Flooring
 

Looking at installing laminate flooring. Removed carpet, noticed underlayment is OSB Or particle board, (not sure) and is not level in some areas. Can I put 1/4" underlayment plywood on top and then use self leveling compound on the 1/4" plywood.

How off are you talking? Like golf ball rolling by its self if you place it in the floor?

Particle board and OSB are two different animals OSB is safe to use particle board isn't.

Flooring
 

If I placied a golf ball on the floor, it would roll. Looks like a couple of floor joist are higher or bowed. Pretty sure it's particle board with 1/2" plywood subfloor.

Any chance on pulling it up to the joists then sister the joists to level?

Hi guys,

You need to figure it out and give a definite answer. Got a pic?

There's several way to go as Jet is eluding to. Depending on the details you might be able to go the easier way. Need to know about the underlayment. How far out of "flat" the floor is. Level isn't as important as flat. It also depends where within the room and as compared to an adjacent area the hump/dip is. Please describe in more detail and post a pic of the underlayment if possible.

Jaz

Flooring
 

I will have to look into it further, have to work this weekend. Need to look under house at the floor joist to see if they are bowed. The problem seems to be bottom floor at the stairswell going upstairs. The floor joist spans are 13' , 16" on center and are 2x6. The floor is a little bouncy, may have to beef up flooring. Thanks for the info. Will post again later with what I find.

There's no way your joists are 2x6 & span 13', I can tell from here.:wink: If they are, your floor would be more then a little bouncy. Check it out and measure the span accurately to the inch.

Jaz

I don't think I have ever seen a particle board sub-floor seems like it would be horrible it doesn't hold screws or nails well, but I guess it could have been glued. Jaz if it is particle board and it had padding and carpet on it is it possible the humps could be where something was spilled on it and you know the way particle swells from moisture and then don't go back to shape. Could this be the problem. Let me correct something I have seen particle board subs, they used them in mobile homes and if they got wet they were a nightmare. Just a thought.

In my area, some of the homes built in the 70s-80s had particle board subfloors. They are a nightmare. They are full thickness (the 3/4" is really 3/4") so it's not easy to patch with plywood or OSB. The builders should be shot.

Rusty do you think moisture could cause this problem then?

Possible, but may just be settling of the floor joists. Hard to be sure without seeing it.