Sanding down subfloors to get level

[branimal]

I leveled out my sagging subfloor using sleeper shims, and plywood decking. In areas that were less that 3/4" below the high point, I just used sleeper shims.

I'm installing 3/4" pre-finished white oak flooring.

It looks like I screwed up my measurements in one corner of the apartment. I found the high point to be elsewhere in the apartment and now it looks like the high point is in that back right corner of the pictured room. Circled area is high. Most of it is 1/8" to 3/16" too high. In the worst spot its about 5/16" - 3/8" too high. That plank subfloor is white pine t&g. 7/8" thick. really old stuff.

I can think of a few ways to solve this problem:

1. Buy a belt sander and sand it down to level. Or use my R/O sander. That's gonna take a while.

2. Or plane & sand down the backside of the hardwood flooring.

3. Cut out the flooring and replace with thinner plywood.

Any suggestions?

 

[K'ledgeBldr]

Wow! That’s going to be one squeaky-*** floor!

 

[branimal]

Wow! That’s going to be one squeaky-*** floor!

It’s 95% 3/4” plywood deck. The remaining 5% is just sleeper shims. I did that to avoid raising the floor height too high.

I’ve installed hardwood flooring in other areas over just sleeper shims and it’s fine. At least for now. I was worried about that as well.

The floor is dead level. I used a laser level and a target measuring device. So I’m hoping there are no squeak issues over time.

 

[allinon72]

Yeah I mean given what you’ve done so far, pick the path of least resistance, whatever that might be. Doing things by the book is out the window at this point.

 

[PCustoms]

Can you cut a transition at the door to that room and just re-do that room?

 

[like2wheel]

4. Install your flooring, plane the rise off the bottom of the baseboard & forget about it.

Wont be noticable, & when the furniture is in, it'll be forgotten.
Its an old house, these things are expected.


PS, depending on the size of the area, taking it down with a handheld belt sander might be a big ask. And almost impossible with a RO.



.

 

[Red 17]

IMO don't take it out of the flooring.

Take some of it out of the subfloor then see post 6.

We did a remodel and there are a couple places where levels weren't quite right. I hate it that any of it was taken out of the hardwood.

 

[f121]

If it’s just a lump in a few locations, route out a slot on the ply sub floor where it sits over the baton. If it’s an overall trend that puts a 3/8” slope in the floor, ignore it, only people with lazer levels will notice.

 

[paredown]

I've hit high spots with a belt sander when I have had ridges crossing joists/plywood joints. I think if you have a belt sander it wouldn't hurt--but the problem is you can really work all the way into the corner.

I vote for belt sander, plus pull scraper (should work fine on the white pine, get extra blades) to work into the corner, get it close, put down your rosin paper and call it good.

 

[Renegade1LI]

Just recently sold an older home, people love the not so level floors, you're making a lot of unnecessary work for no gain. Just don't finish with a high gloss they'll look great.

 

[The Cobbler]

1/8-3/16 is nothing
5/16-3/8 in that area is nothing to worry about . no one but you will know it's there . just make sure it's not a steep rise, blend it out and it won't be noticeable

 

[dreamingmuscle]

Level quick will make it right in minutes.

 

[pcmeiners]

Only you will be aware of the height differences, give it a few months and even you will not care but....

If you must pursue, I have used a 9" disk sander (auto) with a very coarse disk, cuts down sub flooring fast. If the sub floor is not installed or can be temp removed, I would cut the beams down with the grinder ( to a reasonable degree) than add the sub floor

https://www.homedepot.com/p/Milwauk...VAeOzCh1seADfEAQYCiABEgLcefD_BwE&gclsrc=aw.ds

Reasonable excuse for a new tool.