Rust is a generally unpleasant fact of life and time.
Often if you park your car on your concrete driveway and it is uncovered, you will, over time, find some sort of rust stain on your driveway.
Being out in the elements, rain and melted snow will carry some of the rust from your car onto the concrete driveway.
Don’t worry if you find yourself in this predicament.
We have been where you are and have done some research to figure out the best way to use a pressure washer and remove rust stains from your concrete.
Continue reading below to learn how to remove rust stains from concrete with a pressure washer.
What You’ll Need
- Pressure washer cleaner (available here)
- Pressure washer
Continue reading below for step-by-step instructions on how to remove rust from concrete with a pressure washer.
1. Wet Driveway And Surrounding Vegetation
Take the nearest hose and wet the entire driveway area with the rust spots and the driveway area surrounding it.
You will also want to soak the vegetation where the water and cleaner will eventually run off when you use the pressure washer later.
It is essential to make sure that the surrounding vegetation is saturated and the soil.
This way, it will not allow the plants to absorb any of the chemicals in the pressure washer cleaner and the residue from the rust.
2. Apply Cleaner To Rust Stain
Ensure that your pressure washer has the concrete pressure washer cleaner in the cleaning solution compartment.
Starting in sections, apply the concrete cleaner with the pressure washer to the rust spot on the concrete driveway.
Thoroughly soak the rust spot as concrete is very porous, and you want to ensure that the concrete pressure washer cleaner reaches the lower layers of rust.
Be sure to start in the downhill sections first so that when you wash off the dirt and cleaner, they do not run over clean areas and make them dirty again.
Also, ensure that the size of the spots you are working on is not too large.
You do not want the cleaner and the driveway surface to dry out.
Allow the concrete pressure washer cleaner to sit on the rust stain for about 10 minutes.
3. Pressure Wash Driveway
Using your pressure washer without the cleaning solution, pressure wash the entire driveway.
Start at the highest point and work downhill in sections.
If needed, spend longer on the sections that have the rust stain to ensure you are getting out the stain.
You may also find that the stain is still faintly there.
You can repeat the steps above until you have completely removed the stain.
Remember that concrete is porous, and the rust stain may have seeped down into the lower levels.
These layers may require more than one concrete pressure washer cleaner treatment.
Will CLR Remove Rust From Concrete?
For some, CLR is a safer choice. You can use CLR to remove rust from your concrete driveway effectively.
Its ingredients include lactic acid and gluconic acid, which will remove the rust stain, but it does not contain harsh chemicals like phosphates.
Remember, though, that CLR should not be used on painted, sealed, coated, or newer concrete because its acidic characteristics will cause the color and texture of the concrete to be changed.
Will Bleach Remove Rust From Concrete?
It is not recommended to use bleach to remove rust from concrete.
While bleach is often used as a go-to stain remover, it will not be effective enough on concrete.
Concrete is very porous, and bleach does not penetrate below its surface.
The rust stains will still be deeper in the concrete than the bleach can reach.
The bleach will remove the surface rust stains, but the rust stains in the lower layers will still be visible.
Will Baking Soda Remove Rust From Concrete?
If you do not want to use harsh chemicals to remove rust stains or even do not want to have to purchase a cleaning solution, baking soda may be a good idea for your use.
You can use several additional items with baking soda to make it more effective.
Baking soda has abrasive qualities that make it easier to remove stains.
Adding hydrogen peroxide will break down and remove rust stains on the concrete driveway.
If you add baking soda with liquid dish soap, you can create a paste that will be a very effective way to remove the rust stain.
You will apply the baking soda paste created with hydrogen peroxide or liquid dish soap onto the rust stain for both methods.
With the liquid dish soap mixture, you can also add some hot water to the paste.
Allow the paste to sit on the rust stain from 10 minutes to half an hour.
Then you can carefully scrub the area with a wire bristle brush.
Depending on the level of finished concrete, you may want to skip this step or be very gentle with the scrubbing.
Then rinse off the area with water.
Will Muriatic Acid Remove Rust From Concrete?
Some people choose to use muriatic acid to remove rust from concrete, but there are mixed opinions on whether or not you should.
People who do use it recommend that you dilute the muriatic acid.
You can mix muriatic acid and water to create a 1:1 ratio of solution.
You can also decrease the amount of muriatic acid, but you should not have more muriatic acid than water in your solution.
Then you can spray this diluted solution onto the rust stain.
Then after letting the solution sit for at most 10 minutes, scrub the stain with a stiff brush.
Finally, rinse the solution with either a power washer or a hose.
On the other hand, some people do not recommend you use muriatic acid.
Muriatic acid is a powerful corrosive acid that may eat away at your concrete.