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 garage 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 coating that also acts as a concrete sealer. It is available in three different formulations; 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. They can also dictate the ease of application, provide special bonding characteristics, and offer different VOC considerations.
Epoxy bonds extremely well to properly prepared concrete. It is sometimes used as a resurfacing agent for old or worn concrete and as a repair material for concrete cracks, pitting, and other surface repairs.
The best epoxy formulations are high solids to 100% solids. They are an extremely hard, thick, and impact resistant surface. This self-leveling thickness contributes to filling in the small hairline cracks and imperfections of the surface as well as providing a high build coating for protection.
They also work well against hot tire pick up 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 an epoxy garage floor coating.
Polyurethane Floor Coating Benefits
Like epoxy, polyurethane is a thermosetting polymer and considered a high performance coating. It is commonly known as urethane for short, though that it is technically incorrect. There is actually a big difference between polyurethane and urethane. If someone is advertising a urethane coating, it is actually polyurethane.
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. It can’t be applied any thicker in one application as some epoxy coatings can.
Don’t let the thinner dry film thickness fool you, however. Aliphatic polyurethane has more flexibility than epoxy which makes the surface much more scratch resistant. It also aids in absorbing impacts better and provides much higher abrasion resistance. In fact, some manufacturer’s claim that the wear resistance of polyurethane over epoxy is almost 3 to 1.
Polyurethane also has a higher resistance to chemicals than epoxy. This includes resistance to petroleum products and 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. It can also tolerate larger temperature swings and handles humidity much better.
Polyurethane concrete coatings have a very glossy finish, though some brands have the option of a satin finish. It is also a better medium than epoxy to mix in anti-slip aggregate if you want an anti-slip surface.
Despite the fact that polyurethane has many advantages over epoxy, it does not bond well to concrete. Its thin dry film thickness means that it is not a high build coating either. It will not work well to fill in small cracks and divots in the surface. Another consideration is that most polyurethanes are solvent based, meaning some can have high VOC’s and may not be shipped to your state or to particular counties.
Final Verdict
So, which should you use? As a rule, 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 and providing color. You would then follow up with polyurethane as a clear coat to protect it. The clear coat will provide for a longer wearing and more scratch resistant surface.
If you don’t want to worry about yellowing at all, one option is to apply a full color flake floor. The acrylic color chips are U.V. stable and will not yellow. Follow up with a couple coats of clear polyurethane over the chips and yellowing will never be a problem.
Another option is to apply a colored polyurethane over an epoxy primer. You can then apply a clear polyurethane over that. This is an excellent choice for those that want a floor without color chips.
Something else to consider is that most epoxy clear coats are not actually crystal clear. Though they may be clear in color, there is still a slight tint to the coating. Polyurethane on the other hand is considered water clear. It can provide a very clear and 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.
You said that polyurethane is U.V. resistant, but will the epoxy under it yellow? I don’t want to spend the extra money urethane if it does.
That’s a great question Fordman and thanks for stopping by. The polyurethane top coat will filter out the U.V. rays and protect the epoxy underneath from turning yellow. Think of it as a sunscreen for epoxy.
Great Post. This is exactly what I was looking for. I am getting ready to paint my garage floor with 2-part epoxy paint (solid-based). After researching, I realized this epoxy will discolor from UV rays and I plan on leaving my garage door open for several hours a day in Florida. (I have my reasons.)
Could you please give some suggestions for some aliphatic polyurethane products. I’m having a hard time finding a product that I’m sure is aliphatic and that will work well with the Rust-oleum Professional Epoxy Garage Floor coating. Any suggestions would be greatly appreciated!
Thanks!
Thanks for the kudos Jay. As far as finding aliphatic polyurethane floor coatings, it’s not as hard as you think. Remember if you are doing a search that many companies refer to them as ” urethanes”. When looking, be sure to check the TDS sheets. Legacy Industrial has one here and Concrete Solutions offers both a water based polyurethane and solvent based polyurethane.
Most companies are more than happy to talk to you about the compatibility issues of using their brand in conjunction with another. It’s the smart thing to do. Good luck with your project!
I am checking to see if I can use clear epoxy over a concrete floor dye? Or will the dye not allow the epoxy to affix itself properly to the concrete for good adhesion?
Hi Jimmy and thanks for visiting us. Yes, you can epoxy over a concrete dye or stain. Dyes penetrate the concrete to leave a colored residue without forming a film and stains react with the free lime to create color. Just make sure that the concrete surface has been prepared properly to accept the epoxy. Also, it’s always wise to check with the manufacturer of the color dye to make sure it doesn’t react with the epoxy.
Can I epoxy over VCT tile that has been stripped of wax/sealer and hand sanded with 80 grit sandpaper? Will the epoxy bond to this substrate? My plan is to epoxy over the VCT tile and then apply a coat of aliphatic urethane. Assuming this is ok to do, how long should I allow the epoxy to dry before applying the urethane?
Hello Jody and thanks for the great questions. Yes, you can epoxy over vinyl composite tile with the prep methods that you just described and be sure you wipe it down with denatured alcohol as your final step. You should use a 100% solids epoxy because it will provide for a thick coat and self level over any small gaps between the tiles. Unless using an accelerator, wait a minimum of 10 – 12 hours before applying the urethane. The epoxy should not be tacky to the touch. Don’t wait longer than 24 hours or you will have to prep the surface of the epoxy.
I have 2 different paint specialists from Glidden and Devoe telling me that any 2 part epoxy or 2 part urethane is not safe for VCT tile because of the chemical reaction. They say the chemical reaction could melt the VCT tile and adhesive. They also say that neither will bond properly to the tile. Is this true? I only want to do this one time and I want to do it right.
Thank you.
Great article. Clear and helpful. to the question of who makes aliphatic urethane, one company with which I have had commercial success is TNEMEC – spell it backwards and it spells cement. They are a leader in above ground water tank coatings but I don’t know if their product is available retail.
Great Article..
But I want to ask about a floor of workshops; mechanical, electrical and projects workshops. Is the epoxy better or the polyurethane? Knowing that the floor of the workshops is at the same time the surface roof of water tank..
I am tending to the side of the Polyurethane but still want to hear your opinion.
Yes Rafael, a polyurethane coating in most cases is going to be the better choice of the two when used in a work environment. It will provide for better scratch resistance, wear, impact resistance, and better resistance to chemicals of all types.
Thank you Shea for your reply, yes as many told me..Polyurethane is much better than Epoxy in my case/conditions.
Can I ask you also about the “Polished Concrete” !? Could it be used or still the polyurethane the best choice !?
Thank you in advance and waiting for your reply..
You can do a semi-polished concrete surface with a special sealer. It would be similar to the concrete floors that you see in some warehouses and big home improvement centers. Unlike a polyurethane coating, they do require work to stay maintained and will not be as resistant to some chemicals.
I just used 100% solid epoxy w/ flecks (from JAM flooring) on my garage floor. I didn’t realize it was going to be slippery when it gets wet, which… it will. I live in NE PA w/ long winters. What can I use to make it non slip & where would I get it from?
Hello Anna and congratulations on your new floor! In order to create a non-slip surface, a non-slip additive such as Shark Grip should have been added to the mix when you installed it. What you can do however is apply a top coat of clear epoxy or polyurethane to your Jam flooring base coat with a non-slip additive added to that. You will need to lightly sand or roughen up the surface of your new epoxy before applying a top coat. Polyurethane has a higher spread rate than epoxy and makes for a good medium for a non-slip additive. You might want to call one of our sponsors such as Legacy Industrial. They have these type of products and can give you and estimate for materials.
If using epoxy over VCT flooring does it need to be primed before the epoxy is applied? And do you need to prep the epoxy for polyurethane
Hello Heidi and thanks for the good questions. In most cases a primer is not necessary if you want to epoxy over VCT flooring. Make sure the tiles are clean first (no wax either) and then you need to rough them up for the epoxy to adhere properly. If the tile isn’t down yet it’s generally a good idea to rough them up first. The reason for this is that opposite colors can bleed together if not done carefully (black and white tile for example).
100% solids epoxy is recommended and contact the manufacturer first to determine if there are any compatibility issues. Squeegee the first coat on real thin to just fill any gaps in the tile. This will help to prevent out gassing and is also referred to as the grout coat. Then apply a full coat as normal followed by the polyurethane. The poly just goes on within 24 hours of the epoxy, no prep needed. Just follow the manufacturer’s directions.
I painted my old tile kitchen counter with two coats of Homex epoxy paint. It seems to still be a bit soft in some spots and I painted it about 2 weeks ago. I want to strengthen the paint with a few coats oil based clear polyurethane. Do I need to sand it first? I reviewed your previous comment/responses and it seems as though it will help protect it. Your thoughts? I am going to paint my tiled bathroom floor as well…
Hello Amber. Almost anytime you apply an epoxy or polyurethane to a finish that has cured for more than a day, you will need to roughen up the surface by sanding or using an aggressive scrubbing pad. Always follow the manufacturer’s recommendations for preparation. My concern however would be the soft spots that you still have after two weeks. You don’t want to apply anything over it until it is cured properly.
Kind of an odd question but I’m redoing my bathroom floor with pennies and I’m looking for a topcoat to protect the floor. I found your post very helpful but I was wondering if anything that is sold at a big box store like Lowe’s would be an aliphatic polyurethane floor coating or can I even use it over the cooper flooring. I want to be very careful with my choice since there is a window and it does get direct sunlight, I don’t want it to yellow on me. Also, would obscured glass filter out the U.V. Rays?
Wow, a penny floor sounds cool! Polyurethane wouldn’t be a good initial coating because it’s too thin to coat the pennies with. Epoxy is a much better choice because it can be applied in much thicker coats, but it will yellow in direct sunlight. Glass will slow the process down but it will still eventually yellow. A final coat of polyurethane would slow the process down even more but you would eventually end up with the amber appearance. I think your best bet would be to coat the pennies with polyurea. Polyurea cures crystal clear and U.V. light will not make it yellow.
Anti Slip Floor Coating provides better protection from abrasion and chemicals and it comes in a variety of color options.
I want to use a solid epoxy on my garage floor but I am wondering who is recommended in my area of Overland Park, Kansas. Any ideas and price ranges for this type of floor per square foot?
Hello William. Pricing can vary depending on region. It can be anywhere from $3.50 – $5.50 a square foot depending on the amount of coats plus other factors. I would contact Gene Dean from Elite Crete Indiana. They are a decorative concrete and epoxy floor coatings supplier that also trains installers. He is the Director of Training and Tech Support for the company and is in contact with many installers through out the mid west that he may be able to recommend for you. Just call the number on the site or you can email him at info@elitecreteindiana.com
Hi Shea,
First, props to a great website…this is a very helpful resource! Second, I have a slightly different application. My wife and I are repurposing an old turn of the century salvaged door (that was never hung) into a dining room table. To fill in the low spots (panels), we will be using 1/8 inch layers of epoxy. The epoxy instructions recommend applying a coat of oil based polyurethane to provide adhesion between any old paint and the new epoxy coat. My question is…how long should we wait when going from the poly to the epoxy? I saw your previous reply about waiting 12 hours to go from epoxy to poly…does the reverse still apply?
Hello Corey. Sounds like a cool project! Yes, the reverse holds true as well depending on temperature and humidity. The best way to test to see if it’s ready for the epoxy coat is with the thumb print method. When you press your thumb to the coating it should not feel tacky or leave a thumb print. If it does, then you need to wait a little longer. If it doesn’t, then it’s ready to go.
Hi Shea,
I am converting a bunch of old office buildings into apartments and have completed 6 so far, with 5 more to go. The floors are concrete and I have been painting them. I have tried the Behr Porch and Floor paint and both their 1 and 2 part epoxies and I am disappointed in the results. What I want is a solid color floor with a matte or eggshell or satin finish that will hold up to foot traffic …can I use the porch and floor paint over a concrete primer and then cover that w/ polyurethane? What would you suggest I do to get the finish I am looking for — I don’t like the high gloss look. Thanx, Bob
Hello Bob. Both of the Behr paints you mentioned are made in semi-gloss or gloss only, hence the reason for the shine. Polyurethane floor coatings will not adhere to paint or 1 part epoxy paint. They will adhere to 2-part epoxy coatings however and some are available in clear with a matte finish. This will cut down on the glossy look. Drylok has a latex concrete floor paint that is manufactured in a flat finish that most likely has the look you want. Just click on the link and download their data sheet for more info.
Hi Shea,
Thanks for your quick response. I looked at the Drylock product you mentioned and think it is basically the same as the Behr Porch and Floor paint, since the customer reviews are lackluster and mention scuffing. How about if I use the Behr product to get the color I want, then cover that with a clear 2-part epoxy in matte or satin finish? Do you see any problems with that? If not, can you recommend a good epoxy brand with that kind of finish?
Thanks again.
Hi Bob. We assumed you were aware of those disadvantages with paint since that was primarily what you were using. Keep in mind, you cannot apply epoxy over paint. It can only be applied over another 2-part product.
If you want something that will last and still be somewhat economical, we have a couple of recommendations. You can apply a water based epoxy primer and then a color tinted polyurethane for a top coat. That would be a very long lasting and tough floor for your intended use. The second option would be a single coat of water based epoxy color. Not sure what part of the country you are from, but we would start by calling Sherwin Williams, The Epoxy Superstore, and Legacy Industrial. These are companies that specialize in floor coatings and can do custom tints as well as matte or flat finishes. They are much better than your home improvement centers. Be sure to talk to them and tell them what you are trying to accomplish. The cost may or may not be higher, but you will save in the long run by purchasing in larger containers which you can mix up as you use it, where as buying kits for one floor at a time can be wasteful. When doing larger projects like yours, going this way with the experts is usually the best bet.
We just did our garage floor yesterday with a “2 part expoxy” floor looks amazing except for a little area where the expoxy was not rolled on thick enough. We still have some expoxy left over. Label says it has a pot life of 6 hours, does that mean that after 6 hours it is no good? Could I still roll it on in this little area or just leave it alone? Thanks
Hi Peggy and congratulations on your amazing floor! Unless the remaining epoxy has not been mixed yet, it’s too late to try and apply. The pot life refers to how long the epoxy is workable after it has been mixed. If the remaining epoxy hasn’t been mixed yet, you have 24 hours to re-apply it over the thin area.
The flooring in my living room has hair line cracks – would there be a filler for the cracks prior to either epoxy and PU? Is there a better suggestion (Living room!)
Hello Rodney. For hairline cracks you will want to use an epoxy based crack repair filler. It feathers into the cracks and fills them nicely. This is a good example from Legacy Industrial. If you only have a few, the epoxy crack repair product from Rust-Oleum will do a good job as well.
Hi Shea,
I just had a house built and we are moving in this weekend, the garage slab was poured around April. We have a 3 car garage and I was planning on painting the floor with the store bought brand epoxy’s and topping with a clear coat. I decided after acid washing the entire garage today that I should make sure I buy the right product so my work and hopes for this awesome garage don’t start to peel apart in a few years. After more research on other products I found that I might want to steer clear of some of the store bought brands. I love the poly-urethane look and have decided to go with that, but I’m not sure which one to buy, and if using a primer or an epoxy as an under coat is better, or both. I do almost all of the mechanical work on our cars and use power tools a lot and want to make sure the floor will be strong enough to withstand a lot of wear but look professional. One more thing….. I only have till the end of the week to get this done, I was planning on painting tomorrow morning but it doesn’t look like it now. HELP ME PLEASE!!!!
Hi Jason. Wow, you have tight schedule then. Don’t forget that you can’t move things onto the floor for 48 hours after you are finished and cars at least 72 hours after.
We always recommend primer if you can fit it into the budget. It is the foundation to a long lasting floor. Not knowing what part of the country you are in, you can start by contacting Legacy Industrial and The Epoxy Superstore about quick shipping. They both have good quality polyurethane product. If that isn’t feasible, you can also check with a Sherwin Williams if you have one in your area. They are picky sometimes about selling commercial product to non contractors, but they do have some quality DIY products as well. Their customer service is sometimes spotty though and not as good as the previous 2 companies.
If you don’t have enough time left to get the project done, you may have to load up one side of your garage with your stuff and use your contraction joints as natural borders to do your garage floor in sections. If using a color base coat, be sure to mix all the Part A colored resin together first to insure color uniformity before you start. Good luck!
We painted our covered concrete porch and put the sparkle stuff on it to give it a more marble/terraza look. Can I put clear polyurethane over it to keep it from flaking off?
Hi Jammie. Unfortunately, polyurethane floor coatings will not adhere to paint. If it was an actual 2-part colored epoxy that you applied to the concrete, then you can apply polyurethane. You would need to rough up the surface of the epoxy before applying it.
Hi, good article. This has been very confusing for us. We thought we could just find a product and\or installer to “do the floor” and be done. Who knew there were so many variables!
We are redoing a 10yr old garage and want a nice floor. It sounds like an epoxy product with a poly top coat is the way to go from this article. From reading many many reviews we decided we did not want to do it ourselves due to the failure rate from inproper floor prep. Given our floor has 10 years of stains and was a sloppy wavy pour to begin with we want to find a professional.
Would you be able to recommend a professional installer in my area(St. Louis \ S. Charles, Mo) who would be able to do the proper epoxy \ poly combination install?
Can you still do the chips and \ or grip additives in this scenario?
Hi Nick. Yes, you can do both the color flakes and anti-slip additive with this combination. We are not familiar with installers in your area, but we recommend that you contact Gene Dean of Elite Crete Indiana at info@elitecreteindiana.com He is the Director of Training and Tech support for Indiana and surrounding states. He most likely can recommend a good company in your area to do the install.
Resin floor surfaces happen to be employed for several generations to supply chemically proof protecting coatings, normally for cement bases but also for metal or different houses.
What can you tell me about a hybrid polymer floor coating in a garage. Am trying to decide between that and an epoxy/stone floor. Who knew there were so many choices. Have enjoyed reading all your answers. Thank You.
Hi Bev and thank you from the crew here. Hybrid polymer coatings is a marketing term used by floor coating companies and some manufacturer’s for epoxy. It’s hard to tell you exactly about them without knowing what’s in them because each product is different. Usually however, the term is used for an epoxy coating that has a faster curing time or return to service than typical epoxy. This is an advantage to commercial applicators because they can advertise a quicker return to service. You rarely see this for DIY epoxy products because it is not an advantage to the typical DIY installer because it has to be installed much quicker.
You mention an epoxy process could take 4-5 days. Of the three professional installers I spoke with, one wanted to do polraspartics and said it is all a 1 day process.
The other two wanted to do 2 step epoxy base and poly topcoat but both said done in 2 days. 1 day prep and base coat\chips, day 2 poly topcoat and done. What am I missing that they do it in 3 less days? Should I be concerned?
Hey Nick, you are asking great questions that will benefit the readers here. The primary benefit of polyurea and polyaspartic coatings is the fast cure times which provide for a quick return to service. Most can be driven on 24 hours after the last coat was applied. Good installers can prep a floor in a few hours with the right equipment. After the first coat is applied, the second can usually be applied after an hour or so, thus resulting in a 2 coat application all done in 1 day and able to drive on at the end of the next.
Installers will sometimes add accelerants to epoxy and polyurethane that will enable them to apply the next coat about 2-4 hours after the previous coat was applied. These don’t work well for the DIY crowd because it reduces the pot life of the product and has to be applied quickly by a team of 2-3 people. It does reduce the amount of time required to install the coatings however. Be aware though that you still need to wait longer for it to fully cure before you drive on it unlike polyurea and polyaspartic coatings.
I want to place a vinyl print of a famous painting on a new cement floor in a bedroom. Will the polyurethane react with the vinyl and damage the picture, or can you give me a recommendation for a clear topcoat thate would not react with the vinyl. Ben
Hi Ben. Installing vinyl floor graphics requires a bit of work. Epoxy and polyurethane both work fine with vinyl. It’s best to use a graphic that is breathable. If it’s not, the graphic doesn’t adhere as well to the base coat and can develop bubbles. The process usually involves putting an epoxy primer down first, then the graphic, followed by a coat of epoxy, and then polyurethane. Here is a good example from FloorPix. For a bedroom you don’t need as many coats and the epoxy doesn’t have to be applied as thick, but the process remains the same.
Hi
I’m looking for a high gloss look on the concrete floor of my mancave. This slab has in-floor radiant heat. Would there be any issues with a clear epoxy/polyurethane combo over a heated floor?
Thanks for your help.
No, not at all. In-floor radiant heat works just fine with with epoxy and polyurethane both.
A great website and very needed. We have a 10 year old garage floor with double bubble foil backed insulation between the concrete and the ground. I mention this because of all the moisture problems I’ve heard about relating to epoxy bonding. I have two competing technical companies that use polyaspartic as a top coat. One uses a hybrid approach applying epoxy as a base coat, because it claims it is far superior to polyaspartic for bonding to cement, and two polyaspartic top coats. The reason they give is that the polyaspartic cures too fast to penetrate the concrete and bond sufficiently, hence using the epoxy as the bonding agent to the concrete. The response from the other company is they have a confidential formula that balances the penetration of the polyaspartic into the concrete by adding a secret amount of wetting agent that help the polyaspartic penetrate deeply into the cement. They say it takes two to three days to dry before you can ride your car on it. So the fast cure of the polyaspartic is not so fast. This company uses a total of two coats of polyaspartic. It is confusing trying to decide which is the best process given all the variables. I’m not concerned about time only which process is superior? I’ve also heard about solids content and 100% solids are superior. Is 97.3% solids drastically inferior to 100% solids? Where do you draw the line? Are there any pragmatic adhesion numbers for each process, instead of verbal statements, which mean nothing, available and where would I find them? Thanks you in advance for your answers.
Hello Jay and thanks for the kudos. Yes, polyaspartic coatings do not soak into the concrete as well as epoxy due to the fast cure times. It’s not uncommon now for polyaspartic/polyurea manufacturers to add wetting agents to the base coat to get better penetration. It shouldn’t take 3 days to cure however. 9 times out of 10 epoxy is the better alternative when it comes to bond strength, but it doesn’t mean that the polyaspartic coatings will delaminate. Bond strength is measured as the amount of force in PSI that it takes to separate a coating from a substrate. Generally the amount of force required to separate will pull chunks of the concrete up with it. So a force of 400 PSI vs 600 PSI that both pull concrete up with it doesn’t mean one is worse than the other. It just means that the higher bond strength pulls up more concrete. If you had hydrostatic moisture issues to worry about, then these numbers would be much more significant. What adhesion many times comes down to is how well the floor was prepared. If not done properly, the best coating will still peel up.
The place to get the information is from the Technical Data Sheets for the product. Ask for the TDS directly or the name of the products used in order to find them online. 100% solids epoxy is always +/- 2% so a 97% solids is close to the same. We are not saying the second company’s floor coating is not good, it just sounds to us like the first company is offering a top notch system, using an epoxy as a primer to ensure the best adhesion possible.