Epoxy VS Polyurethane
Epoxy VS Polyurethane is a question that always comes up when deciding on what materials we recommend 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 floors against stains, damage, chemicals, oils and wear. They are both long lasting, light reflective and easy to clean. They also have their own advantages depending on the application. So which one is best for your project? Both, I'll explain why.
Epoxy is a thermosetting polymer which is available in three different formulations, water based, solvent based and 100% solids. The different formulations allow for different degrees of thickness from 3 mils to over 10 mils for a single coating. They also allow for ease of applications, 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 floor surface.
The best epoxy formulation are 100% solids and provide for an extremely hard, thick and impact resistant surface. This self-leveling contributes to the 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. Even 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 fir any length of time. This is something to consider when choosing a floor finish.
Polyurethane is a also a thermosetting polymer and is considered a high performance coating. It is commonly know as urethane for short. A polyurethane coating is about 2 mils to 3 mills in thickness and can't be adjusted as with epoxy.
Don't let the thinner dry thickness fool you however. 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 the wear resistance of polyurethane is 3x stronger than epoxy. 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 is that it is UV stable. Meaning it won't yellow like epoxy does when exposed to small amounts of sunlight over a period of time. The surface 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.
So which one should you use? Both, the best systems usually are a combination of epoxy primers and skim coat and polyurethane top coating.