Uneven concrete floor for lifting platform question.

[sugapablo]

OK, people....tips please...

I want to cover an 8'x8' space in my basement floor with two layers of plywood (OSB on bottom, something better on top) for a lifting platform.

The concrete on the floor is VERY uneven and warped.

Not wanting to level the entire basement floor, is there any leveling I can do over just that 8x8 space so the plywood will lay flat?

Self leveling concrete wouldn't work because it would need to be contained in that space, correct? Expansion tape isn't permanent and square edges of SLC would crumble, right?

Also, I don't want anything to add too much height because of the basement ceiling, ideally.

Any suggestions?

[manveer]

I used self leveling concrete in an 8x8 area. I used a frame of 2x4s around the perimeter and then put plastic sheeting down in the area because I'm renting. Poured SLC in there. It works fine.

[sugapablo]

Sounds OK. I'm confused over why the plastic? It it between the SLC and the floor? What's that for?

[sugapablo]

OK, got it. Thanks!

[MBasic]

Sounds OK. I'm confused over why the plastic? It it between the SLC and the floor? What's that for?

The SLC he poured won't bond to the existing concrete . . . he's renting . . . he can demo it and remove it.

Veer: did you leave the 2"x4" outer frame in place?

[MBasic]

He did

Yeah, I was gonna say . . .

If the (thin) SLC was to crack, it wouldn't really matter if the frame was left there. . . frame would keep it from spreading . . .maybe

Did you guys use any rebar? or wire mesh?

[manveer]

Didn't use anything. Thought about wire mesh though. One of the corners under my platform got filled in a little low. Ran out of SLC. That corner got a little uneven after about 2.5 years of deadlifts there. Otherwise the rest of the platform is fine.

[Jeff Illingworth]

I did this in my garage. The self leveling compound has worked fine. In retrospect, I would rather have just done the entire floor instead of the area I lift in - but, hey, I'm cheap.