Concrete floors that slope can be a difficult problem to solve. Paradigm Concrete Finishes gives a full overview of the best way to tackle sloping concrete floors and the easiest ways to remedy the problem. The first thing needed is to figure out how much the concrete is sloping.
If you have a differential of 6 inches, a urethane cement is needed, if the slope isn’t as severe there are other ways to handle it.
Testing the concrete
The first step you should do no matter what, is test the concrete slab to for moisture and also for density. This can be done with a simple moisture kit. Once you do this, you’ll understand if the concrete is good enough to work with or if you will have to use a moisture barrier. If the concrete is crumbling and extremely soft, a urethane cement or ardex concrete mix should be in order. If there is moisture in the concrete, but the integrity of the concrete is fine, then you will apply a moisture barrier coating before applying a final coat.
Grind the concrete
Prepping the concrete is extremely important no matter what you do. The concrete has to be prepped in order to accept any additives. This should be done with an industrial grinder. You can use PCD diamonds on the part of the slab that is higher and literally remove an extra layer of concrete so it is more level. After grinding, you will get a better feel for how much the concrete slopes.
Fixing the concrete slope
There are several ways to fix sloping concrete after you have grinding and sanded the concrete surface. Two options that are commonly used are self leveling epoxy and a urethane cement microtopping. Both of these options will self level and harden making the floor smooth. Both options will now serve as your new surface.
Getting the look you want after leveling the sloped cement
The good thing is that urethane cement overlays are polishable materials so you can make the the floor look like a polished concrete slab after application. This process takes grinding and honing the concrete with 4-6 passes with gradually lighter diamond blades. If you use self leveling epoxy, the standard process is to apply flake or a color coating on top, and then finally a clear top coat on top of the floor.
Conclusion
Through grinding the cement, applying a self leveling epoxy or a cementitious overlay, you can make a floor level. After the floor is level, there are many different decorative options that can be applied.
This article is written by Jeremy Douglas of Paradigm Concrete Finishes.
It was really interesting to me when you mentioned that it can be difficult to repair concrete floors that are sloping. If you need to level out concrete, I would think that it would be a good idea to find a contractor that can perform mudjacking. As far as I know, mudjacking is a pretty common process that is used to repair concrete that is sinking.