Sorry, I asked this question before, just wondering if there are any new thoughts. Thanks

I have a question about removing a subfloor/primary floor that extends under framed walls. I can use a circular saw to cut out around the perimeter but this leaves a 2 to 3" edge that the saw can't get at. I could also use a reciprocating saw/multi-tool to make the cut right up to the sole plate.

Can either method be used? It seems to me that in some of the research I'm doing that plenty of people are doing it either way. I was interested in knowing if there is a "structural" reason for doing it one way or the other.

For example, is it better to leave some floor extending out from the sole plate so I can reinforce it with some blocking and tie it in to the new floor? Is there a valid construction practices reason for doing this?

This method does present an issue, though, as the new subfloor will probably be 3/4" and the existing floor is 5/8". That means there will be a need to build up the perimeter with 1/8" slats.

As always, your thoughts and suggestions are appreciated!

 

A carpenter has designed a circular saw just for this purpose that can cut with zero clearance to the wall plate. Unfortunately it is $600 bucks:

CUZ-D-SFS85 | Acme Tools

I usually use a recip saw. Takes a bit of care over top of joists but is otherwise straightforward.
I generally install blocking either way.

 

I usually just cut as close as I can with my skil saw and then replace the floor with same thickness plywood .... unless the rot extends under the studs. What type of floor covering do you intend to use? If tile, you may need to add another layer of plywood in which case I'd stick with the 5/8" and then laminate over it with 1/2"

 

Or just use a cheap toe kick saw... $70 or less at Northern Tool or Harbor Freight.

 

I want to put ceramic/porcelain tile down. It's a smallish powder room (3' x 7') so I want to use the biggest tile I can find so I have very few grout lines to deal with. There is currently 5/8" osb down and I believe a 3/4" plywood would be better suited. Cutting out the existing subfloor leaves that band around the room that is 1/8" lower. I could just build it up with some 1/8" slats and be done with it. I'll try a combination of oscillating and reciprocating saws to cut out the floor.

 

I use a Toe Kick Saw then finish the inside corners with a sawsall with a short wide course tooth blade.
An occilating saw would take to long and fill the room with smoke.
I'd be using T & G Advantech subflooring not plywood.
It's stronger, has a lifetime warranty, no voids, never going to delaminate.
Home Depot rents a Toe Kick saw.

 

Just don't use one of these This is very unsafe, and is meant as a warning not to modify any saw for a purpose for which it was not intended.

 

Just remember that interior walls that are parallel with your floor joists may be sitting on that subfloor. Cut out the subfloor and the wall might just be hanging suspended in midair. You might need to add blocking between joists.

 

Larry, I've done some sketchy stuff over the years but that saw is scary!!!

 

Yeah, you lean your finger just a little too much and it will bite you. It is not mine, for sure, just a picture posted on a goofy site, that caused me to cringe.