Cutting through a thick wall
jay443
| Posted in General Questions on
I am interested in retrofitting my house with either a ducted HRV or something like the Lunos e2. Problem is that I have no idea of how to cut through my walls. I have 2×4 walls but last year I re-sided with 4″ of XPS and a rainscreen system. So in total my walls are about 9.5″ thick. How do I cut a 5-6 inch circular hole in these thick walls?
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Replies
You could use a coring bit, but those are expensive. Since a big chunk of your wall is foam, you could try using a hole saw to take out chunks. Run the hole saw until it bottoms out, pull it out, then take the “core” out in chunks using a chisel. It’ll take a while, but you end up with a clean hole. I’ve done this before myself.
Another option is a sawzall, but you’re pretty much guaranteed to get a messy hole that way. I’m not aware of any jigsaw blades long enough to work here, so jigsaws aren’t really an option.
Bill
Jay,
Use a small (something around 3/16"), long bit to drill a pilot hole. Then work from both sides using a 4" hole saw.
These are great ideas, thank you both!
I should have mentioned the long bit and pilot hole Malcolm mentioned. That’s how I keep things lined up when doing my “cut and chunk” hole saw method. I’d commend a long 1/4” but though, since that’s the same size as the pilot bit on most hole saws, and it’s a little more durable and less likely to break while you’re working.
Bill