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Polyurethane versus Epoxy Coatings for Your Garage

polyurethane vs epoxy

The subject of a polyurethane or epoxy coating for a garage floor eventually comes up when deciding on what materials to use for your project.  Admittedly, it can become a bit confusing when asking around or researching which floor coating is best to use.

Epoxy and polyurethane are great for protecting your floor against stains, damage, chemicals, oils, and wear.  They are both light reflective, easy to clean, and long lasting.  They also have their own advantages depending on the application.  So which one should you use and what is the difference?  Well, the short answer for most applications is to use both.  Let’s see why.

Epoxy Floor Coating Benefits

Epoxy is a thermosetting polymer which is available in three different formulations for a garage floor coating and sealer; water based, solvent based, and 100% solids.  These formulations allow for varying degrees of thickness from 3 mils to over 10 mils for a single coating for a garage floor.  They also allow for ease of application, special bonding characteristics, and VOC considerations.  Epoxy bonds extremely well to properly prepared concrete and can sometimes be used as a resurfacing agent for old or worn concrete that needs a new garage floor surface.

The best epoxy formulations are 100% solids and provide for an extremely hard, thick, and impact resistant surface.  This self-leveling thickness contributes to filling in the small hairline cracks and imperfections of the floor as well as providing protection.  It also works well against hot tire pick up, scratching, and wear from abrasion.  Though some epoxy formulas come with U.V. inhibitors, they will still eventually yellow or amber as the industry calls it when exposed to sunlight for any length of time.  This is something to consider when choosing a garage floor finish.

Polyurethane Floor Coating Benefits

Like epoxy, polyurethane is a thermosetting polymer as well and is considered a high performance coating.  It is commonly known as urethane for short, though that it is technically incorrect and there is actually a big difference between polyurethane and urethane.  If someone is advertising a urethane coating, it is actually polyurethane.

polyurethane garage floor top coat

Polyurethane top coat

Of the different formulations available, aliphatic polyurethane is the desired choice for garage floors.  Though they are approximately 60% to 70% solids depending on the manufacturer, a polyurethane coating is only about 2 to 3 mils in thickness and can’t be adjusted as with epoxy.

Don’t let the thinner dry film thickness fool you however. Aliphatic polyurethane has more flexibility than epoxy and it is this flexibility that aids in absorbing impacts better.  It is also much more abrasion resistant.  In fact, some manufacturer’s claim that the wear resistance of polyurethane over epoxy is almost 3 to 1.  The resistance to chemicals is better than epoxy as well and this includes resistance to solvents such as methylene chloride which is the primary ingredient in paint stripper.

Another advantage of polyurethane over epoxy is that it is U.V. stable.  This means that it won’t yellow like epoxy does when exposed to small amounts of sunlight over a period of time.  The surface of polyurethane is not as hard as epoxy but it is much more scratch resistant, can tolerate larger temperature swings, and handles humidity much better.  It is also available in different finishes from satin to very glossy.

Though polyurethane has many advantages over epoxy, it does not bond well to concrete and its thin dry film thickness will not work well as a self-leveling coating to fill in small cracks and divots in the surface.  Another consideration is that most polyurethanes are solvent based, meaning they can have high VOC’s, and may require a respirator to apply.

Final Verdict

So, which should you use?  As a rule, it is believed that you will get maximum performance by using both polyurethane and epoxy together for your garage floor coating.  Whether you are applying the coating yourself or hiring a professional, epoxy is best used for building up the thickness of your floor coating then following up with polyurethane as a clear coat to protect it.  It will help protect the epoxy from yellowing and it will provide for a longer wearing and more scratch resistant surface.

If you don’t want to worry about yellowing at all, you can always use a colored polyurethane as a color coat before the clear coat.  Polyurethane is also a better medium than epoxy to mix in anti-slip aggregate if you truly want an anti-slip surface or want a solid colored floor without paint chips.

Something else to consider is that most epoxy clear coats are not actually crystal clear like polyurethane is.  Though they have no color, there is a slight yellowish brown tint to the clear in epoxy.  Unless you opt for a more satin finish, polyurethane can provide a very glossy surface that gives your floor depth.

So unless you are just doing a one-coat epoxy coating for your garage, a combination of epoxy and polyurethane is almost always the best answer to get the maximum combined benefit out of both materials.  The result is a high performance garage coating that will stand up to the rigors of a working garage for years to come.


  1. Thanx, Shea. I think I am going to go with Rustoleum Epoxy Clear after all, will turn off ignition sources and use respirator as suggested. And turn back ignition sources on after 24 hours, that should be long enough I think.

    Thanx for all your feedback and suggestion. It was really helpful in deciding this.

  2. I am unable to totally remove items from my garage, so I will apply coatings to one half of the floor at a time. My water heater and furnace are located in the garage, so it would be a problem to have them shut off for several days if I used solvent based coatings. Therefore, I believe I am limited to using water borne formulations unless you have some suggestions. I know that you recommend Drylok E1 as a 1 part water borne epoxy paint. I would like add chips and a top coat to add durability, add resistance to hot tire pickup and provide UV protection. What top coat would you recommend? How often would I have to refresh the top coat? You indicated that Drylok does not need a primer, but would durability be improved if I applied a primer?

    • Hi Richard. Drylok E1 is paint and not a 2 part resinous coating like epoxy. It is designed as a single product application, just like paint is, to provide for an inexpensive coating that is easy to apply and more durable than standard paint. It’s called a 1 part epoxy paint because it has a small amount of epoxy added to make it more durable than standard paint. Clear top coats are 2-part resinous coatings designed to chemically bond with similar coatings, not paint.

      For what you want to do, you need to step up to an actual water borne epoxy system. The Original Color Chips has a “Deluxe” kit that does what you are looking for. Primer, epoxy color base, color flakes, and a polyurethane top coat. The System 1 kit has a water borne polyurethane while the System 2 has a solvent based polyurethane. This is just one example of the many products available. Keep in mind that when working with solvent based coatings, ignition sources need to be shut off only while applying the coating if working in a well ventilated garage. They can be turned back on a few hours after.

      • Thanks for the information about The Original Color Chips products. However, I am confused about their Deluxe kit that uses a solvent based top coat over a water based epoxy. I read in a couple of places on the internet that a solvent based coating should not be applied over a water based coating because the solvents will disssolve the under coating. Can you please address that statement?

        • You most likely were reading about acrylic sealers Richard. They are different from 2-Part resinous coatings and should not be mixed. Polyurethanes, most of which are a solvent based coating, are compatible with most 2-Part resinous coating and are applied over water based epoxy primes and epoxy base coats on a regular basis.

  3. I am thinking of installing a floor coating on my 1000 sqft garage during the winter time here in Colorado. Which product would be able to handle the cold/warm temperature swings during the day the best? Which would be the best to install in the cold winter months?

    • Hi Scott. Either one can handle extreme temperature swings during the day. Once applied and cured, it’s not an issue. However, neither product is designed to be applied in cold weather. Epoxy and polyurethane systems generally cannot be applied to a substrate that is less than 50 degrees. Polyurea and polyapartic coatings can however. I suggest you read this article about applying epoxy in cold weather and this article about polyurea and polyaspartic coatings.

  4. Hi, Shea!

    I’m so glad I found your article! I was planing to paint/seal my basement bathroom tomorrow but it looks like I could use your advice! the paint stores I called were rather unhelpful =(

    The concrete floor was previously painted with latex floor paint about 20 years ago. I mopped it with soapy water, buffed it with a hand sander to rough up the old paint so it now has bare concrete patches scattered throughout. I then mopped it again with bleach water and towels.

    I want to it to look like ocean water, so was thinking of a teal paint covered with high gloss polyurethane clear coat I was going to add blue Mixol tint to. (I thought it would add depth?)

    but it sounds like polyurethane only sticks to epoxy and epoxy doesn’t stick to paint? I’d rather not sand any more than I already have.

    Could I paint the floor with tinted epoxy primer and cover that with polyurethane? Any other ideas?

    Thank You!!!

    • Hello Heidi, we are glad you found us! One thing we want to make clear is that a garage floor receives much more abuse than a bathroom floor and what you want to do is not something we would recommend for a garage. That said, you can apply a moisture cure polyurethane over latex paint. The key is to make sure the paint has fully dried before applying the polyurethane. Once it is dry, you will need to lightly scuff the surface with some 220 grit sandpaper and make sure it is clean and dry before application. Most moisture cure polyurethanes are water based and used for indoor flooring such as wood floors. They go on thin and need multiple coats applied.

      One idea that came up you might be interested in is a metallic epoxy finish. Pure Metallix is a division of The Original Color Chips and sells smaller sample cans of their product. They have a Dark Sea and Storm Cloud effect that looks a lot like an ocean. You can give them a call and see if their samples would be enough to accommodate you with your floor. Good luck!

  5. A year ago I had a new garage floor coated with pale grey with color chips. The floor would be beautiful except it is yellow in many places. In fact, it makes areas of chips underneath look tan. A company that did not do the floor told me it was because the sealer was put on too thick. I don’t really know what the problem is. Can I have the floor fixed/redone — what is required? Thanks

    • Hello Tom. You didn’t mention what type of coating was used. Assuming it was epoxy, it sounds like an epoxy clear was used as the final top coat. If the floor is exposed to sunlight the epoxy will eventually amber (yellow tint). How quickly it ambers depends on the quality of the epoxy and whether or not it had UV additives. Acrylics can yellow if put down too thick, but they are not used over epoxy.

      The top coat can be redone by sanding or grinding off the layer of clear and the re-coating with a polyurethane clear or even a polyaspartic clear. You will loose some of your chips in the process. If you do two coats however, you can broadcast color chips throughout the first coat of clear and then cover those with the second coat.

  6. Hi, I am doing my home new interiors. My daughter has moulded an epoxy tile which I wish to incorporate either in the flooring or on the wall. I am a little concerne about the durability of the tile though, hence need some suggestion. Can the tile be used in between other normal stone flooring tiles? Sorry if the question is too silly.

    • Hi Als, your question isn’t silly at all. If the tile is made of epoxy then yes, it can be used in the floor. Epoxy is harder than concrete when cured and will work fine in the floor.

  7. Thank you Shea.

  8. Hi Shea,
    I have a garage floor (1995) that I wish to cover with a metallic epoxy. Will I need to grind the top layer off first or can I get away with just using a stripper to remove oil spots and old sealer? After the epoxy is applied, I will use an aliphatic polyurethane with an anti-slip agent. Do you have a preferred/recommended polyurethane product?

    • Hello Brian. Yes, you definitely want to grind a floor that has any sealer on it. Using a stripper may remove most of the sealer but it will not prep the concrete properly for the epoxy. Most vendors that sell the metallic epoxy products also offer polyurethanes as well. We generally recommend that you stay with the vendor’s matched products. If they don’t offer one, we recommend using an aliphatic polyurethane coating. One thing to keep in mind about using an anti-slip agent with metallic epoxy floors is that the anti-slip agent will take some of the gloss and clarity out of the look of the metallic effects.

      Metallic epoxy floors are beautiful but they do depend on being applied properly. Make sure that the vendor you purchase from has good customer service to help you along. If you haven’t decided yet on who to purchase from yet, we recommend looking at both Legacy Industrial and Epoxy Master. They each have great product and good customer service.

  9. Hi Shea, I had an acid etched floor with 3 areas of different sealers . Waterbased sealer, solvent sealer , and epoxy. The epoxy surface scratches very easily, shallow, but unsightly , the water based sealer covering most of the areas has already had several problems with spills and destructive or impaired clean up; repaired now, but the polyurethane seems to be the safest bet for the future. Can it be applied over the water and solvent based sealers and on the epoxy will the surface scratches need repaired before top coating .

    • Hi Gary. Are the water and solvent based sealers acrylic products? If so, most polyurethane floor coating are not designed to be applied over them for a variety of reasons. You can verify this with the manufacturer for clarification. For epoxy, just rough up the surface with 150 grit sandpaper, sweep or vacuum, then wipe down with denatured alcohol. This will take down the scratches in the epoxy and provide enough bite for the polyurethane to adhere to. The scratches will disappear as well.

    • Gary. Shea is giving you good advice. If any of the products are acrylic I would remove them first. If it is epoxy do the sanding step and coat over it. Check us out at https://www.discountindustrialcoatings.com/. Lots of great products there.

  10. Hello, I read through most of the comments and didn’t see if you had answered previously. I am putting in a copper pennies floor in the bathroom it does not get any sunlight at all and I was wondering what to put down over the pennies? Something pourable or A Self-leveling two-part epoy and/or polyurethane. Or suggestion?
    Thank you

    • Hello Paul. For a penny floor you will want to put down 100% solids epoxy in order to fill the tall gaps between the pennies. The dry film thickness is the same as the wet film thickness so it will not leave large depressions like a water based epoxy would. Plus, it will give you a better coverage rate.

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