I’m writing this post as a guy that found a method that works for him, but not necessarily as a guy that knows the best way to approach the problem. So if you have a better method to remove subfloor, by all means leave a comment!
Well I’m just about ready to run the plumbing in my new bathroom but I have a problem: the crawlspace below the bathroom is completely inaccessible thanks to a foundation wall on one side and a large heating duct on the other. Add to that the fact that there are parts of the crawlspace where my ample derrière just wasn’t designed to fit without several months of a serious eating disorder. (Next month: The Boring Homeowner Guy on How he Beat Bullemia!)
I opted to attack from above by removing the plywood subfloor. This will also give me a chance to ensure that everything is level from the joists on up, something that’s never a guarantee in an old house like mine.
You’ll only need a few tools to tackle this job:
- A circular saw with a ripping blade, preferably one you don’t particularly cherish.
- A drill or impact driver and appropriate bits if your subfloor was installed with screws
- A hammer
- A small pry bar that you can handle with one hand (“15 inches is a good size,” said no woman ever)
- A large ripping/wrecking bar
First things first: if there is any plumbing or wiring coming up in the sections of subfloor you plan to remove, deal with them now. Go ahead, I’ll wait.
Separate Sections of Subfloor
The basic approach is to cut the subfloor along the grooves between sheets. Most plywood and OSB subflooring is tongue and groove, which means that one edge has an open gap through it’s center, and the opposite edge has a protrusion that fits directly into it. This provides additional stability, eliminates air infiltration, and allows expansion and contraction of the subfloor as a single unit. It also means that if you skip this step, you’re an idiot.
As I said above, don’t buy a brand new saw blade for this task, and don’t think it’s not going to be a little bit duller after the fact. Your chances of hitting a nail are two are pretty good.
Pry Up Individual Sections
Depending on the method used to install your subfloor this step could be a breeze or it could be slightly less serious than El Nino. If you’re lucky your subfloor was installed with screws, in which case you can reverse the bulk of them out and lift the subfloor out with little effort. If your subfloor was nailed, this is the method that I found worked best for me.
Using your hammer and small pry bar lift up a corner enough so that your larger prybar will fit under it. Rock the prybar in progressively larger motions so that your subfloor doesn’t crack, but you should start to hear nails pop. As nails begin to pop remove them with the hammer or small prybar. Work your way around the sheet in this fashion. Eventually the sheet will have enough flexibility that you can grab ahold of an edge by hand and rock it up and down to pop the nails even more quickly. Using this method it took me about ten minutes to remove a sheet, and it was still in decent enough shape to use for something else later.