floor flatness near walls

[whiskeynitro]

Hello. I will be installing a floating engineered bamboo floor and have a few questions on leveling. I know its more about flatness and there are areas i will need to use a leveling compound or patch where the low spots are 3/16ths or more (not much more).

The flooring will be going upstairs on top of a plywood subfloor.

1) Near some of the walls the floor is sagging down at least 3/16ths. This is within maybe 6-12 inches from the wall that the floor begins to sag towards the wall. I don't see us walking much in these areas right up against the walls. Most of these areas will have furniture anyways. I understand it being flat in high traffic areas but how important is it that the floor be flat right next to the walls?

2) I know the self levelers require a fast working time. Are the self levelers any better than a floor patch that is premixed? I find the pre mix stuff easy to work with as I have already tried it in the hallway. Just curious if one is better than the other in anyway?

The flooring I am installing is 3/8ths thick and about 5+" wide if that makes any difference

Thanks

 

[nealtw]

You want them level or I would anyway. I will question the thickness of the sub floor as it is sagging under the weight of the non bearing walls. That is why the old times ran a joist under the walls, they have only started looking for that here lately.

 

[Sparky617]

What is below this floor, an unfinished basement or crawlspace?

 

[whiskeynitro]

We have a basement below and unfortunately with a finished ceiling but from what I can tell the plywood is 3/4. There are no cracks anywhere along the walls. inside or out and nothing was "covered up". House was built in 1987 and has not been touched since, at least cosmetically. No signs of any repairs or patching. It's a brick home and there are no cracks anywhere along the brick.

There are no sudden drops in the floor or anything and all the plywood looks good just has these low spots along the walls. And it wont be the entire wall just sections. sorry hard to explain, for me anyways.

 

[nealtw]

It sounds like the plywood has sagged a little under the weight of the wall because it happened to land between the joists in the floor. Anything is fixable, but this would be a lot of work and a little destructive. So I think just leveling from above is the way to go. With whatever you are comfortable using I guess.

 

[bud16415]

I would lay a few pieces loose fit just the way it is and walk around on them and see if it is an issue. I threw an engineered flooring snap lock stuff down on our kitchen when we were rebuilding the 150 year old place and I had a good inch or more drop to the center. It formed down quickly and when I set the island on it looked fine.

The little drop you have might not be a problem at all. Are you putting a pad under it? Maybe a double thickness in those spots. At my old house I used upside down shingles in one spot to take out a dip.

You really wont know until you try it.

 

[whiskeynitro]

I did try the loose fit with some pieces locked together and it seemed okay to me. I just wasn't sure if it could cause the boards to weaken since it's not flat. but i figure since we wont be walking on it and the slope ends at the wall it should be okay. But every time I assume something will be okay it's not so I asked

I am using underlayment although not real thick, it is 2mm. I do have some dips to repair in the rooms where traffic will be so since I am doing that anyways I may take care of around the walls. At least in the lowest spots. I tried the shingles in one spot but when i laid the flooring over them it did have an odd feel to it, and noise. Perhaps with the whole floor down it would have been fine but decided on the floor patch. I suppose as I am going if I think a spot is too bad I can double up the underlayment like you said.

Thanks for the responses I appreciate it!

 

[nealtw]

I would do the filling, give the new floor every chance to work.