Blasting, grinding, scrapping, stripping – all these are techniques for removing old paint. The best method depends on how thick the paint coating is and how aggressive you want to be. In this post, we explain how to remove old paint from a concrete garage floor using different methods.
What You'll Learn Today
- What’s The Best Way To Remove Old Paint From a Concrete Garage Floor?
- How To Stay Safe When Removing Old Paint
- How To Use A Paint Stripper To Remove Old Paint From Concrete
- Using A Grinder To Remove Old Paint From Concrete
- How To Remove Paint From A Concrete Floor By Blasting
- Can A Pressure Washer or Power Washer Strip Paint From Concrete?
- How To Remove Paint Spots And Stains From a Concrete Garage Floor
What’s The Best Way To Remove Old Paint From a Concrete Garage Floor?
The best technique depends on the kind of paint you want to remove and how thick it is.
It also depends on where you want to do more than just remove paint. For example, if you also want to remove the sealer underneath the paint, you’ll need a more abrasive technique.
If you want to profile the concrete so that you can apply a new sealer, you’ll need to be even more aggressive.
Other factors to keep in mind when choosing the best way to remove old paint from concrete are safety, environment friendliness, and ease of use.
Here are the most common methods used to remove paint from concrete surfaces.
- Paint strippers – there are chemicals that can strip paint off concrete floors and walls. Because it’s a lot of work to apply the paint then scrape the loosened paint off, we recommend them for small floors and removing paint splatters and stains.
- Grinding – grinding is one of the best ways to remove old paint on a concrete garage floor. You can use an angle grinder, a floor grinder, or a rotary floor scrubber. The actual grinding media that’s attached to the tool can be a wheel or a buffer depending on how aggressive you want to be.
- Blasting – blasting is usually used in commercial settings but you can get a small blaster for home use. Types of blasters include soda, sand, and shot blasters. Blasters use media like sand or metal beads to repeatedly hit the surface of concrete and remove the top coating.
- Pressure and power washers – these are ideal if you want to avoid stirring up dust or using chemicals to remove paint.
How To Stay Safe When Removing Old Paint
Before we explain the different techniques in more detail, let’s talk safety.
Paint can contain hazardous chemicals, more so if it is old paint that was made with lead. Fumes and dust from the paint can be hazardous if they come into contact with your skin or you inhale them.
Here are the essential safety gear you need when removing old paint from concrete.
- Heavy duty gloves that protect both your hands and forearms. Gloves will protect you from the paint as well as the chemicals and tools you are working with.
- Respirator. You need a respirator that can protect you from concrete dust. This is a must-have if you are grinding or sanding the floor. Get a respirator with an N95 or P100 filter. It’ll protect you from silica-containing concrete dust and potential lead dust in paint.
- Eye protection to protect your eyes from small particles.
- Make sure you also put on protective shoes or boots as well as clothes that cover all your body.
- Ear protection when working with grinders and blasters.
How To Use A Paint Stripper To Remove Old Paint From Concrete
The first step is to buy a paint stripper that is suitable for concrete and the kind of paint on the floor.
Some strippers are formulated for oil-based paints while others work only with water-based paints. Others, like the Smart Strip Advanced Paint Remover work with all kinds of paints, varnishes, and acrylics.
Also check that the stripper can remove older lead-based paint.
Once you have the right stripper, here’s how to use it on the garage floor.
- Clear the garage then sweep and vacuum the floor to remove any dirt. Cover any surfaces and objects that can be damaged by chemicals or water such as the lower part of drywall.
- Apply a layer of paint stripper on the floor using a sprayer, brush, or whatever method is recommended on the label. Also check the recommended thickness.
- Leave the stripper to work on the paint for the specified amount of time. You can test the stripper on a small patch first to see how long it takes to strip off paint.
- Use a stiff nylon brush to scrape paint off the floor. Use a pressure washer to completely rinse the loose paint off the floor.
- Finish by cleaning the entire floor with a general purpose concrete floor cleaner to remove all traces of paint and chemicals. Rinse off the floor with a pressure washer.
Note: Avoid paint strippers and solvents containing methylene chloride (Dichloromethane). It’s effective but it is highly hazardous. The EPA banned its use in consumer paint removers.
Using A Grinder To Remove Old Paint From Concrete
If you already have an angle grinder at home, it’s a great tool for stripping paint off a concrete garage floor.
The only downside is that it’s small, so it’ll take longer to cover a large floor. We recommend it only for smaller floors or if you are stripping just a small section.
As for the wheel or disc, it depends on the thickness of the paint. If the paint layer is thick or you want to remove the paint along with the sealer, use an abrasive wheel such as a diamond or ceramic disc.
You can also get an angle grinder disc specifically for paint removal like this pack from QuickT.
For a thin paint layer, get a buffer disc. It’ll remove paint without damaging the floor underneath.
Tip: To reduce the amount of dust kicked up by the angle grinder, use a dust shroud such as the Diment grinding dust shroud. It connects to a vacuum and sucks up most of the concrete and paint dust.
For large garage floors, get a walk-behind floor grinder. Check if there’s one available for rent at the local Home Depot.
The other option is a buffer. A floor buffer works great for removing thin layers of paint. For best results, use a diamond buffer disc.
If you are dealing with an extra-thick layer of paint or you want to strip off concrete sealer, we’ve heard good things about Diamabrush.
It’s a wheel with exposed diamond blades that easily scrape off any coating be it paint or epoxy. Diamabrush can be used with a buffer or floor scrubber.
Here’s a video of a Diamabrush tool in action.
Tips For Using Floor Grinders To Remove Paint
- Do not apply too much pressure on the floor. It can damage the concrete floor. Just hold the grinder firmly and let it do its job.
- Keep moving. Spending too much time on one spot could eat into the concrete.
- Some grinders can only work on a wet surface to prevent overheating.
- Don’t forget to wear hand, eye, nose, and ear protection.
How To Remove Paint From A Concrete Floor By Blasting
When it comes to blasting, you have three options: shot blasting, sandblasting, and soda blasting.
Shot blasting is the most aggressive. It uses metal beads. Since it removes a lot of materials, it’s used only when you need to profile a concrete floor so that you can apply new sealer.
If you just want to remove paint, it’s overkill.
For most garage floors, sandblasting is the best option. It’s gentler on concrete and removes paint quickly. It also generates less dust than grinding.
Soda blasting using baking soda is an even gentler method that’s ideal for removing a thin layer of paint. It’s also suitable if you don’t want to damage the sealer underneath the paint.
You can buy small sandblasting and soda blasting machines for home use. You can also rent one at a local equipment store or rental.
Can A Pressure Washer or Power Washer Strip Paint From Concrete?
The final technique you can try for removing old paint from a concrete garage floor is a pressure washer or power washer.
A pressure washer directs cold water at a very high pressure. A powerful enough pressure washer (at least 3000 PSI) with a 15 degree nozzle can remove paint from a concrete surface. But it’s a bit slow and can struggle with thicker layers of paint.
The best way to use a pressure washer to remove paint is to first apply a paint remover on the floor. After it’s done it’s job, blast the floor with the pressure washer to remove the paint. It’ll come off much more easily.
If you don’t want to use any chemicals at all, buy or rent a power washer.
A power washer uses high pressure and very hot water to blast away at surfaces. This combo is highly effective at stripping paint off a concrete floor. And it’s fast.
Here’s a demonstration.
How To Remove Paint Spots And Stains From a Concrete Garage Floor
If you have paint splatter, marks or stains on the floor, the best option is a chemical paint remover.
Apply it just on the affected areas and let it sit for the recommended time. Then use a handheld scraper or a stiff bristled brush to clean away the paint.
Use a wet mop or sponge to completely clean up the spots.