Types & Grades of Hardwood

An important decision is choosing the type and grade of hardwood. The market offers many different options and making the right choice relies on a variety of aspects. It is very important to consider the construction type, the species, the installation type when trying to decide on the type and grade of hardwood to use for a home or business. Also keep in mind if the hardwood is prefinished or unfinished, and basic style and color options to suit décor needs.

Construction Types

1. Solid

The basic thickness for solid hardwood is ¾”. For thin profile solid hardwood, 5/16″ is the standard.

The planks are sawn in one of three ways and this affects the stability, and the price of the hardwood.

• Flat or Plain Sawn: is the most frequently used cut; it contains more variations than others.
• Quarter Sawn: cuts a log into quarters before it cuts the strips of wood to make hardwood flooring boards.
• Rift Sawn: cuts a log at a different angle than quarter sawn before it cuts the wood into hardwood flooring boards.

Solid hardwood floor planks are made with a tongue and groove edge locking process. This makes it easy to join the planks together in order to make a strong joint. One side of the board has a groove and the other has a tongue.

Solid construction can be sanded and refinished a lot of times and can last for generations.

One disadvantage is that it cannot be installed below grade or over radiant heat. Furthermore, most experts recommend not installing it over a concrete subfloor. Also, solid hardwood tends to be pricier than engineered wood flooring.

2. Engineered

Engineered hardwood is made by gluing a real hardwood veneer to a core board made of either plywood or high density fiberboard. This construction method leads to engineered hardwood is being more dimensionally stable than solid hardwood. The adhesives used must meet safe emissions standards for indoor air quality, such as E1 or E0 class or be CARB-compliant.

Engineered hardwood has several advantages over solid hardwood:

• It is less expensive than solid hardwood.
• It can be installed on all grades, including below grade.
• It can be installed over radiant heat.
• It can be installed over a concrete subfloor.
• It can be floated.

The number of plies used to create the plywood core may differ anywhere from 2 to 10, and while a 3 ply board is not going to be as stable as say a 5 ply board would be. The more plies in the plywood, the higher the price.

In conclusion, a plywood core is less dimensionally stable than a high density fiberboard core.

There are three different ways of cutting the veneer for the engineered flooring that, along with thickness, has an impact on price. The three methods of cutting the veneer include:

• Dry solid-sawn: involves letting the wood dry out with a low humidity level to keep moisture from inside the wood cells intact; this is the most expensive type of engineered flooring; it looks and acts more like a solid.
• Rotary-peel: involves boiling the log for a certain amount of time at a certain temperature to prepare the wood; after the wood has been prepared, it is scraped from the log with a blade working from the outside in and then pressed flat.
• Sliced-peel: involves boiling the log for a secure amount of time at a certain temperature to prepare the wood; after the wood has been prepared, it is sliced from the end and then pressed in order to create a veneer.

There are a few noticeable differences in recoating and refinishing which, once understood, may help you make the decision the right decision for your hardwood floor. Each option will give you the same result: a stunning and long lasting hardwood floor.

When recoating a floor, you need to take the finish off of the floor and bring it down to its last known stain color. The next step is applying a new layer of stain as well as finish. Use recoating if you’d like to update the look of your floor or make minor repairs. Removing scratches, filling gaps, or patching a hardwood floor can be reasons for recoating a hardwood floor. This process will also restore the shine of the hardwood floor and remove any discolorations.

Recoating is a clear-cut method which involves a thorough cleaning and light sanding of the floor that has the purpose of removing the previous finish. After you’ve finished sanding, another thorough cleaning will prevent bits of sawdust and dirt in the new stain and finish.

On the other hand, refinishing can include a bit more work. Some homeowners wish to have their floors professionally refinished rather than to do it themselves. Refinishing involves the same thorough cleaning process, but when it comes to sanding, the floor is prepped with a more intense sanding process. The goal is to get the wood down to fresh unstained wood in order to apply new stain and finish.

Remember that you best leave to a professional the sanding and refinishing an engineered wood floor with a veneer thickness of 2mm to 2.5mm.

3. Acrylic Impregnated Floors

Those type of floors have acrylic compounds injected directly into the wood. This way it results a stronger, harder, more durable wood.

These are mostly seen in commercial settings, this kind of floor may do well in a busy home with lots of traffic and can also handle more moisture than the standard hardwood floor.

Reclaimed & Recycled

These wood floors are unique in that they have been made from reclaimed wood. The wood may have been reclaimed from sunken boats, from logs salvaged from lakes and rivers or from old buildings and reprocessed.

This type of flooring is good for those who want to be green and can be either of solid or engineered construction type.

Grades

The Janka Hardness Scale is an important aspect of choosing the right wood flooring. This classification determines the durability of a particular type of wood over another.

A certain level of hardness may make a more charming choice, depending on the room where the flooring will be installed. The higher the number on the scale, the harder and more scratch resistant a wood is. The harder a wood is, the more difficult it becomes to saw or run through a mill. The great news is that this does not impact the price for flooring.

Common Grading Names

These are commonly seen grades for prefinished hardwood products:

• Clear Grade: is the best grade of hardwood flooring due to few color variations, board lengths are not widely varied; furthermore, there are little to no visible knots or pinholes.
• Select and Better: grade is slightly lower than the clear, still presenting uniform color and little to no knots and pinholes.
• #1 Common: presents with more color variation, shorter board length with greater length variation, and an increased chance of visible knots and pinholes.
• #2 Common: shows natural character, with darker and lighter boards, shorter board length, with an increase in visible knots and pinholes.
• Cabin Grade – is for those who are looking for a rough-hewn look in hardwood flooring; allowed checking, unfilled knot holes and worm holes, no splits, no loose knotholes.
• Shorts: has the most visible character with many knots, pinholes, and color variations present.

For unfinished hardwood products, these are typically seen grades:

• Clear Grade: is the best of hardwood flooring due to the fact there are a few color variations, board lengths are not widely varied, and there are little to no visible knots or pinholes.
• Select and Better: is slightly lower than the clear, still presenting uniform color and little to no knots and pinholes.
• Country or Exclusive Grades: presents with more color variation, shorter board length with greater length variation, and an increased chance of visible knots and pinholes.
• Traditional, Antique, Character Grades: show natural character, with darker and lighter boards, shorter board length, with an increase in visible knots and pinholes.
• Tavern or Cabin Grade: has the most visible character with many knots, pinholes, and color variations present.

Some sellers combine grades. For example, a floor may be sold as #1 common and better, meaning it is a combination of #1 common, select and better and clear grades. In this case, you will want to find out from the seller what proportion of each grade is.

Prefinished versus Site Finished

Prefinished boards are finished at the manufacturer by using a few coats of aluminum oxide (the second hardest substance in the world, after the diamond). Special equipment creates a durable surface for people to walk on, drying the finish almost instantly. Even though these are more expensive than unfinished floors, but can be installed in the home without having to worry about sanding and finishing.

Site finished flooring is unfinished hardwood installed on the site and then finished. These boards cannot use aluminum oxide since by the time the finish dries the aluminum oxide particles will sink to the bottom, in conclusion this is not providing a hardened surface for people to walk on.

Surface Texture Types

A few different surface textures are available in order to help customers to get the look they want.

• Smooth: refers to traditional milled boards.
• Hand Scraped: refers to boards that are distressed by hand.
• Distressed: refers to boards that are distressed by machine.
• Antique: refers to the boards with the appearance of extreme age.
• Wire brushed: The wire brush texture consists of a wire brush run over wood flooring, creating a rough, hard surface. The wire brush gets rid of the soft wood on the surface, making the floor more durable, less slippery, and easier to maintain.

Species

Traditionally, hardwood represents wealth, taste and style, with each grain pattern and texture bringing a unique masterpiece of natural splendor to the indoors.

Common woods are often dyed or printed to resemble more exotic woods, which means you can often get an expensive look at a fraction of the cost.

There are many distinct species available to use for hardwood flooring. Picking the right species is important as each species has different characteristics, colors and grain patterns.

Domestics

The following species are some of the more popular domestically grown and processed: White Ash, Beech, Birch, Black Cherry (aka American Cherry), Hickory-Pecan, Sugar Maple, Mesquite, Red Oak, White Oak, Pine, and American Black Walnut.

Exotics/Imports

The following species are some of the more popular exotics, imported from other countries: Bamboo, Brazilian Cherry, Bubinga, Cork, Cumaru, Spotted Gum, Sydney Blue Gum, Iroko, Jarrah, Mahogany, Brazilian Maple, Merbau, Tasmanian Oak, Padauk, Purpleheart, Brazilian Teak, Thai Burmese Teak, Brazilian Walnut, and Wenge.

For more information, go to our species page.

Installation Types

Hardwood can be divided into installation classes and you might want to select your hardwood by using this classification:

• Nail/Staple down: nails used to attach the wood to the subflooring and staple down uses staples to attach the wood. Staple down is simpler than nail down. Those two methods are not suggested for novice installers.
• Glue down: if the flooring is an engineered hardwood, it can be glued to the subflooring with a strong adhesive. This method is rarely used on solid hardwood floors (except thin profile solids).
• Float: is available in two options and it is made for an easier do-it-yourself installation. These floors are not attached to the subfloor and can be installed over just about any surface.
  • Glue-Seam: use an adhesive to glue the pieces together.
  • Glueless-Click: floors snap together and require no glue.