Spring has arrived and along with it come the ugly results of the winter damage that has been done to the concrete of your garage floor. This is typically due to the deicing fluids and road salts that have been deposited on it over the winter. Now is the time to take inventory of any harmful salt stains that need to be removed as well as spalling that needs repair.
The best plan of action is to understand what causes this winter damage and then take the steps to stop it from progressing We’ll discuss the best way to clean up or repair your concrete from the damage left behind as well as how to protect your garage floor.
How deicing fluids damage your garage floor
When it snows, road crews typically use various forms of liquid magnesium and calcium chloride (road salt) to de-ice the roads. The application of these products essentially melts the ice and snow with the intention of keeping it from refreezing. The problem with this is that it tends to attach itself to the bottom of your vehicle where it eventually gets deposited onto your garage floor.
These deicers create a liquid brine that seeps into the pores of your bare concrete instead of freezing on top. Once this brine is diluted enough to become ineffective or when the temperatures drop low enough, it refreezes inside the pores of your concrete, thus expanding and slowly breaking it apart. This cycle can happen over and over again during the winter. The result of this broken concrete is what’s known as spalling.
Even if road deicers are not used in your town, water that works its way into a more porous garage floor can still freeze overnight and slowly cause the same kind of damage.
Another nasty side effect is subflorescence. This is caused when the moisture in your garage floor finally evaporates and all the salt left behind recrystallizes in the pores of the concrete. This causes areas of your concrete to flake off or spall. It also leaves behind those ugly white stains on the floor.
Repairing winter damage and salt stains
The first thing you want to do is clean your entire garage floor to expose any damage and highlight any salt stains that you may have. Once clean, removing the salt stains off your garage floor isn’t too difficult if you use some elbow grease and know what to use. Rinsing with just water will not work effectively. The key is to mix up a solution of 1 gallon of warm water to 1 cup of vinegar with a squirt of dish soap.
Pour the solution onto the stains and scrub with a stiff deck brush. Use a mop or wet vac to remove the residue first and then rinse liberally with water. The reason for mopping or using the wet vac (preferred method) is to prevent the salty solution from being dispersed back into the pores of the concrete when you rinse it. This is why just rinsing with warm water to remove salt is not very effective. For particularly tough salt stains it may require another application or two.
As far as good aftermarket products, Salt-Away has been known to work well. It’s very popular for use with marine products and is also used to remove salt from concrete, brick, and masonry as well. It needs to be applied and the residue removed in the same manner as the vinegar solution.
For the most stubborn salt stains, you can use a mild solution of hydrochloric acid. Mix 1 part acid to 20 parts water. This is actually a very mild concrete etch. We have instructions on how to mix and neutralize acid solutions here.
As a note, pressure washers are not always successful in removing salt stains. They have a tendency of driving the salty solution deeper into the concrete just to reappear again.
Once the salt is removed, now is the time to repair any pitting or spalling that may have occurred from the deicing fluids. Polymer modified cements work well for this. They bond much better than regular cement and create a stronger finish that can be feathered much thinner. Regular cement patch will not adhere well to the surface and can chip or break away. You can learn more about repairing spalling and pitting here.
Protect your garage floor from winter
Once you are satisfied with the outcome of cleaning and repairing your garage floor, the next step is to protect it from winter damage in the future.
The least expensive method is to apply a penetrating sealer that blocks deicing fluids from penetrating into the concrete to begin with. You can also use containment floor mats, or apply a good topical sealer.
Also, try to be diligent about cleaning the floor after the latest storm has past to remove any corrosive debris. For more information, you can read about the multiple ways to winterize your garage floor here.
Once you restore your garage floor from winter damage and take steps to prevent it from recurring in the future, you will no longer have to fret over the anticipation of what spring reveals with your concrete garage floor.