion via the foundation-slab joint, you might consider elevating the foam a few inches. Missing that small amount of insulation 3'-8' below grade isn't going to cause a lot of energy loss and might improve the chances of that intrusion drying out. If you are doing that, don't spray foam it.
Of course, fix the intrusion problem if you can but that can be difficult and expensive ...