Well, my first post and it's a doozy. Had to go on the internet to see if any experts have ideas of what to do......here's my situation.
We recently bought a home and we are renovating the basement. The basement floor is unlevel and uneven. Certainly you want some slope towards the drains, however this slope is a little drastic, 3-4" in a 14ft span.
So we ripped out the basement carpet and discovered there is a subfloor put down. There are 4x8 sheets of OSB T&G sitting on Delta FL. The OSB is tapcon screwed to the cement slab. In some spots it looks like the person attempted self leveling cement on top of the OSB. There are signs of the self-leveling cement cracking and crumbling.
We would like to have a laminate floor installed.
Can I put something on the OSB to make the entire room (14x17) even with a little slope towards the drain?
I am concerned about height as well as the ceiling is low...6'3" below bulk heads.
What you have there is all wrong and you should consider removing it down to concrete.
People keep trying to install wood sheets over slabs thinking the laws of natural, (moisture) will not apply to them. The new floor might even look fine for years, but in actuality the wood is shrinking and expanding all the time. If the covering is carpeting of certain vinyls, there may not be any visual problems. But the wood is absorbing moisture to some extent. If there's enough dampness, you're creating an unhealthy science experiment.
There is no "approved" method to correct the drastic slope without installing a new pour of cement. You may want to research Dri-Core as a base. But It won't take that much slope away, and I wouldn't use it unless the basement is very dry using a moisture testing method for several seasons. Remember, a damp slab will look dry when it's not covered with something cuz the moisture can evaporate. That won't happen when it's covered.
TILE GUY - retired- TROY, MI - Method & Product suitability consulting.