Types of Wood Floor Finishes

Oil-Modified Urethane

Oil-modified urethane ambers with age, is easy to apply and is available in different sheen levels.  It only takes eight hours to dry.  It's one of the more popularly used finishes because it is durable and moisture resistant.  The durability and moisture protection comes from its petroleum base, which is blended with synthetic resins and plasticizers, but it is a solvent-based polyurethane. . 

Moisture-Cured Urethane

Moisture-cured urethane comes in a satin or gloss finish, and in non-yellowing or ambering types.  It is somewhat challenging to apply, and the fumes are very strong, however, it is one of the more durable and moisture resistant finishes.  Just like an oil-modified urethane, it is a solvent based polyurethane.   Humidity will be a large factor in the drying time.

Water-Based Urethane

Water-based urethane only takes two to three hours to dry, but it is a more expensive type of urethane.  The fumes are not as strong as other finishes, and it is a durable and moisture-resistant finish.  Water-based urethane finishes are available in various sheen levels, and are clear and non-yellowing.  It's made from a water-borne urethane that is blended with synthetic resins, plasticizers and other ingredients. 

Conversion Varnish Sealers (Swedish Finishes)

Swedish Finishes and conversion varnish sealers are terms that describe a two-component acid-curing alcohol-based sealer.  Since it originated in Sweden, the longer name of “conversion varnish sealer” has given way to the shorter term “Swedish Finish.”

Penetrating Sealers

Penetrating Sealers are solvent based, usually colored, and are used to stain and seal wood floors.   They are made from tung or linseed oil.  Additives help the sealer dry faster and harder.  Penetrating sealers are spread on the floor and then left to sit and penetrate, hence, their name.  The excess sealer is then removed or buffed off.

Paste Wax

Paste Wax is a classic material for surface protection after a stain and/or sealer is applied.  It's very easy to apply, easy to fix, inexpensive, dries fast and has an incredibly long lifespan.  You simply spread it on then buff it to the sheen you want.

Varnish

Varnish is spread to provide a hard coating. The use of natural varnish has waned since urethane finishes were introduced.  Vinyl-alkyd varnishes are more popular than natural varnish.

Lacquer

Lacquer is highly flammable and never recommended as a finish.

Shellac

Shellac can be found with or without wax.  Natural shellac, with wax, is not often used for wood flooring, however dewaxed shellac is used as a wood floor sealer.

NOTE:  When you inspect your wood floor, look at it from a viewpoint that is five feet up and two feet away.  Make sure there is no glare from windows or lighting, or the irregularities will be misrepresented.  Viewing it in normal lighting conditions is the preferable option. 

What Finish - What wood floor products? Commonly used wood floor finishes:

Pre-finished Hardwood Flooring (Factory Finished Wood Floors – Before Installation)

Acrylic Impregnated – The wood is injected with an acrylic monomer.  This invades the cell structure of the wood and increases the wood's hardness.  The wood is finished with a wear layer.

Acrylic-urethane – Very similar to polyurethane, but has a slightly different chemical makeup.

Aluminum Oxide -  The abrasion resistance of the wood is increased by adding particles to the polyurethane finish.  Used frequently on high grade hardwood floors.

Ceramic – An added technological process which uses ceramics to increase abrasion resistance.

Polyurethane – A well-known wear layer used in many applications that is clear, tough and durable.

UV-Cured – Instead of finishing wood with the commonly used process of heat,  a UV-cured wood and its polyurethane finish are finished with ultraviolet lights. 

Job Site Refinishing – This simply means that an unfinished floor will be finished on-site.  For instance, the sanding and staining will take place at your home instead of the factory.  Job Site Refinishing is used for custom jobs.  Your wood floor finish will need to be appropriately matched to the species of wood you have chosen or the finish may not take.

Moisture-Cured Urethane – Similar to solvent-based urethanes, but needs moisture to cure properly.

Solvent-Based Urethane -  A polyurethane finish with oil components.  Needs at minimum 24 hours to dry.

Water Based Urethane (Latex) – A polyurethane finish with water as a component.  Only takes two to six hours to dry.

NOTE: Sunlight can discolor a finish.  After finishing keep the drapes closed and wait at least a month before you replace any area rugs.  Once it is fully cured it will be less sensitive, but can still discolor from excessive UV rays.  

What type of finish do you have?

You can determine the type of finish on your floor (or at least make an educated guess) by trying some of these simple tests:

Think about the age of your floor.  For the most part, only varnish or shellac was used before the mid 60s. 

To test whether it is varnish or shellac, scratch the floor with a coin in an inconspicuous spot.  A flaky finish indicates that your floor is likely shellac or varnish. 

If you have a newer home, your floor is likely not shellac or varnish as these finishes are now rarely used.

If you do have shellac or varnish finish, your floor will need a full sanding before a new finish is put on.

If your floor was installed or serviced after the mid 1960s, or the finish did not flake off your coin, you can test it for a wax finish.  Apply two drops of water in an inconspicuous spot.  Wait ten minutes.  After ten minutes, look to see if there are white spots under the water drops.  If there are, you're looking at a wax finish.  If you need to get rid of the white spots, just use a gentle steel wool pad dampened with wax.

If your finish is not shellac, varnish or wax, than it has a surface finish that needs to be maintained according to the manufacturer.

What Not to Expect from a Wood Floor Finish:

A perfectly smooth table-top finish.  Each piece of flooring sands according to its specific grain type, and it is almost impossible to get a complete 100% flat surface on a floor. 

A Dust-free finish.  If you are having your floor finished in your home, there will be dust, and some will fall onto the new finish.

A  monochromatic floor.  Trees are individuals, and so is the wood that is derived from them.  There will be grain and color variations that will depend on the type of flooring material selected.

A  floor that will not indent.  Even with a finish, oak flooring will succumb to indenting with the exposure to high heels.

A  floor without cracks between the boards, or within the parquet pieces.  Wood expands and contracts from the changes of moisture in the air.  This will cause the boards to move, and possibly allow for color

variations.

Floors are unlike furniture.   A wood floor may actually be comprised of 300 to 1000 different pieces.  A piece of furniture may only contain 1-10.  Furniture is made and finished in a factory under ideal conditions.  A  floor being finished is subject to the conditions of the house.  With your individual tastes, selections, sizes and home environment, together with the immense amount of individual unique pieces that are used in a wood floor, there is no denying that your finished wood floor will be a unique custom floor.