You don’t have to put up with an old drip
In the process of repainting your gutters, you let a little color get where it shouldn’t—on your concrete floor. Never fear—there’s no need to live with a blue-speckled patio as there are several methods for removing paint from concrete.
Read on to learn five proven methods for cleaning unruly paint drips from your concrete.
Why Do I Need to Remove Paint from Concrete?
It’s possible that the paint was—once, at least—intentional, an attempt to spruce up the typical drab gray of concrete with a splash of color. Other times, it might be the result of an accident or random vandalism. Whether the goal is to restore the concrete to its original color or get rid of random splotches, proper paint removal is important as concrete is a porous surface; paint can seep into concrete much deeper than other materials.
If you simply wish to repaint the concrete, you don’t need to remove it fully, provided you are using the same kind of paint (oil-based or water-based) or plan to use a primer. Simply scrape away the peeling or flaking paint, sand the area, and then clean away any flakes with a vacuum. After these quick steps, you can repaint the concrete.
How to Prep to Get Paint Off Concrete
Before you begin, make sure the area is completely clean and dry. Start by scraping away any peeling or flaking paint and vacuuming those bits up.
Next, thoroughly clean the surface. A good scrubbing with soap and water is a fine option, but you can also use TSP—diluted trisodium phosphate. Warning: TSP is extremely potent and should be handled with care and precaution. You should wear gloves and goggles when handling TSP or paint strippers and make sure the chemicals are nowhere near beloved plants, animals, or children. If any plants sit near the concrete, you should cover them with plastic sheeting taped down to the ground.
The area will need to dry for at least three hours before proceeding.
5 Ways to Remove Paint from Concrete Flooring
Depending on your comfort with power tools, you can choose to remove paint from your concrete flooring with chemicals or pay a visit to your local hardware store to rent the types of machines the pros use.
1. Use Paint Strippers
The same commercially available paint strippers that were originally designed to remove paint from wood also work with concrete. When shopping for a paint stripping product, ensure it is formulated for the type of paint that needs removal. Some formulations only work with water-based latex paint, while others excel with oil-based paints. If you are unsure as to what kind of paint was used, using a stripper intended for oil-based paints is your best bet.
Additionally, err on the side of caution and go for an environmentally friendly paint stripper that is safe for both indoor and outdoor use. Avoid paint strippers containing methylene chloride, if possible. If you end up with a product containing methylene chloride, wear protective eyewear, a mask, and gloves.
Here are the basic steps to removing paint from concrete using a commercially available paint stripper.
Cover nearby plants with plastic sheeting; you should tape the plastic to the ground so it doesn’t move around as you work.
Apply a thick layer of the paint stripper using a brush, broom, squeegee, or another approved tool. Check the instructions for more options.
Let the paint stripper sit until it fully penetrates the concrete, which causes the paint to soften. This takes four to 24 hours.
Remove the paint with a scraper or wire brush.
Is the paint still hanging on for dear life? Repeat steps one through three.
If you wish to repaint the concrete at another time, apply a limestone wash solution to the concrete. Follow the instructions on the solution’s bottle, but be sure to rinse it after the recommended amount of time.
Clean up any lingering residue with a mop and clean the concrete with a degreaser.
2. Use a Power Washer
Believe it or not, a standard power washer is highly effective at removing paint from concrete. If you don’t already have one on hand, you can rent a power washer or contact a local pressure washing company and have them clear your concrete.
Here are the basic steps on using a power washer to remove paint from concrete. Also, just to be clear, this is for outdoor use only.
Use a power washer with a pressure rating of at least 3000 psi and a flow rate of at least four gallons per minute. Anything lower cleans the concrete … but keeps the paint. Also, use a 15- to 25-degree nozzle for best results.
Hook the washer up according to the manufacturer’s instructions and position yourself in front of the impacted concrete.
Hold the wand at a downward angle and stay at least one foot away from the concrete.
Power on the washer and move it in a sweeping motion until the paint clears away.
Some other pressure washing tips include patching up any broken bricks and keeping an eye on your home’s water supply.
3. Soda Blasting
Soda blasting does not involve pouring a can of pop over your concrete, but it does involve slamming it hard with sodium bicarbonate.
Just like with power washing, you need specialized equipment, in this case, an industrial soda blaster. These machines cost anywhere from $100 to $1,500, depending on the features, though they are also available for rent from hardware stores. You’ll also need specialized sodium bicarbonate to do the job, which is also available from hardware stores.
Here are the steps to remove paint from concrete using a soda blaster. And, just as with power washing, this is for outdoor use only.
Wear a heavy-duty respiration mask so you don’t breathe in the sodium bicarbonate fumes.
Remove any plants from the treatment area, as the high pH levels of sodium bicarbonate wreak havoc on flora.
Setup the blaster according to the manufacturer’s instructions. These machines are tricky to operate, so don’t hesitate to contact an expert for help.
Spray the sodium mixture from a safe distance to manually regulate the pressure and protect the integrity of the concrete.
Don’t overdo it. Once the paint begins peeling off the concrete, finish the job with a brush.
There is yet another powerful machine that removes paint from concrete: the humble sandblaster. Again, you’ll need the appropriate hardware. Industrial sandblasters cost, on average, around $1,000, but your local hardware store should have them available for rent, along with the crystalline silica solution needed for operation.
Crystalline silica is highly toxic when inhaled and damages skin, so wear a respirator mask, safety glasses, gloves, earmuffs, and long sleeves.
Before starting, familiarize yourself with the instructions and watch some tutorial videos. Sandblasters pump out large amounts of crystalline silica at once, which damages concrete if misused.
Turn on the sandblaster and open up the nozzle valve slowly to initiate a fine mist of sand, regulating as necessary.
Move the nozzle in slow, smooth lines. Start with moving up and down and then across the impacted area. Avoid repeatedly spraying the same spots to preserve the concrete.
Work slowly and methodically until the paint is gone.
5. Try a DIY Mixture
Looking to minimize chemical use and don’t feel like learning how to operate industrial machinery? Try a DIY paint-stripping formulation.
There are several well-regarded formulations, but they typically have a few ingredients in common, such as highly absorbent materials like clay and cat litter. Here is a simple recipe and instructions for use.
Combine one cup of finely ground clay, one cup of cat litter, and a splash (around one-half cup) of commercial paint thinner, though vinegar works in a pinch.
Don rubber gloves for protection and combine the ingredients until a thick paste forms.
Apply the paste in a heavy layer to the impacted concrete.
Let it soak for two hours or longer.
Remover the loosened paint with a wire scrub brush or paint scraper.
How to Prevent Paint From Staining Concrete
In the future, protect your concrete before working with paint, as concrete essentially acts like a big, hard sponge. Start by applying a sealant or floor wax to the concrete, which acts as a barrier between the concrete and the paint, should accidents happen. Also, speed is key here. If paint spills on concrete, remove it with water and detergent soap before it dries.
There are two standard sealers to choose from: penetrating concrete sealers or durable concrete coatings. Opt for durable concrete coatings which thoroughly coat the concrete to prevent the penetration of fluids.
DIY vs Hiring a Pro to Remove Paint from Concrete
Of course, if you really want the job done right, contact a local paint stripping company. These professionals have more than their fair share of paint-laden concrete, and they’ll have just the right tools for the job. Pros are well-versed with sandblasters, soda blasters, pressure washers, and even commercial paint strippers.
This is a great idea if large areas of concrete are absolutely overrun with paint, but is considered a bit of overkill when dealing with just a few paint spots. Professional paint strippers charge anywhere from $30 to $50 per hour and may necessitate a two-hour minimum to begin work.
Frequently Asked Questions
Yes, but with caution. A floor grinder is intended to level and polish concrete, so it is a very powerful tool. To remove paint, the floor grinder should be set to 35 square feet per minute or less to minimize the pressure, without the use of pocket weights. You might need to go over the surface two times to get any paint that has sunk into the concrete’s pores.
Concrete is extremely porous. Without a proper sealing, it will absorb just about anything it comes in contact with, including water and ice. During the colder months with freeze-thaw cycles, this could cause the concrete to crack and become damaged in other ways.