Water Vs Oil Based Polyurethane
Which is the better finish to use on hardwood floors, water-based or oil-based polyurethane? For anyone that has been through the process of installing or paying for the installation of a new hardwood floor, the question of which type of polyurethane finish to use has undoubtedly come up. Hardwood floors take a lot of abuse from pets and families, to business traffic. If you want to properly protect your beautiful new floor install, it is imperative that you apply a finishing product. There are of course pro’s and con’s to each type of finish. Which finish is ultimately the best depends on a number of factors.
What is Polyurethane?
Polyurethane: Poly meaning many and urethane which is a catchall term for different types of resin ie. poly-esters. poly-carbonates, poly-ethers etc. The different structures or functionalities are responsible for the wide variation in performance such as: foams to flexible coatings for leather or vinyl to hard coatings for wood floors and even harder thermal cast products such as plastic i.e., skateboard wheels and shopping cart wheels.
Water-based Polyurethane Finishes
Most water-based finishes dry clear and do not change color over time. The “yellowing” of the floor’s color often seen with oil-based polyurethanes won’t happen with water-based. There are water-based products that are made to mimic the ambering effect of oi-based finishes. Traditional dark floors are giving way to light natural floors and if your floor is going to be on the lighter side in terms of the color, you’ll most likely want to choose a water-based poly. Water-based finishes also offer lower sheen options like matte and low satin sheens.
Water-based finishes take 2-4 hours to dry so two coats can be applied on the same day. If you are an installer/finisher this means you’ll be able to finish projects faster than if you decide to use an oil-based poly. As the cure time for water is faster, this also means the home owner can move furniture and area rugs into the room quicker than if an oil-based polyurethane was used.
Water-based finish odors are less offensive than oils. In fact, water-based polyurethanes have virtually no smell or “off-gassing”. Oftentimes home owners will even choose to stay at home during the process of applying a water-based finish. For those of you that have experienced the intense smells associated with oil-based finishes, you know how much of an advantage this can be.
The environmental impact of using Water-based polyurethane is mostly evident during the drying time of water vs. oil. With lower Volatile Organic Compounds (VOC’s) at 100 to 275 grams per liter, water is a greener option and is safer for the environment. Traditionally, products used for finishing have had VOC content as high as 750g/L!
Oil-based Polyurethane Finishes
Oil-based finish has been around a lot longer than the water-based finishes. Oil-based finish is good for older, more traditional looking floors. Floors that are dark brown, golden brown and even red can look good with an oil-based finish. Oil-based finishes start out with a slight amber color and then continue to darken and yellow with age.
Oil-based finish coats take 8 hours to dry in perfect conditions. This means you can only apply one coat a day. So, for those of you that are looking to have the job done quickly, jobs done using oil will take longer than water-based finishes. Contractors usually apply two, or maybe three coats of oil finish over stain or sealer. This means it will take more product to properly finish the sealing job. The curing time for oil-based finishes is significantly longer than water-based. For homeowners that means a longer wait time before placing furniture and area rugs.
Oil-based finish has a fairly strong oil modified solvent smell that will linger for at least a couple of weeks. Homeowners may not want to stay in the house while the process is going on. If the homeowner is sensitive to smells or has bad allergies, there is a very good chance they will not be physically able to remain in the house during this phase.
Oil-based finish measures around 450 to 500 VOC’s grams per liter. Whereas water-based finish is around 150 to 275 VOC’s. In some states and counties, oil-based finishes no longer meet air quality mandates and therefore cannot be legally used as applicants. In many new builds, water-based will be the preferred or required applicant due to the more positive environmental impact.
The Durability of Water-based Polyurethane compared to oil-based
Durability is likely the number one question asked when comparing water-based vs oil-based hardwood floor finishes. If you scour the web you will find a lot of information that oil-based finishes are more durable than water-based finishes, citing build and solid content. This may have been true 15 years ago, but it is no longer the case. Waterborne resin and polymer technology have come a long way in addition to the improved application characteristics. Water-based hardwood floor finish is a lot harder and more chemical resistant whereas oil-based hardwood floor finishes are softer and less chemical resistant. Waterborne technology offers both single component and 2 component options, 2 components being the most durable of the two.
If you are a contractor or homeowner that is wondering whether to use a water-based or oil-based finish, the clear choice would be to use a water-based application. Water-based polyurethane finishes, provide a more consistent appearance, dry just as hard and wear-resistant as oil-based alternatives, are better for the environment and don’t emit nearly the same level of off-gassing smells.
Advantage Coatings Technologies is a market leader in water-based finishes. If you are considering using a top-of-the-line finish for your next project, we hope you’ll contact us. Our in-house technicians are highly knowledgeable about everything finish related and can help you choose the right product. You can reach us Monday-Friday at (303) 499-1310 or contact us online here.