There are so many factors to consider when planning for a hardwood floor — wood type, stain, location, board width … it’s easy to forget. One factor not to miss is what type of polyurethane finish you choose.
Some people may swear by oil-based finish, while others stand up for water-based. Both have their benefits and drawbacks, and depending on the look you’re going for and the room you’re considering, one may be better than the other.
What’s the difference?
Polyurethane is a polymer compound that, depending on its structure, can be used to make anything from rigid foam installation panels to sponges. In the case of sealants, the polyurethane compound is combined into a liquid form with a base such as oil or water and solvents. Water-based polyurethane is only partially based on water, as it is the liquid carrier that then evaporates off, leaving a hard resin finish.
Both can successfully seal your wood floor but they have some major differences in durability, color, hardness and cost. In some cases, your installer will recommend one over the other because of the function or color of your floor, but often the choice is up to you.
As elsewhere, oil is thicker and more viscous than water. Oil-based polyurethane will be thicker and lend depth to the color as well as a vibrant shine to floors. Water-based polyurethane, then, will be thinner and have less shine.
However, it does have the advantage in the long run. Oil-based poly will gradually gain an amber glow and yellow over time, while water-based poly will retain its color. If you are planning a floor with light-toned wood such as maple or a light tone, such as gray or white, you have to use a water-based finish for the best look. The same goes for woods like ash or pine that have a natural yellow color — an oil-based finish would bring up the yellow notes even more while the water-based finish will let only the natural color through.
Finish is meant to take all the beating so the wood doesn’t have to, but oil and water-based finishes take the damage in different ways. Oil-based finish is thicker and softer, and is susceptible to dents; water-based is harder, thinner and may shows more scratches. Manufacturers make different blends of finishes, such as a high-traffic water-based finish, depending on the customer’s needs. It’s important to consider the activity level or traffic in a room before planning wood types and finishes. We recommend three layers of Bona Traffic High Durability water-based finish or three layers of an oil-based finish.
As the name implies, applying finish is the last stage of installing a hardwood floor. The wood is typically already in your home at this point, with the exception of prefinished floors. One thing to consider, then, is the time it takes to apply coatings and the smell.
Oil-based polyurethanes, like many other oil products, have a strong smell. The fumes can be noxious, and installers often wear masks while using it to protect themselves. Clients usually remove pets and leave while the oil-based finish is being applied and drying and curing, which can take about 24 hour per coat. We always apply three coats of finish, which provides the most durability.
Water-based finishes, on the other hand, have very little smell, and it’s safe for people and pets to stay in the home while they are being applied. The drying and curing process is faster as well — homeowners can walk on the surface in socks as soon as four hours after the last coat has been applied.
Price and value
Water-based polyurethane finishes are significantly more expensive. If a contractor offers a water-based finish on a job for no extra cost, question it! They may be using a cheap brand that will not last. We recommend only Bona brands, as they provide the most durability.
Most of our customers choose water-based finishes, as they have almost no smell and the resulting seal is clearer. It’s lighter and duller, matching the lighter-color floors that are popular in new designs. It is more expensive, but it is hard and durable and less susceptible to dent.
Oil-based finishes are more traditional, less expensive and have value for shine and color, but dent and tend to yellow and darken over time. The choice is ultimately up to the customer, but it’s important to understand the full pros and cons of both types.