Concrete is one of the most common building materials used on floors, walls, driveways, patios, and other indoor and outdoor surfaces because of its low maintenance needs. However, removing paint from concrete surfaces can be overwhelming if you aren’t sure how to go about it.
Here’s what you can do to get paint off of concrete:
- Apply a paint stripper on the concrete surface
- Blast the painted area with sodium bicarbonate
- Use a concrete grinder
- Use a high-powered pressure machine
- Use white vinegar
Keep reading to get handy tips on removing paint from concrete, as well as answers to some frequently asked questions on paint removal.
1. Apply a Paint Stripper on the Concrete Surface
As the name suggests, the paint stripping method involves using chemical substances to strip off stubborn paint.
Today’s paint market is flooded with hundreds of paint strippers; some designed solely for oil or water-based paints while others work for both (like this Dumond Chemicals Advanced Paint Remover, available on Amazon). So be sure to get a stripper suited for the paint in question.
Most of these chemical strippers are environmentally friendly — they are low in odor, biodegradable, and free from caustic chemicals.
How to Do It
- Thoroughly clean the concrete surface and leave it to dry. Use a thick broom to sweep off any dirt and debris present on the surface. Then scrub the remaining stubborn dirt using a hard brush, mild soap, and water.
- Once clean, use a hosepipe or a pressure washing machine to wash off any grime or soap stud. Leave the surface to dry completely before applying the paint stripper.
- Now apply the paint stripper: Follow the manufacturer’s instructions and apply a generous amount of paint stripper on the concrete surface. Be sure to use protective gear to protect your skin from harsh chemicals in the stripper.
- Leave the stripper to perform its magic. Allow the stripper to sit for a few hours to weaken the paint. Be sure to keep children and animals away from the working area.
- Scrub the area. Once the paint stripper has settled for a few hours, it’s now time to scrub it off together with the loosened paint. Scrub the area until no more paint peels off.
- Wash off the area. Use a pressure washing machine or a garden hose pipe to clean the area. Pressurized water from the pressure machine or the hose pipe helps remove any stubborn paints on the surface.
- Assess the condition of the concrete surface. If you are not satisfied with the results, reapply the paint stripper, scrub and wash it off until you achieve the desired results.
Paint stripping is best suited for small paint areas on concrete from either oil or water-based paints.
When shopping for paint strippers, avoid any brand containing methylene chloride. Although strippers containing methylene chloride are fast and efficient, they are highly toxic when absorbed through the skin or inhaled. So, for the sake of your health and those around you, steer away from such paint strippers.
2. Blast the Painted Area With Sodium Bicarbonate
If the paint you’re dealing with is stubborn and hard to remove using chemical paint strippers, you can use soda blasting.
This method adopts the principle of mild abrasive blasting using sodium bicarbonate (baking soda) granules that are blasted against a concrete surface using high pressure.
Compared to traditional blasting methods, which mainly use sand as the blasting agent, soda blasting comes as a good alternative because it reduces damage to the concrete base underneath.
How to Do It
- Get a blasting unit: Here, you’ll need a pot blaster, which you can hire from a hardware or home improvement store near you. Most standard blasters can’t work with sodium bicarbonate particles, and you’ll need specialized blasting equipment.
- Obtain a good amount of sodium bicarbonate: The regular baking soda bought from the grocery stores isn’t ideal for soda blasting because it’s too fine to remove paint from concrete. Therefore, this process calls for special sodium bicarbonate particles that you can get from the hardware stores or buy online.
- Fill the blaster pot with sodium bicarbonate and follow the manufacturer’s instructions to ensure you set up everything accordingly.
- Now blast the painted area: Hold the blaster’s nozzle a foot and a half away from the concrete ground and start blasting. Remember to wear a mask or a respirator to avoid inhaling the blasted paint. Move the nozzle slowly and evenly over the painted area to ensure no paint remnants are left behind.
- Wash off the area: After blasting, wash the area thoroughly using a hose pipe or pressure washing machine to gauge the efficiency of the process.
Although it may sound like a simple task, it requires some skills and knowledge to operate the soda blaster effectively and safely. So if you feel that you don’t possess the necessary skills, it would be best to hire a professional.
Always wear a mask or a respirator to avoid inhaling the blasted pieces and tiny dust particles.
If you are blasting near indoor and outdoor plants and flowers, try reducing the spillage of the bicarbonate particles to the plant matter. This is because sodium bicarbonate’s high PH can cause browning and death of plants.
If you doubt your ability to perform this task effectively, consider hiring a professional blaster.
Soda blasting is effective in removing multiple layers of stubborn paint over a large area.
3. Use a Concrete Grinder
If you want to remove paint from a concrete surface without using chemicals, floor grinding is your best option. This method involves grinding off paint coatings using a concrete grinder.
How to Do It
Like with soda blasting, you need a special grinding machine for the operation. You can rent a handheld or walk-behind concrete grinder from a hardware or home improvement store or invest in one, depending on the frequency of use. A concrete grinder comes with the appropriate grinding disks.
With the machine in place, you’ll then need to run it slowly over the concrete surface to grind off the paint.
The weight of the grinder can make a great difference in the outcome, with heavier machines giving a more aggressive grinding. In addition, the weight of these machines allows the grinding discs to make better contact with the concrete surface for fine grinding.
Grinding produces fine dust particles that can be dangerous when inhaled. Therefore, as a precautionary measure, you should wear a respirator when performing this operation. For a dust-free experience, you can use a grinder equipped with a vacuum port to allow hooking up with an industrial port. A vacuum-equipped grinder also reduces messy clean-ups.
Additionally, unless you have skills in operating a concrete grinder, it’s best to hire a professional.
Floor grinding is effective in removing thin layers of paint.
4. Use a High-Power Pressure Washing Machine
Pressure washing or power washing involves using high-power pressure washing machines or hose pipes to remove thin layers of paint from concrete surfaces. This method is a chemical-free option that relies on the pressure of the water to work on concrete surfaces.
How to Do It
Get a power washing machine with a relatively high-pressure rating. You can buy one or rent from home improvement stores.
For best results, use a pressure machine with a flow rate of approximately 4 gallons per minute and a pressure rating of about 3000 psi (pounds per square inch).
You can also use a mild cleaning powder to increase efficiency.
Pressure washing effectively removes thin layers of paint that haven’t been left on the concrete surface for years.
Additional Tips for Removing Paint From Concrete
Spray Paint Removal
For seamless spray paint removal, you can use a mixture of water and trisodium phosphate (TSP). Trisodium phosphate is a chemical that weakens spray paints for ease of removal from concrete surfaces.
Just pour the mixture to the concrete surface, allow it to settle for some time, about 30 minutes or one hour, and then scrub it off using a hard brush.
Water-based paint is fairly easy to remove compared to other types of paint, such as oil-based variants. So vinegar should work in most cases.
You can also use a solution of methylated spirits, which act as dissolving solvents to dissolve the paint.
Once you pour the methylated spirits on the concrete surface, you should work on the surface as fast as possible because spirits dry up rapidly when poured on concrete.
If this approach doesn’t give the desired results, you can use paint strippers specially formulated for water-based paints.
Oil-based paint is rather difficult to remove, calling for a little more elbow grease. In such a case, you can use paint strippers and paint absorbents. Mix the two and apply them on the concrete surface and give them enough time to perform their magic, say one hour or so.
Then scrub them off using a hard brush and high-pressure water.
Why It’s So Hard to Get Paint Out of Concrete
Removing paint from concrete can be a painstaking process. Paint is known to stick on any surface it comes into contact with, and it can be a nuisance in extreme cases. Unfortunately, the case is not different when it comes to concrete surfaces.
Most concrete surfaces are highly porous and tend to absorb paint easily. When paint penetrates deeper into the concrete surfaces, it becomes hard to remove. However, with the right tools and approaches, the otherwise overwhelming process becomes easier.
Wrapping It Up
If you have been struggling with removing paint from concrete surfaces, I believe this step-by-step guide comes as an eye-opener to the various options you can use. First, however, you must be ready to put in a little time and effort to achieve the desired results.
Depending on your preference, you can use methods such as paint stripping, power washing, soda blasting, and floor grinding.