Spring has arrived and along with it come the ugly results of the salt stains and winter damage that have occurred to the concrete of your garage floor. These stains and damage are typically caused by the deicing fluids and road salts that have been deposited on the concrete floor. You may have tried multiple times to clean and rinse the concrete, but the salt just keeps coming back.
We’ll discuss the best ways to clean and remove salt stains from your garage floor. In addition, we will include how to make repairs to the concrete that may have been caused as a result.
Lastly, we will discuss how to seal and protect your garage floor to prevent salt intrusion, salt stains, and damage in the future. But first, it’s important to understand why the salt stains return, the damage it can cause, and why you need to stop it from progressing.
Why deicing fluids And Road Salts damage Concrete
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. When the water freezes, it expands and creates small fractures within the concrete.
This cycle can happen over and over again during the winter. The result of this fractured and broken concrete is what’s known as spalling.
Another nasty side effect is the process of subfluorescence. This is an accumulation of water-soluble salts just beneath the surface of the concrete. When the moisture in your garage floor evaporates, the salts left behind recrystallize in the pores of the concrete.
This harmful accumulation of salts (calcium chloride), will react with calcium hydroxide that is naturally occurring in concrete. This reaction creates calcium oxychloride (CAOXY) within the salt. The COAXY crystals within the concrete expand and cause it to fracture and break. It also leaves behind those ugly white stains on the floor.
Even if road deicers are not used in your town, water that works its way into a bare concrete garage floor can still freeze overnight and slowly cause similar damage. It’s just not accelerated with the addition of salt.
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How To Clean Salt Stains From Your Garage Floor
The first thing you need to do is clean the entire garage floor to reveal any salt stains that you may have. As tempting as it may be, do not use a pressure washer. The high pressure of the water will drive the salt crystals deeper into the concrete and make them harder to remove.
Once the floor is clean, removing the salt stains from the concrete usually isn’t too difficult. You need to use some elbow grease and the proper salt cleaning solution. Rinsing over and over with water is not very effective.
6 Step Salt Cleaning Solution
- Mix 1 cup of vinegar with 1 gallon of warm water and then add a squirt of dish soap.
- Apply the vinegar solution to the salt stains and let it sit for 5 minutes to penetrate.
- After 5 minutes, add a little more solution and scrub the stain with a deck brush.
- Use a wet vac to pull the salty solution out of the concrete. If not, use a mop.
- Rinse with clean water
- Repeat if necessary
The reason for 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 one reason why just rinsing with warm water to remove salt is not effective.
For more stubborn salt stains, you can try using a commercial cleaner. Salt-Away is a cleaner that 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.
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It needs to be applied and the residue removed in the same manner as the vinegar solution. You can find it here at Amazon.
For the most stubborn salt stains, you may need to use a mild solution of hydrochloric (muriatic) acid. Mix 10 parts water to 1 part acid. This is actually a very mild concrete etch.
We only recommend this step if the salt deposits are heavy and all other methods discussed were not sufficient. We have instructions on how to mix and neutralize acid solutions here.
Important: Etching concrete opens the pores at the surface. This will allow for easier absorption of salts and deicing fluids. It’s imperative that the concrete be properly sealed, treated with a coating, or covered with a garage floor mat afterward.
This will prevent future contamination of salts and other deicing fluids that will stain and potentially damage the concrete.
Repair The Winter Damage To Your Garage Floor
Once the garage floor is clean and the salt residue removed, now is the time to repair any pitting or spalling that may have occurred. Polymer-modified cement patches and epoxy slurry repairs work extremely well for this.
They bond much better than regular cement and provide for a much stronger repair. Regular cement patches will not adhere well to concrete. They commonly delaminate, chip, and break away from the garage floor surface.
We have a detailed article where you can learn more about repairing spalling and pitting here.
Protect your garage floor from Salts and 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 and easiest method is to apply a quality sealer that blocks road salts and deicing fluids from penetrating into the concrete. We highly recommend a concrete densifier that has siliconate sealer added.
Our top recommendation is PS104 by Concrete Sealers USA.
The densifier helps to strengthen the surface of the concrete and the sealer provides high resistance to liquids and salt penetration.
It does not change the look of the concrete and will retain the same slip resistance as before treatment.
You can price PS104 here.
If you are undecided about using a simple sealer or applying a floor coating, we have an excellent article about garage floor sealers that discusses the differences.
If you want to prevent any fluids or road salts from coming in contact with the concrete of your garage, then we recommend the use of a winter containment mat.
These mats will keep the garage floor dry and collect all liquids, salt, snow, and other winter debris that drip off your vehicle.
Final Tips
Try to be diligent about cleaning the floor after the latest storm has passed. This helps to remove any corrosive fluids and minerals. The longer they sit on the concrete, the more potential damage they can do.
In addition, take the proper steps to prevent road salts and deicing fluids from damaging your concrete in the future.
For more information, you can read about recommended steps to winterize your garage floor here.
Restore your garage floor from winter damage and protect the concrete to prevent it from recurring in the future. Once you do, you will no longer have to fret over the anticipation of what damage spring reveals with your concrete floor.
Jim Taulbee says
What product can be used to remove the micro salts, I have heard that if not removed they will cause premature failure of Epoxy coatings, is this true?
Shea says
Hello Jim. If you are referring to removing the salts before application of epoxy, a proper acid etch that is neutralized and thoroughly rinsed removes the salts that can inhibit a good bond. Better yet, grinding does this as well as removing all laitance from the surface of the concrete which provides the best bond for epoxy.
If you are referring to after application, a quality epoxy coating is impervious to all salts. Depending on the coating, road salts may cause a slight discoloring if allowed to dry and set for a long period for the cheaper DIY kits. Mild soap and warm water do wonders for cleaning all residue from an epoxy floor. We also like to use a mild solution of Simple Green as well.
John Simpkins says
After I washed the epoxy garage floor, a section exposed to the sun when the garage door is open (to the south) lost it’s shiny surface. Not sure why, but I would like to restore that surface. What can I do?
Shea says
There isn’t a lot you can do to restore gloss John, other than applying a new coat. If you have a clear coat, then the process is fairly easy. It just requires roughing up the surface with 100 grit sandpaper and then apply a new clear coat. You are best off doing the entire floor instead of just one area however. The reason is that epoxy does not work like latex paint and blend right in. New areas are obvious and look much shinier than the surrounding areas. Plus, many times the roller edges show where the new coat meets the old.
Colleen says
Can I repaint a section if I am not satisfied, with the same epoxy paint , it has paintchips in it?
Shea says
It depends Colleen. Do you have a 1-part epoxy paint or an actual 2-part epoxy coating? Epoxy paint can be repainted over areas and it’s not very noticeable. However, with true 2-part epoxy coatings any recoated sections will stand out and look different.
Tom A. says
My concern is recurring white stains. My understanding is that road salt and the like, first penetrate into the concrete. Then, over time, that residue is slowly forced upward (time and again) and combined with C0-2 creates the white haze. Hence, you can clean all you want, but if there is still salt within the concrete, you essentially get nowhere. I am looking for a product or home remedy that does more than clean the top of the concrete but instead seeps into the concrete (as the salt has done), and neutralizes it so it doesn’t eventually rise to the surface and create the white powdery film/haze. Then I’ll clean the surface when I know the white stuff won’t return. Is my thinking correct on this, and what would you suggest?
Shea says
Hi Tom. If the concrete has been subjected to years of road salt, then yes, it can be very difficult to get all of it out of the concrete. It’s only forced up if the slab is below grade and you have moisture issues. However, if the slab gets wet from wet cars and such, the water that the concrete absorbs at the surface will work it’s way back to the top when the right atmospheric conditions exist. In either case, when the moisture gets to the top it will evaporate and deposit the salt crystals that it carried with it from within the concrete onto the surface. This is the white haze you refer to.
One of the keys that we mention in the article is to use a good shop vac to suck up the solution on the concrete. Keep adding solution so that the surface stays wet and then suck it up. This helps to draw the salt out. It can take many repeated applications to draw most of it out. Once you do, we highly recommend applying at the minimum a densifier with siliconate sealer added to help resist the salt intrusion to begin with. A coating would stop it all together.
Tom A. says
I suppose a little more info would have been good- I just put in a very nice (and expensive) concrete (brick sized) paver patio, 10′ x 10′. I was salting over a narrow pathway on that. I put first, regular road salt and then “Road Runner” which I thought was less caustic. Maybe 3 applications total. When I noticed I had a problem, I cleaned everything off with a wire brush, then bristle brush w/ soap & water, but then the haze returns over time (this is not a large polished concrete slab and there is pervious grout between the pavers). So yes, it gets wet routinely with the rain (no roof). I guess the removal of rinse water is important, so I’ll do that a few times and hope the re-emerging stains begin to stop reappearing. Thanks for reading.
Shea says
Ahh… that makes sense then. Yes, use a good wet shop vac to remove the neutralizing solution, rinse, and then vac again.
Theresa Stewar says
Good Afternoon, Thank you for the information. I had an epoxy floor with chips installed three years ago and the sealer has faded and is not stopping fluid from my auto to stain the floor. Can you provide the procedure/recommendations for recoating the protective coat? Thank you,
Shea says
Hi Theresa. It will require sanding of the floor to remove any ground in dirt, scratches, etc. Once you do that you can apply the new clear coating. We outline how it is done in this article here.
David Eggum says
What temperature should I wait to clean the winter salt off my garage floor?
Shea says
Hi David. Wait until it no longer reaches freezing overnight. If there is water within the concrete from the cleaning process that has not completely evaporated out, it can expand as it freezes and cause possible damage such as spalling.
Carol K Wonsowski says
A bag of salt was forgotten in our familyroom, now the carpet feels oily. Is there a way to fix/clean this? We already had it steam cleaned, byt it came back. Thank you
Shea says
Hello Carol. I’m sorry, but we are not specialists in carpet cleaning. Our only suggestion is to use a floor neutralizer first if it was exposed to salt before cleaning the carpet.