Since I don't have a Crain undercut saw, I was going to use my circular saw to cut back my drywall for an expansion space. It would cut about 1.5" above my current underlayment, which was already beefed up. This would result in cutting the drywall well above the sole plate. Is this OK?

I'm a little concerned because then the drywall does not have support on the bottom but it still seems pretty solid. If I rent a Crain undercut saw I could set it at 3/4" and it would cut right at the sole plate, which probably doesn't make much difference.

Thanks

 

I used a Sears brand Rotozip type tool and a free sample piece of hardwood floor from HD as a height guide. It is only drywall after all.

Its slower going than the right tool. Just be prepared for a lot of dust. Keep the shopvac nearby. Did I get enough brand names mentioned?

 

Good idea, DIMMike. But did you use the drill bit type drywall cutter or some special circular blade? The drill bit type cutter would require laying the tool on its side, right? And wouldn't it have to be laying on the floor (or lower) to keep the bit from cutting too high? I'm confused as to how you used a sample piece to keep the bit at the right height.

Alex, there's a Crain undercut saw on eBay for $200. Expensive, and probably more than it would cost to rent one. There's also another interesting undercut saw listed (search on "undercut saw") that looks like a jigsaw stood on its nose with a special flat blade attached. Makes me wonder if someone doesn't make such a blade to fit any jigsaw.

Ray

 

Alex; Check out the local tool rental store. You might be surprised at how little the right tool cost for a few hour use.

At least I hope you will.

 

Thanks guys,

The undercut saw is about the only tool I don't have. I tried to install my first floor with only a circular saw and a hand miter box. I probably threw away enough prefinished long strip on that install because of bad cuts to pay for a power miter saw.

So, lesson learned - I'll get the Crain.

 

If your just cutting the dry wall, put a small masonry cutting disc on an angle grinder and have at it. Lay the blade flat on a 2x(1½"), but to the side so the blade arbor isn't in the way. Push the 2x against the arbor to guide you down the wall, as you hold the angle grinder. It is pretty easy. The hard part is holding the shopvac hose so you catch the dust. Sometimes it looks like I'm playing "twister"