Hardwood floor finishes come in a number of different varieties, so it’s important to know when to use a certain type and not another.
Here’s a rundown of the most common types of finish you’ll find, and the features of each.
Oil-based finish
A very popular finish choice, especially for commercial and sports floor settings. Oil-based polyurethane requires a long drying time between coats: most varieties take 8 to 10 hours to dry. Oil-based poly has a high VOC content and a strong odor when applied. Very durable. Tends to turn a yellow or amber color with age.
Water-based finish
Has a lower VOC content, a milder odor, and requires less drying time than oil-based poly. Most varieties require just two to four hours of drying time between coats. Doesn’t yellow as much as oil-based polys do. Water-based polyurethane usually requires the application of more coats than oil-based finish does. Available in single-component and two-component varieties. More expensive than oil-based poly finishes.
Moisture-cured polyurethane
This type of finish cures by absorbing moisture vapor from the air. Extremely high VOC content and very strong fumes––proper ventilation and respirators are required during application. Extremely durable. It’s more water-resistant than most other finishes. Most formulas amber with age. Relatively expensive compared to other finishes.
Penetrating oil / sealer
As the name suggests, this type of finish penetrates the wood and fills the pores to create a durable seal. Penetrating oil consists of a blend of natural oils, usually including tung oil. Tends to turn an amber color over time. Very durable. Mild odor, low VOC, mellow sheen. Simple to apply and touch up. Needs long drying times between coats––usually 24 to 48 hours––but will turn whitish in color if it is allowed to dry too quickly. Penetrating oil is good for use on antique flooring.
Acid-cured / Swedish finishes
Among the most durable types of floor finishes. Extremely high VOC content. Takes about two hours to dry in between coats, and takes up to 60 days to fully cure.
Wax
This was a common hardwood floor finish of choice before polyurethane finishes were created. Wax seeps into the pores of the wood to give it extra durability, but it’s vulnerable to water damage. Wax needs regular maintenance and is not as durable as poly. Low luster, amber appearance. Tends to darken the wood. Low VOC content.
Shellac
Usually used in conjunction with wax; shellac is applied to the floor as a base coat and wax is applied on top. Some shellac products are not compatible with modern types of finish, so a floor that contains shellac should be tested before anything new is applied to it. Test adhesion of the finish you want to apply. Shellac is non-toxic and has a very low VOC content. It is available in “dewaxed” form from a variety of manufacturers. Shellac is not easy to apply. Shellac doesn’t require buffing between coats and dries very quickly. However, it’s not as durable as polyurethane finishes, and it’s vulnerable to damage from water, alcohol, and ammonia.
Varnish
Varnish was commonly used to finish wood floors before polyurethane was introduced to the market. Very durable. Gives the floor a clear to slightly amber look. Very strong odor, and has a high VOC content.
Acrylic impregnated finish
Rarely used in residential settings, this finish is injected straight into the floor in order to create an extremely durable seal. Primarily used in commercial areas that have to endure heavy foot traffic.
City Floor Supply stocks a variety of different finishes to suit your needs. View our selection of hardwood floor finishes.
Thank you for explaining that a penetrating oil or sealer will need at least 24-48 hours to dry between coats. My friend was talking about wanting this for her floors to make them a bit more durable. I think that the dry time is something that she’ll need to keep in mind so that it can work effectively.