Varnish Vs Polyurethane for Hardwood Floors

If you have recently installed a new hardwood floor in your home, or you’re planning to do so in the next few months, then you most likely know that there are steps that need to be taken to protect the integrity of your brand new floor. There’s no point in installing a new floor if you’re not going to protect it properly, so one of those steps is putting several coats of finish onto your floors to ensure that they’re safe from scratches, stains, and UV rays. With that being said, it’s important to know what type of finish you want to put on your floors before you jump into a project that you’re not exactly ready to tackle.

There are two main types of finish that people use on their floors, and those are polyurethane and varnish. If you’ve recently installed new hardwood floors in your home, or you’re getting ready to complete the project, then keep reading to find out which finish would be the best one for you to use and why.

What is Polyurethane?

how to apply water based polyurethane to wood floors

Polyurethane is a water or oil-based liquid that turns into a hard coating once it is applied and dried. Polyurethane can be used to finish and protect hardwood floors. People typically choose to use polyurethane on their floors because it’s usually an easy and forgiving process, which is pretty important when you’re a novice DIY-er. If you choose to use polyurethane on your floors, keep in mind that oil-based polyurethane offers more protection to the wood, but it is more toxic and it takes much longer to dry, as well.

Let’s Talk About Varnish

Varnish is a natural wood finish that has been around for as long as any of us can remember. Made from resins, oils, and solvents, varnish contains a much higher amount of solids, and it is capable of giving wood a nice tinted color when it’s applied. At times, all wood finishes are referred to as varnish, so make sure that you pay attention to what you’re buying before applying it to your floor.

Now that you understand what varnish and polyurethane are, let’s take some time to go into further detail about the two. This will allow you to make an educated decision on which option you would like to use on your own floors, so you don’t accidentally use the wrong product.


It goes without saying that people choose to finish their hardwood floors because they want them to be more durable and protected against wear and tear from everyday life. Fortunately, varnish and polyurethane can get the job done without any problems, as long as they’re applied correctly, of course.

Polyurethane finishes are extremely hard and durable, which is great when you have a messy or busy family at home. Because polyurethane cures into a solid layer of plastic, it allows the wood floor to have a thick layer of protection against scratches and abrasions. You should also keep in mind that if you’re looking for a strong, durable product, then you should consider using an oil-based polyurethane instead of water-based. Unfortunately, because polyurethane dries into a hard plastic film, it can split or crack if it’s subjected to heat or sudden shocks.

On the other hand, varnish, which is more flexible, actually helps reduce cracking and splitting if there is any type of movement on the surface. Since varnish has a higher amount of solids, it is naturally resistant to UV rays, making varnish perfect for surfaces that are exposed to sunlight.


If you’ve ever worked with polyurethane before, then you already know that you should take precautions against inhaling the fumes or allowing your skin to be exposed to the product. While this is especially true with oil-based polyurethane, water-based polyurethane may have a lower toxicity, but precautions should still be taken to avoid inhaling the product. Fortunately, when compared to polyurethane, varnish has a very low toxicity level, so if you have kids at home, varnish might be the best choice for you to make.

Best Uses for Polyurethane

Obviously, with so many options like sheen, flat or glossy, it can be difficult to choose the right polyurethane for the job. A lot of times choosing the right polyurethane breaks down to personal preference, but there are definitely circumstances when one is better than the other.

For indoor use, like pieces of furniture, completely clear when dry, water-based polyurethane is the best option. This type of polyurethane enhances the natural hue of wood, which makes it the perfect choice for a piece of furniture that just needs a little pick-me-up. Also, if you’re looking for an easy-to-use and easy-to-clean option, then water-based polyurethane would be perfect for you.

If you’re looking to finish your hardwood floors, then you might want to consider using a water-based oil-modified polyurethane. This type of polyurethane provides a stronger level of protection than traditional water-based polyurethane. Unfortunately, because water-based polyurethane is more prone to cracking from heat damage, it shouldn’t be used on wood carvings or anything that will be exposed to the elements.

Best Uses for Varnish

Because varnish has a high solid content and it’s highly water-resistant, varnish is the perfect option for anything exposed to the elements, such as decks, boats, and outdoor chairs. You can also purchase varnish known as spar or marine varnish, which provides UV protection, as well as, flexibility. Also, varnish has a much lower toxicity level than polyurethane, so it can be used around entryways and window frames without having to worry about the toxic fumes.

As you can see, varnish and polyurethane certainly have their own positive qualities. At the end of the day, the protection you use on your floors is almost entirely dependent on your own personal preferences. Make sure to do a bit more research so that you know exactly what it is that you’re looking for, and you should have no problem protecting your floors for many years to come.