Flooring Resources Guide

Unfinished or prefinished hardwood?
Most all types of wood flooring are available Unfinished. This allows you to be creative with any personal choices you may have pertaining to certain wood species and size of boards to be used. It also allows you to pick your own stain color and finish sheen.

Prefinished strip, plank or parquet floors are either factory finished or acrylic impregnated (Liquid acrylic and stain are impregnated throughout the pores of the wood) when manufactured. Prefinished floors can be purchased as solid 3/4" thick wood or as a engineered wood. Prefinished flooring may have up to 10 coats of finish applied at the factory and have a 25 year wear warranty.

What is the best finish for a wood floor?
There are many different manufacturers who make numerous types of wood finishes that are available on the market today each boasting that theirs is the best. This abundance can be overwhelming and confusing to someone who wants to purchase the best finish for their wood floor. Just reading the label doesn't help. Below I have written some of the characteristics of these finishes and their uses. Then it will be up to you to determine what would be the best finish for your application. Most finishes contain chemicals that may be harmful. I always recommend using a proper respirator when applying them.

Through the years many different finishes have been applied to flooring. They all have their advantages and disadvantages. The earlier finishes used were wax, shellac, varnish and lacquer. They are rarely used today as wood floor finishes because of the high maintenance involved and low durability. The more durable finishes such as oil-modified urethanes and water-based finishes are more widely applied to flooring today. The Newer “Alumide or Ceramic” finishes are extremely durable and often come with a 25 year finish warranty.

Shellac: With its great sealing capabilities was the finish to use prior to the 1950s but went out of style with the advent of newer finishes. Shellac now has regained a position as a floor finish and is used as both as a sealer coat under certain finishes or as a finish by itself over antique wide plank flooring. Shellac gives antique flooring a wonderful rich patina and is fast drying usually 1-2 hours between coats. It adheres well over other types of finishes. When dry it forms an excellent barrier to help protect the wood from humidity. Although it is not as durable as a top coat on floors as some of the newer finishes, shellac still has its place in line with long-time floor and furniture refinishers that want that original depth and color that only shellac can give you. Shellac is susceptible to water spotting (white discoloration) so it is not recommended for use on a kitchen or bathroom floor. Apply 3-4 coats (the more coats the deeper the color) with a 4-6 inch polyester-nylon bristle brush. Reduce the first coat with denatured alcohol 50/50 to allow deeper penetration into the wood. Allow 1-3 hours drying time between coats, lightly sanding between coats. After 24 hours apply a good quality paste wax with a high speed buffer to help protect the finish. The floor would then require periodic re-waxing once the sheen is worn off.

Oil and wax finish: is another older type finishing method where a penetrating oil sealer (available in various stain colors) is applied to the bare wood surface. This is allowed to dry for aprox 1-3 hours then a second or third coat is applied rubbing in between coats using a rotary buffer with 600 steel wool which removes any excess stain. After aprox. 24 hours drying, a coat of paste wax is applied and buffed with a high speed buffer. This method is more frequently used in commercial applications. It does require more maintenance by periodic waxing or rebuffing to bring the luster back. But it is more repairable than a urethane based finish.

Varnish: was the next progressive step for floor finishes. Made with natural resins of fossilized sap and natural oils like linseed and tung and later soybean and safflower. The development of synthetic resins led to phenolic-resin varnish a combination of phenol and formaldehyde with a natural oil. Varnish is harder than shellac so it makes touch up more difficult. Varnish is not as durable as some of the newer finishes on the market today. The common method of applying varnish is to apply three coats allowing each coat to dry overnight with light sanding and vacuuming between coats. To apply use a 4-6 inch pure China bristle brush.

Oil modified urethanes (polyurethane): One advantage of an oil-base urethane finish is its durability. The application is relatively easy. The coating has a thick looking appearance and gives oak flooring a honey color tone. It has great moisture resistance and is also one of the most scratch-resistant finishes available. It can be hard to touch up or recoat. Oil-based urethanes have a tendency to darken and or yellow with age. How much will depend on the quality of the urethane that is purchased. Oil-based urethanes are applied in much the same manner as in varnishes mentioned above.

Moisture Cured Urethane: The major difference between this urethane and other urethanes is that it contains Di-Isocyanate Methyl-Benzene. While most finishes dry through evaporation of the solvents leaving the resins on the floor, moisture cured urethane dries by pulling moisture from the air. This process along with the unique way it cross links makes moisture cured urethane one of the hardest finishes available. The disadvantages of moisture cured urethane are that it has a very unpleasant odor. A respirator is a must when applying because of its toxic fumes. It is also extremely difficult to apply.

UV-Cured Urethane: This finish is applied at the factory and must be cured with Ultra Violet lights. This is an extremely popular method with prefinished hardwood flooring manufacturers.

Water based finishes: are made up three different ways. 1. Acrylic (less durable), 2. A blend of acrylic and polyurethane (durable), 3. One hundred percent urethane (very durable). These finishes do have some advantages over the oil-based urethanes. Their drying time is much faster (one to two hours), there is little odor, and clean up is with soap and water. Most waterbase urethanes are a clear finish and frequently used over white and pastel colored stains. Their application can be difficult due to its quick drying. The method of applying water based finish is similar to that of any fast dry finish where it must be applied quicker in smaller sections to prevent lap marks. Personal opinion dictates whether or not it is a disadvantage that water based finishes do not produce the thick looking finish and amber color like the oil modified urethanes; and, also they are more expensive to purchase.

Alumide or Ceramic finishes: Contain particles of Aluminum oxide or Ceramic mixed with the finish and are the new factory applied finishes. These Finishes are extremely durable and long lasting. It is very important to remember that whichever type of finish you choose read the manufacturer's directions before using the product or call them. Most companies are glad to help with questions.

Relative Hardness chart for Wood Species
To the right is a Relative Hardness Chart of Selected Wood Flooring Species this helps determine the hardness of a particular wood species. These ratings were performed using the Janka Hardness Test, which measure the force needed to embed a .444 inch steel ball to half it's diameter in a piece of wood. The higher the number the harder the wood. Although this is one of the best methods to measure the ability of wood species to withstand indentations, it should be only used as a general guide when comparing various species of wood flooring. The region in which the wood is grown from and the particular botanical name from within the same wood specie may vary the rating.

Will my wood floor dent?
Hardwood floors as with all wood are comprised of basically soft wood fibers and millions of cell structures. The density of these wood fibers technically makes one wood harder than another. But all wood will dent if something heavy is dropped on it. The spike end of a high heel shoe can indent the surface of the wood as well, i.e. a 110 ten pound woman will exert 2000 pounds of pressure at the tip of the heel.

Plank Edge Styles
Hardwood floors come in either a square edge or a beveled edge, Today, most prefinished hardwood flooring manufacturers are calling their beveled edge "eased edge" because the tapered edge is dramatically reduced from the old deeply grooved edges. The new Micro beveled edges provides a smoother more uniform surface and eliminates some of the problems seen with some manufactures prefinished square edge flooring that has sharper edges (called overwood).

Square Edge
The edges of all boards meet squarely creating a surface that blends the floor together from board to board. The overall look of this floor gives a contemporary flair and formal feeling to the room.

Micro or Eased Edge
Each board edge is just slightly beveled. Some manufacturers add an eased edge to both the length of the planks as well as the end joints. Eased edges are used to help hide minor irregularities, such as uneven plank heights which is often called “overwood”. Eased edge is also called micro-beveled edge. These micro-beveled edges are factory finished and so small there is No need to worry about dust or dirt getting trapped in them.

Heavy or full Beveled Edge
These products have a very distinctive groove in them and shows off each plank. Beveled edge planks lend themselves to an informal and country decor. With the urethane finishes applied at the factory today the beveled edges are sealed completely making dirt and grit easy to be swept or vacuumed out of the grooves. Beveled edge floors help hide subfloor irregularities that could result in variations in board height, which is often called "overwood".

What should I know about subfloors?
Generally any flooring can be installed over a subfloor of plywood, or a solid 3/4" wood surface. I personally do not recommend wood flooring to be nailed or stapled into particle or fiber board.

If your subfloor is concrete or stone, your choices maybe limited. Excessive moisture that may be in concrete, or stone will be absorbed into the wood flooring installed on top of these surfaces. without using a vapor barrier wood flooring may buckle, and/or cup from the excess moisture. If a moisture reading of the concrete or stone is over 12% moisture content, I wouldn't recommend a wood floor of any type being used. If the moisture reading of the concrete is below 12%, the best choice of flooring in these instances would be either a floating floor with a foam pad and a 4-6 mil. plastic vapor barrier, or install a glued down engineered hardwood floor with a waterproof adhesive. If a 3/4" solid wood floor is desired, a raised system of 1x2 sleepers 12 - 16 inches apart would have to be constructed with a plywood platform on top. It is critical prior to the construction of sleepers to put a vapor barrier of 4 -6 mil polyethylene plastic down with all joints taped with duct tape.

Should wood flooring be acclimated?
Before any flooring is delivered make sure that the conditions are right. All concrete, masonry work, plastering or anything else that deals with moisture must be thoroughly dry. Normal living conditions should be maintained 7 days before any flooring is delivered, i.e. heating, air conditioning. When the flooring is delivered, store it only in the rooms where it will be installed. This is so the flooring can acclimate to the conditions in which it will be installed. Average acclimation time is generally one to two weeks. A moisture reading should be taken of the flooring and subfloor before installation to ensure the levels of both are within the range of relative humidity for your area. (Generally between 6-9%.)

Why does hardwood flooring expand and contract?
Hardwood flooring like all woods are considered "Hydroscopic", which means that they have the ability through their cell structure to absorb and release ambient moisture that's prevalent in it's environment. Hardwood flooring at the time of manufacturing is kiln dried from approximately 30% moisture content to between 6-12% moisture content. This figure of 6-12% moisture content represents the standard normal relative humidity level of between 45-55 percent that normally should be present within your home. If that home's standard, normal relative humidity changes, for any great length of time, a dimensional change may be seen in the size of each board.

For example: Flooring may in some colder parts of the country shrink in size during the heating season when the ambient air in the home becomes dry. The flooring itself then dries out, loosing moisture. This in turn can cause gaps between the boards. The size of these seams will be large or small depending on the amount of moisture loss. These gaps often close when the flooring regains it's lost moisture content during the summer months.

Flooring also can absorb more moisture than it was kiln dried down to and expand during the hot humid spring and summer months, which normally have higher humidity levels. Sometimes causing cupping in the floor boards

Can this expansion and contraction be controlled?
Yes, it can be controlled, if during the dry heating season you notice your floor boards starting to contract in size leaving gaps between floor boards introduce moisture into the area using a humidifier. Maintain the RH at 40-55% year round. I always recommend to purchase a small digital hygrometer available at your local hardware center. It will tell you what you RH is daily.

If during the hot humid summer months the flooring expands and starts to cup run either an air conditioner or a dehumidifier to remove excess moisture from the air. Remember that maintaining this 40-55% RH year round is not only beneficial for your flooring its also good for your own health, and comfort.