If it’s that rough, then use something like the Quickrete Quick Setting Cement or the Sikacyl Ready-Mix Concrete patch. These are polymer-modified cement repair products and can be troweled on fairly smooth. Just be sure to give them a couple days to cure and for the moisture to escape. The Rust-Oleum Concrete Patch Repair is a 2-part epoxy. It’s a great repair product for small pitting and cracks, but it’s more expensive for the amount you will need.

Hi Janelle. Stem walls that are not consistent are typical of garages these days. The stem walls that stick out an inch or two tend to be outside walls. The ones where the drywall runs flush or overlaps tend to be interior walls, but not always. Some people use wood trim to cover the gaps, some use cove molding if the wall does not stick out, others just leave it as is. It requires being creative.

Polyaspartic coatings for DIY application are not the easiest to find. Many only have a 20 minute pot life and cure too fast for the inexperienced. Also, buying products separately for a full color flake application is more expensive. Garage Flooring LLC has a great 250 sq. ft. full flake epoxy system we can recommend. You can find it here. It uses two coats of polyurethane for the clear coat. Also, stem walls use much more material than the floor due to how rough they are. So we recommend increasing the square footage by 50%. When doing a full flake application on stem walls, we recommend mixing up a small batch of the required materials to do the stem walls first since they are time consuming. Once the flake is tossed on them, you can sweep up the flakes that have fallen to the floor and then begin the process of coating the floor. The clear coats can be applied to the stem walls and floor at the same time.

Outstanding, thank you!

The gap between the drywall and the stem wall had orange foam (fire block I’m assuming) spilling out that I shaved to make it flush, but it is definitely unsightly. The top of one stem wall is visible, about an inch wide. It was easy to shave the foam there, but the top of the wall is exposed and ragged in places. I thought about a piece of PVC molding there, but I don’t think the ragged stem wall top will allow the molding to be flush. Any other ideas to hide the unsightly foam gap? The other wall has drywall hanging OVER the stem wall, so the solutions to conceal that gap are different. I was going to cover the gaps prior to using my epoxy system so bits of foam won’t fall during my application.

I have not decided on what to use yet. I keep looking at the primer-epoxy-full flake-polyaspartic top coat high solids kits, but am wondering if each component can be purchased separately to save costs. I haven’t found that combo yet. And many 1 car garage kits would make me nervous in terms of coverage, although my townhouse garage is only 218 sq ft, including the stem wall surfaces. All suggestions and thoughts are welcome. It’s one of those projects where it’s not easy to just start over if you screw it up on the first go, like painting!

Much appreciated!

Hi Janelle. Good for you! There is quite a bit you can accomplish on your own. This includes applying a good quality coating depending on your budget. I will answer your questions by the number.

1) The “crack” around the perimeter isn’t an actual crack. It’s called an expansion joint. The garage slab is typically placed separate from the foundation for the home. This joint protects the slab and the foundation from damage when the concrete expands and contracts with temperature. Yes, let epoxy on the edge run into the joint to cover the rounded edge. After the coating has cured, you can fill the joint with a self-leveling polyurethane sealant such as SikaFlex or similar. We have an article the explains the differences between expansion joints and contractions joints, including what type of materials should be used to fill them.

2) This is called a stem wall. It looks rough because this is where the concrete came up against the wood forms when the concrete foundation was placed. The holes are air pockets that formed up against the board. There is no need to grind or spend a lot of time prepping the surface. It’s rough enough that the coating will adhere. Plus, you won’t be walking or driving on it (hopefully) so optimum adhesion is not necessary. Drag a chisel or back of a hammer across the surface to remove any loose or weak concrete. There shouldn’t be much. Sometimes it needs to washed down to remove old dust and debris that has collected in the holes. Use a brush to apply the coating. Just don’t go too thick or it will slump.

3) It’s very rare for the concrete in a garage to be evenly flat across the surface. There will always be a few shallow spots here and there. If you are grinding or have a small grinder available, grind those areas to remove the roughness.

Lastly, if you want a coating that will last years, do not apply a home improvement store product such as EpoxyShield or RockSolid. Use a quality, higher solids epoxy or polyurea system. We can point you in the right direction if you haven’t decided on what to use yet.

1) I STILL don’t understand what to do with the crack around the entire perimeter of the garage. I don’t know the correct terms, but the garage has about 4 inches on vertical concrete on each side – I’m assuming that’s the foundation? Anyway, is that the crack that I should clean, let the epoxy run into, and caulk afterwards? If so, what product do I use?

2) That vertical part of the concrete has a lot of concrete splatter that I’ve been chiseling off. But there are plenty of random holes in it, some the size of a pencil eraser and deep appearing. If I want to coat those vertical areas with epoxy and flakes, do I need to repair the surface? It’s also hard to maneuver with an angle grinder – how would I prep it before proceeding with epoxy?

3) I have no floor cracks, but some shallow rough areas that I wouldn’t even call chips in the concrete. It’s just not flat like the surrounding concrete. What do I do with that?

Thanks for your patience.