Can You Use Polyurethane Paint On Concrete?

Polyurethane sealers are thicker than acrylic sealers. They help protect against chemicals and abrasion. So, can polyurethane paint be used on concrete?

Polyurethanes can be used for both interior and exterior concrete surfaces to provide a high-quality, durable finish that is transparent and does not turn yellow over time.

Polyurethane is a clear sealant that can be used on concrete to protect it and make it last longer. It is often used in the construction industry as a protective coating for concrete surfaces, outdoor furniture, patios, etc. 

This article will explore more about polyurethane and provide information about how to use polyurethane correctly on concrete surfaces so you don’t damage your property with improper application of the product.

Can You Use Oil-based Polyurethane On Concrete?

Yes, you can. The primary advantage of using oil-based polyurethane on concrete is that it creates a very tough paint surface. The outstanding adhesion makes it an ideal choice for floors, patios, etc. Always use adequate ventilation (such as a fan) when applying and wait for the paint to dry completely before sealing it.

Oil-based coatings for concrete floors such as polyurethane can be applied using a roller or a sprayer. While applying the layer, care must be taken to avoid its splatter on other surfaces that could get stained by wet paint. Also, while painting, an extra cloth should be laid on the ground beneath the surface to avoid paint stains.

Applying a new coating over an old one is more straightforward than spreading it on a bare concrete floor. The previous coat may have become uneven with time, and the application of additional coats could cause some amount of unevenness. Therefore, when applying polyurethane, avoid going over the same area more than once, as this will cause unnecessary build-up. 

Before applying a new coat, ensure that the previous one has dried well and is entirely free of dust and debris. All cracks and crevices should be filled using cement or some other filler material prior to applying polyurethane. 

Related Read: How To Paint Over Concrete Sealer?

How To Apply Polyurethane On Concrete?

Here are a few steps that will teach you how to apply polyurethane on concrete.

Concrete decks are becoming more popular in public buildings and apartment construction nowadays. So, to protect the appearance of your concrete, mainly if it’s etched, stamped, or stained, you’ll need to use a sealing agent. 

Polyurethane is one of the cost-effective and most efficient options to seal your deck. Once applied, preservation is easy, also applying a new layer when required will treat maximum problems.

Below are some steps that might be helpful for you to apply polyurethane on concrete appropriately.

1. Cleanse Away Oil Spills and Other Dusty Areas

Pour odorless mineral spirits on oil spills and scrub them down with a cleaning brush. Take paper towels to mop the excess cleaner and grease. Alternately, try cleaning it using trisodium phosphate or any pre-paint cleaner to wash the grease spills with a dusting brush. 

  • If you don’t clean the dirt and grease up, the sealant will never stick properly
  • Now, simply pour the cleaner on the grease stain until you cover it all. Then wait for it to dry before sweeping up any extra powder that may have been created while cleaning the floor.
  • Ensure to clean up any soap and grease residue with dry towels. 

2. Take a Concrete Cleaner to Prepare the Cement for the Sealer

You’ll need to get a good scrubbing broom and some phosphoric acid or another type of concrete cleaner. Now, spritz or pour the concrete cleaner onto the floor, then take the scrubbing broom with a long handle to clean the floor.

To ensure that the area is spotless, work in batches across the room. You can even buy a kit to resurface your floors, and it often comes with an all-purpose concrete cleaner.

3. Wash the Cleaner Off

You’ll need a hose and some water. Work your way across the surface from top-down, or start at one end of the room or hallway if you want to make things easier for yourself. If it’s inside-out, work towards an exit door.

In addition, some people like to use a power washer for this procedure. To speed up the drying method, you can squeeze the water off the deck. However, you still need to wait for 24 hours to let the floor dry.

4. Apply Concrete Restoration Caulk on Cracks

If you have cracked floors, now is an excellent time to fill them in. Squeeze the caulk into your crack and make sure it’s filled up as much as possible; use enough so that there are no gaps between cracks. Smooth out any bumps left behind with a trowel before letting it dry for an appropriate amount of time.

5. Use the Polyurethane Sealer

Mix the polyurethane carefully with a wooden paint paddle until it becomes clear to the base of the can. Don’t sway this around, or you will get bubbles in it, and they might mess up the looks of the final product. Also, don’t forget to put the shoe covers over top of the shoes to avoid dirty the floor during this process. 

Related Read: How To Apply Polyurethane Over Old Polyurethane?

6. Divide the room space for a smooth finish

Splash a tiny amount of polyurethane onto the floor, beginning in one corner. Slowly work towards an exit so that you don’t paint yourself into a corner. Apply it slowly and smoothly with a lamb’s wool applicator to avoid agitation while overlapping your strokes for complete coverage and keeping the wet edge intact. 

7. Take a Hand Brush to Apply the Sealer

Now, choose a 2-3 inches broad paintbrush and begin applying the sealer or paint. Soak the paintbrush into the binder. Apply a nice, even coat of sealer to the edges where your brush or pad may not be able to. Take care with each stroke in order to avoid any spillage. 

8. Paint the Sealer on Concrete With a Rolling Brush or Paint Pad

Make sure to keep rolling the roller or brush across the floor, sliding it along, and adding more sealer as needed. If you’re using a paint pad, make sure that you have enough on your tool so that when you start painting with it again after dipping in the sealant for another coat, there isn’t any residue left behind.

If you’re painting a large surface, it’s best to start with an extensive wet edge. If the paint dries before blending into your next stroke, use any roller or pad designed for quick and easy coverage of broad areas.

Related Read: Does Polyurethane Stick To Plastic?

9. If Required, Add a Second Coat

Few sealers might need a second coat. For instance, exposes or acrylics won’t be durable without a double layer of protection. Also, adding an extra layer will further ensure you have uniform coverage on your surface.

Wait until the first coat dries completely before adding the next one to ensure that everything looks perfect. Read the manufacturer’s directions carefully; some binders might need as long as 5-7 days to dry before you add a second coat.

Related Read: Can You Use Wood Paint on Metal?

Can Varathane Polyurethane Be Used On Concrete?

No, this kind of polyurethane is not compatible with concrete, for that matter. If it’s applied during the recoat, you’ll end up with a yellow-tinted mess. You need to scour off from the surface to not contaminate the other coats on top of the paint job. 

You cannot apply varathane over concrete because water-based finishes will not adhere well to self-leveling materials such as Concrete Sealer.

You must use a solvent-based polyurethane varnish if you are going to apply it over the sealer. These products take 6-8 hours or longer to dry than water-based finishes, so cracks and bubbles will be much less frequent when using them.

If you are looking for a maximum gloss, then use varathane over concrete sealed with concrete sealer. Polyurethane varnish will be the most durable and require little or no maintenance but is not as glossy as a polyurethane spray.

This sealer self-levels and penetrates the surface of the concrete. Once you apply this material, you will never have any problems with dust or other airborne contamination sticking to the floor. It will not decrease your ability to mop and sweep debris from the floor like you would with a polyurethane finish.

Related Read: Can You Apply Polyurethane With a Rag?

How Long Does Polyurethane Last On Concrete?

It depends on the type of polyurethane. If you use a water-born polyurethane finish, like Varathane, then it should last ten years or more. However, if you use a solvent-based polyurethane varnish standard in stores, the finish will last a lot less time. 

In addition, it also depends upon factors such as whether the surface is regularly exposed to rain or sunlight. If you live in an area of high humidity or lots of dust, then the finish will last about five years.

If you keep it clean and vacuumed, it should last about ten without being retouched. The most important is that they contain additives that will resist cracking and peeling much better than any other finish.

But one must also keep in mind that a good polyurethane finish takes three to four times longer to dry than a comparable water-based floor finish. Something like 30 hours for the solvent-based polyurethanes and 8-12 hours for the Water-based polyurethanes.

Related Read: How To Apply Polyurethane on Metal?

Final Words

Polyurethane is an excellent choice because it’s flexible and can be used on many different types of surfaces, including concrete. If you’ve been looking for new ways to protect or enhance the look of your property, polyurethane could be a great option.

When using polyurethane for your painting project, make sure you have cleaned the surface thoroughly and allowed it to dry before applying the protective topcoat, as mentioned in the steps above. We hope that this article is profitable for you in understanding how to use polyurethane in the best way. 

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