February 7, 2023

The Deal with Oil-Based and Water-Based Polyurethane Flooring Finishes

Painted wooden board with transparent protective water-based finish.

Finishes are one of the things that help hardwood floors’ long-lasting performance and appearance. A finish acts like a coat of armor for your hardwood flooring, protecting the surface of your floorboards from any damage. There are many hardwood finishes available, but polyurethane coats are the top choice for many homeowners and remodelers. Like other options, polyurethane has oil-based and water-based varieties. Find the difference between the two with this guide about polyurethane hardwood floor finishes.

What is a Polyurethane Finish?

Polyurethane is a liquid plastic finish often applied on hardwood floors. They’re one of the most durable top-quality finishes and are tougher than shellac and varnish. Once it dries, the flooring becomes more resistant to water, solvents, abrasions, and other wear and tear, unlike many traditional varnishes.

While many compare them to varnishes, shellac, and lacquer, polyurethane finishes are popular because of their composition. Unlike other finishes, polyurethanes are pure plastic that works well on interior applications. They create a protective layer of plastic while bringing out the planks’ graining and leaves a golden hue.

Polyurethane finishes come in either water-based or oil-based solutions. In addition, they provide different sheen, depending on your need. Homeowners often choose from gloss, semi-gloss, and satin sheens when using this finish. But it’s best to remember that glossier finishes show underlying imperfections more than other options.

One of the upsides of using polyurethane finishes is their versatility. Besides having numerous options on the sheen, solution, and application, they’re also great for outdoor flooring spaces. When it comes to applicators, remodelers can use a range of materials or purchase spray-on poly.

Oil-Based Polyurethane Finishes

Oil-based polyurethane finish was the earlier solution for a finish before water-based polishes became popular. It uses different petroleum and mineral solvents to hold the necessary polyurethane solids. Unlike oil-based paints, many homeowners across the country still use and sell these coats.

This finish is available in either spray or brush-on formats that create a hard, protective shell with fewer coatings than its water-based counterpart. But it leaves a reddish or yellowish sheen on your hardwood floors over time, especially after numerous coats. But some remodelers do it on purpose to achieve a specific look.

Drying/Curing Time

One of the notable differences between oil-based and water-based polyurethane finishes is their drying time. Oil-based polyurethane dries slowly, and one coating needs two hours to dry out. In addition, the more coats you add, the longer the process will take. On average, a reasonable layer of this finish takes six hours before people can walk on them. But the time will still depend on your room’s condition.


Besides the time it needs to dry up, oil-based finishes have a sharp and pronounced smell. Many people find the odor unpleasant, and the fumes have unhealthy side effects. Unlike water-based polyurethane, the oil-based solution has high levels of VOCs. Volatile organic compounds, or VOCs, are compounds the finish emits after applying them on your hardwood floors.

Exposure to VOCs can irritate your eyes, nose, and throat. It also causes breathing difficulties and nausea. Severe effects of the compound on the body can lead to central nervous system damage, organ failure, and cancer.

Once the finishes dry out, the odor is also gone, but there are instances that fumes remain even after six hours. Due to this, many remodelers leave a refinished room for at least a day to cure and the smell removed.

Clean Up and Leveling

Oil-based polyurethane is self-leveling. Unlike other finishes, they become smooth when you apply them to a horizontal surface. Cleaning after this solution can be tedious as homeowners need mineral spirits or paint thinners to remove unwanted splashes or applications. 

Water-Based Polyurethane Finishes

Water-based polyurethane hardwood finishes use water instead of solvents to carry polyurethane solids. While they form a similar hard protective layer, it requires more applications to recreate the effect. In addition, they’re also a newer solution to combat VOC emissions and keep your home’s indoor air in good quality.

Drying/Curing Time

Water-based polyurethane finish dries faster, but it requires more coat application to achieve the best protective layer for your flooring. Despite that, it takes lesser waiting time for the hardwood floorboards to dry out.

Unlike the oil-based solution’s sticky, honey-like appearance, its water-based counterpart has a milky-white look that will clear as it dries up. It imparts little to no color on your flooring and doesn’t turn yellow over time.


Water-based polyurethanes have little to no odor. While it emits VOCs like the oil-based option, they contain smaller amounts and disperse into the air quickly. Although its VOC levels are low, many experts suggest remodelers wear masks when applying the finish on their hardwood floors.

Clean Up and Leveling

Like oil-based polyurethane, their water-based solution is self-leveling. They’re smooth to apply on horizontal surfaces despite brushing more of it to produce the best results. Because they use water as a base, cleaning splashes and other messes is manageable with soap and warm water.

Water-based polyurethane finishes are great for people who dislike messy, foul-smelling coats. In addition, homeowners who need a thinner and more flexible finish can find these polyurethane polishes perfect for them.

Checking the Best Hardwood Floor Refinishing Services in Austin, TX

Finishes are hardwood flooring must-haves every hardwood floor owner should consider. Applying the best coat on wooden floors can prolong their performance and appearance. Among the many finishing options available, oil-based and water-based polyurethane coatings are the most popular. Despite providing the same hard plastic layer of protection, understanding the difference between the two can help you choose which is better for your hardwood floorings.

Talk with the best wood floor refinishing service in Austin, TX, for more information. Call Kelly Hardwood Floors today!