Garage floor pitting is one of the most common problems you will encounter if you have a garage in your house. In this post, I’ll go over a few ways that you can try to prevent concrete pitting, because as we all know, preventing the problem from occurring in the first place, is the best way to go. However, sometimes pitting is unavoidable due to issues with the original concrete pour.
Generally, garage floor pitting occurs due to a combination of moisture, freezing temperatures, and rapid thaw cycles. It’s no different than all those potholes you swerve to avoid in the winter time. When water freezes, it expands. When that water has settled into a puddle on your garage floor, it expands and leads to pitting.
There is little you can do in an unheated garage (in northern climates) to take freezing temperatures out of the equation – just one more reason to convince your wife that you should heat the garage too. So, if you don’t have a heated garage, there is one tool that will be your best friend during the winter. This one tool is an absolute requirement, especially for garages that have freezing winters.
The floor squeegee is your best weapon to combat garage floor pitting. Keep your floor squeegee handy and periodically push out puddled water from melted snow. If you know that sub-zero temperatures are coming – get the water out and off of the garage floor. Sub-zero temperatures are very often followed by rapid warming, and these conditions are the perfect recipe to cause garage floor pitting.
Now that I’ve given you a somewhat long-winded explanation of what causes garage floor pitting, and a few ways to prevent it, let’s get to the repairs…
Repairing Garage Floor Pitting
If you have a troublesome area with extensive pitting, you need to start by removing as much loose concrete, aggregate, and dust as possible. Start off by using a stiff wire brush from the hardware store. You need not apply any soap, water, or cleaner at this point; scrub with a dry wire brush.
Now, with as much loose material removed from the concrete, find any raised areas in the pitting that are firmly in place… You’re going to want to remove these areas too. Using a chisel and hammer, tap away as many of these raised points in the pitted area as possible. You do not need the surface to be smooth, and you’re not going for perfection here. Most of these raised points should break away with little more than pressure, and possibly a tap from the hammer.
Get your wire brush out again, and repeat a dry brushing of the pitted area. Now, using a shop-vac, vacuum up as much concrete dust and loose material as possible.
At your local hardware or home improvements store, purchase a concrete bonding primer/adhesive (many of these products will indicate right on them that they can be used for garage floor pitting repairs). I have often found these products in or near the paint or concrete sections of the store. You will also want to purchase concrete patching material. I have seen premixed products, and I have seen mix-it-yourself products… Both work equally well when prepared as directed. One last thing, if you don’t have a trowel, be sure to pick up a finishing trowel while you’re there.
Apply the concrete primer or bonding adhesive to the entire pitted area of concrete. Be sure to follow all of the manufacturer’s directions as closely as possible. You will most likely need to allow the product ample drying time prior to applying the patching material.
With the bonding material ready, it is time to fill the pitted area with the concrete patching material. Apply only as much patching material as needed (or just a bit more). Now, use a 2×4 to screed off any excess patching material (be sure to not let the removed material dry on your garage floor!). Using your concrete finishing trowel, smooth over the patched area of concrete. You may want to sprinkle a small amount of water (small amount) over the patched area to make smoothing easier.
Your patch will usually be fully dried and cured within 48 hours. Keep all car and foot traffic off the patched concrete for at least that long. Even when fully cured, you will most likely see a difference in concrete color where you patched that garage floor pitting; unfortunately, there’s not much you can do about that (a good excuse to convince the wife that you now want to apply garage floor epoxy).
To wrap up, garage floor pitting sucks, but sometimes it is something you cannot prevent. You should now know what to do to repair it.