Oil vs water-based polyurethane for oak floors

Our home office remodel is s-l-o-w-l-y coming along and I’m loving my refinished hardwood floors – they started out all scratched and orangey but now… gorgeous!

This is the fourth time that we’ve had hardwood floors refinished in our house – it would have been so much easier and less expensive to have done all of the hardwoods at once but unfortunately I didn’t have that foresight before we moved in.  The first hardwoods that we refinished were in our kitchen where we used oil based polyurethane, but for all of our refinishing jobs since then we’ve gone with water based.  There are pros and cons to each so I thought I’d share what I’ve learned when making my decision between these two types of polyurethane. 

The major differences to consider are: 

Drying Time

Water-based polyurethane dries much faster than oil-based polyurethane.  With oil-based, you typically have to wait until the next day to add another coat of polyurethane, but water-based polyurethane can be recoated in as soon as 2-3 hours. Since refinishing wood floors involves multiple coats of polyurethane, this means that the total time of your refinishing job is longer with the oil-based. Also, once the last coat of polyurethane has been placed on the floor, the time before you can walk on your floors and put your furniture and rugs back is much shorter with water-based polyurethane.  When we refinished our wood stairs, I decided water-based polyurethane was a must because otherwise we couldn’t get to any of our bedrooms or full baths and would need to sleep somewhere else for a few nights. By using water-based polyurethane, by the end of the day we were able to walk up our stairs in socks and sleep in our own beds.

Odor

Oil-based polyurethane is much higher in VOCs so it has a strong odor and is not environmentally friendly whereas water-based polyurethane is a low VOC product with little to no smell.  The odor and possible health effects of using a high VOC product should always be considered, but especially if you’re refinishing hardwood floors in the winter when you can’t air the house out well. When we refinished our kitchen floors with oil-based polyurethane, it was the middle of winter and our house reeked! We made the mistake of sleeping in the house the first night that the floors were polyurethaned and it was terrible – I couldn’t sleep due to the awful smell and my worry about what my kids were breathing in. 

Color

Floors that are finished with oil-based polyurethane tend to amber (turn an orangey yellow) over time whereas floors finished with water-based polyurethane are not expected to change color with age. Some people like the rich ambering that occurs with oil-based polyurethane and feel that this type of polyurethane adds more richness and depth to the floors whereas others don’t appreciate the change in color.  

Cost

Water-based polyurethane is a more expensive product than oil-based polyurethane.  However, some companies don’t charge a whole lot more for water-based polyurethane because there is less drying time between coats, allowing them to get your job done faster and move on to the next job.  When I’ve gotten bids for hardwood refinishing, I found that the added cost of water-based polyurethane varied greatly from company to company.

Durability

I’ve come across all sorts of different opinions about the durability difference between oil-based and water-based polyurethane.  Some refinishers feel that oil-based polyurethane is more durable.  Others feel that the durability is fairly equal if you are using a high quality water-based polyurethane.

So you’ve probably guessed my preference by now – I like using water-based polyurethane. For me, the extra cost of water-based polyurethane is worth it due to the faster drying time, lower VOCs, and low odor.  For the type of floors that we have, I also like that the color doesn’t change over time, as our floors that were finished with oil-based polyurethane years before we moved into the house look downright orange. Have you tried both types of poly and, if so, which type would you use the next time your refinish your floors?

Welcome back to another round of Ask the Home Flooring Pros. Following our recent post on maple flooring we had a question from a reader in Texas asking us to explain more clearly the difference between water based and oil based polyurethane and to outline the pros and cons of each. So lets compare and contrast these two types of polyurethane and see how they match up.

HOW WATER BASED AND OIL BASED POLYURETHANE ARE THE SAME

The difference between water based and oil based polyurethanes isn’t one of better and worse. We use both types with excellent results. It’s the project, not the product, that determines our choice.

Oil-based finishes were once more durable, but the new generation of water-based polyurethane is remarkably hard and long-lasting. There is no discernible difference in how long they last. Also, professionally finished floors should feel satiny smooth, whether the finish is oil or water based. Click here if you want to learn how to keep your wood floors smooth and shiny.

HOW WATER BASED AND OIL BASED POLYURETHANE ARE DIFFERENT

Let’s cover a few basics before discussing which is best for specific wood types.

Drying time:

• Water based polyurethane can be recoated in 4-6 hours. Up to 4 coats can be applied in a day. Furniture shouldn’t be placed on the flooring for 12 hours after the last coat is applied.
• Oil based poly can be applied in just one or two coats per day depending on the product instructions on the can. Wait 24 hours after the last coat to walk on it and 48 hours before moving furniture back into the room.
• Pro tip: Speaking of coats, oil based polyurethane has more solids than water based finish, so just two coats are required. We recommend three coats of water based poly.

For more detailed info on polyurethane drying times click here

Fumes/Odor:

• Water based finish has a light odor. No respirator is required, but you might want to crack a couple windows for fresh air.
• Oil based polyurethane has a strong, fumy odor. We recommend wearing a respirator and keeping pets and anyone with breathing issues away from the smell. Keep the area ventilated. The odor will linger until the polyurethane is fully cured in a couple days.

Durability: While both are long-lasting, there is a difference in how they wear and what you can do to protect the finish.

• Water based poly is harder, so it is more susceptible to surface abrasion caused by fine debris. For this reason, vacuum your flooring regularly using a hardwood floor vacuum.
• Oil based finishes are softer, so they don’t scratch as easily, but they dent more readily. While keeping debris off the flooring is still a good idea, it’s also important to put pads under furniture feet to prevent denting.

Look: These finishes look different when applied and even more so as they age.

• Water based polyurethane dries clear and remains clear.
• Oil based poly has an amber tone that immediately darkens the wood. As it ages, the amber hue deepens.

Cost: Water based polyurethane cost is two to three times higher than oil based products. When cost and coats are calculated, this works out to about 35 to 50 cents per square foot for oil based poly and 80 cents to $1.35 per square foot for water based polyurethane. Well known brands like Minwax produce both types of poly making it easier to compare prices.

YOUR FLOOR IS THE DECIDING FACTOR

The look is what matters. Drying times, odor and cost are negligible factors when deciding whether to use water based vs. oil based polyurethane. The smell will be gone in a week. You’ll live with the look for a decade or more.

Will your wood look better with a clear coat or an amber coat? Here’s what we recommend.

Water based polyurethane: If you want your floor to stay the same color, choose water-based polyurethane. Wood that is gray, white or light looks better with a clear coat, i.e., a water based finish. Woods with a hint of yellow in them already, such as pine, fir and ash, become even yellower with an oil-based finish. Go with water based poly if that’s a look you want to avoid, or choose an oil based finish to enhance it.

Oil based polyurethane: Darker wood tones are enriched by an amber hue and an oily sheen. Oil based polyurethane can bring out the vibrant color in red oak, cherry or exotic woods like teak.

Looking for wood floor stain color ideas?

SETTLING THE WATER BASED VS OIL BASED POLYURETHANE FINISH DEBATE

Quarts of both finishes are relatively cheap compared with the cost of redoing a floor you believe would look better with a different finish, an unpleasant position to be in. The quandary is easy to avoid with this method:

1. Buy a quart of water based poly and a quart of oil based poly
2. Select two or three pieces of your flooring with differing looks (pieces with or without knots or wide grain and narrow grain, for example)
3. Finish half of each piece with the oil based poly and the other half with the water based finish
4. Apply a second coat, and wait 24 hours for them to dry/cure
5. Give yourself a few days to compare the looks, view them against wall colors and furniture and decide which you prefer

With this approach, the decision about whether to use oil based polyurethane or water based polyurethane will no longer be hypothetical. You’ll have tangible finished flooring samples you can see, feel and run your feet over, if you want. Your decision will be much easier when you do.

Now you’ve chosen your finish you should check out our guide on how to apply polyurethane.

About the Author:

Rob Parsell

“I’m the son of an interior designer and picked up an eye for design as a result. I started hanging wallpaper and painting at 14 and learned enough on the job to be the general contractor on two homes we built for our family and did much of the finish plumbing, electrical, painting, and trim work myself.”

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