I am a tree lover. It’s as simple as that. Not only does my livelihood rely on trees, but they are also incredibly multifunctional and literally help support life on Earth as we know it. If illegal logging and even poor forest management don’t piss you off, they should! First, trees are beautiful, both evergreens (conifers) and hardwood (deciduous). For those who slept through science class in high school, coniferous trees bear cones and have needles or scales that do not fall off in the winter and bear seeds. Deciduous trees have leaves they lose in the winter; they bear fruit or nuts.
All trees provide shade and cool the earth while absorbing carbon dioxide and emitting oxygen. You can do a straightforward experiment by simply standing in full sunlight and taking the temperature of the space, then standing under a tree and taking the temperature. It’s amazing and so simple. Now add the myriad benefits like food in the form of edible fruits, nuts and seeds, not just for us but so many forms of life. The trees keep giving: They are integral in making wine, spirits, root beer, beer, tanning leather, medicine and building materials. From railroad ties to fine furniture, ships to musical instruments, try to imagine a world without trees. The oldest construction on Earth used wood for its beauty, strength, workability and longevity.
In this article I will focus on the facets of timber pertaining to our industry: Workability, finish properties and any issues particular to a given species. We will focus on some of the most common indigenous wood species used in construction, particularly flooring and related trades: oak, maple, cherry, walnut, hickory/pecan, ash and birch. In a future article we can address exotic species commonly used for flooring. Note that all species mentioned are in good supply and have excellent reforestation over time—with the exception of Eastern ash, which is under stress from emerald ash borer beetles, and white oak, which isn’t regenerating at rates fast enough to replace current use, particularly for barrel staves.
This prefinished red oak was sanded to raw wood, then stained medium brown and coated with Bona waterborne finish. (Floor by Cody Johnstone)
Northern red oak
Quercus rubra | Janka: 1290
The tree(s):
Forty-four species of oak grow in North America. Northern red oak, or Quercus rubra, grows in uplands, well-drained slopes and riverbanks in Eastern North America.
Wood flooring advice:
Northern red oak is a heavy, hard, strong, coarse-grained timber that shrinks as it dries. The heartwood is pale or reddish brown, and the sapwood is darker. It is used for all interior construction, furniture, flooring and millwork types. It is easy to turn and mill and stains and sands quite well. It holds fasteners well.
Red oak will take stain well, but there are methods to ensure a deep, rich color. Water-popping the floor will give you a more profound, uniform color, and products are now available from the finish companies expressly to remove the “pink” cast of the wood without bleaching it. As noted earlier, the spring and summer grain is softer, so the cut of the wood is a factor in how it performs: Rift and quartered wood is more uniform in hardness than plainsawn or livesawn. Also, rift and quartered wood is more stable in terms of the seasonal movement of the wood.
Random fact: Red oak is native to North America, but some saplings were planted in France in the 1700s. It can now be found sprinkled throughout Europe.
Top, first-grade maple coated with Loba Hybrid and then Duo 2K (floor by Jaime Espinoza). Above, second-and-better maple with a subfloor system by Robbins Sports Surfaces and Bona Super Sport water-based finish (floor by Floors Incorporated).Northern maple
Acer saccharum | Janka: 1450
The tree(s):
Maple grows in well-drained soils, especially in northern climates. It can be found in stands with beech, yellow birch, hemlock and black cherry. Maple is used in furniture manufacturing and is prized for figured veneers such as bird’s-eye, tiger and curly.
Wood flooring advice:
It is used extensively in sports floors as well as residential applications. Due to its hardness, maple is more challenging to work with and shape.
Because of its light color, lack of a busy grain pattern and hardness, it is more difficult to sand and stain. This is a perfect example of starting the sanding process with the finest paper that will get the job done. If you don’t put in deep scratches, you won’t have to remove them. The lack of visible grain in the wood means that any scratches are much more visible than they would be on an oak floor.
Job-site staining takes practice and patience. To avoid a blotchy appearance, water-popping before staining will help, as will applying a wood conditioner (available at any paint store and at some distributors). That said, care during the sanding process is most important. You may have to “over-sand” to make sure there are no scratches that will appear only when the stain is applied … hence, water popping to get good stain penetration. Also, know that some stains or colored oil finishes will have a much more consistent appearance on maple than others, so experiment to find a product that works best.
Random fact: Maple sap is tapped without killing the tree to make maple syrup.
White oak two drastically different ways: At left, its natural color coated with Bona Traffic HD (floor by Jonathan Gramajo). At right, this 3-inch white oak is Muscanell Millwork’s “Casa Grade” with two coats of Rubio Fume and two coats of Procoat Unocoat Country White (floor by Mike Wong).
White oak
Quercus alba | Janka: 1360
The tree(s):
White oak grows on low-lying ground by rivers and in rich soils on higher ground if the earth is not too damp. It sometimes forms forests by itself.
Wood flooring advice:
The wood is heavier and has a closer grain than red oak, making it somewhat more durable. White oak is easy to work with and shape, but it is harder than red oak, and finer abrasives will tend to burnish the wood faster than they will with red oak.
As the name implies, white oak has a different color than red oak, so keep that in mind when choosing stain colors and finishes. Lower grades of white oak can also have more sapwood, with a blonder appearance that does not take stain the same color as the rest of the floor, so some pros will make a sap stain to color those areas of the floor before staining the entire floor.
Finishing can be problematic with white oak, as the tannins can cause discoloration, streaking and green to yellowish colors if not appropriately treated. Most good sealers will block the tannins in oak and prevent that discoloration. The tannins in white oak can also be used to an advantage, as they react in interesting ways with different products (pros use everything from certain “reactive” finishes to a solution of vinegar and steel wool) to create various color effects (such as in the photo at above right).
At left, No. 1 common cherry coated with Bona Traffic (floor by Austin Macdonough). At right, This 7-inch select cherry had a final sanding of 100 with a Hydrasand, then was popped with straight denatured alcohol before being stained with a mix of DuraSeal Jacobean and English walnut stain and coated with poly (floor by Lorie Davidson).
American cherry
Prunus serotina | Janka: 950
The tree(s):
Cherry trees grow in Appalachian forests and eastern North America on dry, sandy, gravel and damp soils. They are one of the most valuable timbers for making furniture and veneers.
Wood flooring advice:
Cherry is relatively soft, so care must be taken when using it in flooring. It dents and dings easily, so it isn’t a great choice for high-traffic areas, but it can be stunning in the right applications. It is easy to work and shape. It sands well but scratches easily. As always, but especially with cherry, start with the finest grit possible to flatten the floor.
Cherry is extremely photosensitive and darkens quickly when exposed to light. During installation, even a few boards left in a sunny spot will quickly turn darker than the rest of the floor. When selling a cherry floor, be sure the customer sees samples of both what a new cherry floor looks like and what an aged floor looks like.
Cherry takes stain well but, like maple, can turn out blotchy, so the earlier advice about water-popping, using a wood conditioner and using the right stain and/or finish also goes for cherry.
At left, this 8-inch engineered character-grade walnut in the process of being coated with Bona DriFast sealer shows how coatings reveal the depth of the wood (floor by Michael Settlemyre). At right, common-grade walnut flooring coated with Pallmann Pall-X Color Sealer and Pall-X Power in Satin (floor by Justin Braun).
Black walnut
Juglans nigra | Janka: 1010
The tree(s):
American black walnut grows mainly in lowlands and hillside zones from Southern Ontario, west to southeast South Dakota, south to Georgia and Northern Florida, and southwest to Central Texas. It is used extensively in manufacturing furniture, veneers and rifle stocks.
Wood flooring advice:
It presents with striking light sapwood if it isn’t steamed to give it a more uniform color. The lower the grade of flooring, the more sapwood it will have. More than one wood flooring pro has been surprised to sand a prefinished walnut floor and discover there is actually a lot of blond sapwood in the floor instead of the consistent dark brown walnut appearance it had while prefinished. Just as with some white oak, some pros will use a sap stain before staining the entire floor to disguise the blond sapwood and make a consistent color across the floor.
Walnut is not as photosensitive as cherry, but it does change color when exposed to light. Unlike most species, it gets lighter with light exposure instead of darker. As with cherry, be sure to show customers samples of a new floor and an aged floor.
Walnut is easy to work with and shape but, like cherry, can be difficult to sand and finish due to its relative softness. At a Janka hardness of 1010, it is harder than cherry, but still take care regarding where it is installed, avoiding high-traffic conditions.
Random fact: American black walnut trees do not produce the walnuts we usually think of and eat—those come from English walnut trees, whose branches are grafted to American walnut trees to produce the nuts we use for food.
At left, this solid select-grade hickory was coated with Bona NaturalSeal and Bona Mega One (floor by JACE Hardwood Flooring). At right, second-grade hickory with Espresso stain and Berger-Seidle Greenstar semi-gloss finish (floor by Doug LeClair).
Hickory/pecan
Carya illinoinensis | Janka: 1820
The tree(s):
Hickory and pecan are not the same wood, but they are so similar that they are usually sold together as “hickory-pecan.” They produce different nuts, both prized as food.
Wood flooring advice:
Due to its hardness—substantially harder than the oaks—hickory is more challenging to work with and shape than oak. Like maple, do not put unnecessary deep scratches in it when sanding, as they are time-consuming to remove.
Because hickory is hard and dense, especially around knots, it can be challenging to stain. An issue we run into is the fact that in a factory-finish process, the color doesn’t penetrate the wood fiber. Color is rolled or sprayed on, and it sits on top. So, matching a factory-finished sample on a job-site-finished hickory is virtually impossible. There is a technique called glazing, where color is added to the finish and applied in multiple thin coats to get the desired color. This is an advanced skill set, so practice before attempting it in the field. Adding to the difficulty in staining hickory is the wood’s natural character, which is noted in its dark brown stripes and color differences.
At left, Muscanell Millwork’s select “Hacienda Grade” of ash coated with Berger-Seidle Natural White 2K (floor by Mike Wong). At right, WoodCo unselected 5/8-by-5-inch ash in 10-foot lengths was stained with DuraSeal Medium Brown and coated with two coats of Berger-Seidle Exobloc and two coats of CeramicStar Satin (floor by Higher Standard Hardwood Flooring LLC).
White Ash
Fraxinus americana | Janka ball: 1320
The tree(s):
Fraxinus is a genus of plants in the olive and lilac family, Oleaceae, and comprises 45–65 species of usually medium-to-large trees, most deciduous trees. However, some subtropical species are evergreen trees. Ash is valued for producing tool handles, hurling sticks, baseball bats, oars, furniture, and in boat building and traditional crafts like woodturning.
Wood flooring advice:
It is easy to work and shape. The heartwood is light tan to dark brown, and the sapwood is cream white. It is similar to white oak but has its own distinctive grain pattern that most wood flooring pros can spot easily. It sands much like oak, and like other species with similar grain, care must be taken to cut it flat on the first pass and not dish out the softer grain in subsequent sanding grits. It takes stain well.
Unfortunate fact: The emerald ash borer beetle is attacking ash trees in the Eastern U.S., but the wood is still readily available. Ash trees are common in Wisconsin, with estimates as high as 765 million trees in wooded areas and over 5 million in urban areas.
At left, common-grade red birch finished with Professional Coatings UnoCoat Natural (floor by Tony Horsman). At right, a select-and-better mix of heart and sap wood sourced and milled by Dan Antes; it was coated with DuraSeal Quick Dry Sealer: “Basically a gloss making the chatoyancy pop, topped with DuraClear Max semi-gloss to not dull down the brilliant figuring,” says pro Walter Bastian.
Birch
Betula spp. | Janka ball: 1260
The tree(s):
Birch is a thin-leaved deciduous hardwood tree with alders, hazels and hornbeams. It is closely related to the beech-oak family Fagaceae.
Wood flooring advice:
Birch is common in flooring and is sometimes used as sports flooring. Although it is commonly sold as “red birch” and “yellow birch,” they are not different trees, just different cuts of the same tree: sapwood becomes yellow birch and heartwood becomes red birch.
Birch is easy to work and shape. It sands and finishes nicely and takes stains well. Because it has a somewhat similar appearance to maple, care must be taken to not have visible sanding marks, as they will not be disguised by its smooth grain.
Random fact: For thousands of years, Native American hunters built stable, agile, durable and light canoes from birch bark, cedar, and spruce roots. Flipped over, they could even provide shelter. Native Americans also used the tree’s leaves, bark and buds to make medicine. Birch is used for joint pain, kidney stones, bladder stones, urinary tract infections and other conditions.
Important Rules of Thumb for All Species
White oak floor by Alex Oster
Before we go into specifics for each species, let’s start with the most common “rules of thumb” in working with wood flooring:
Get it flat, then remove scratches: Remember the bottom line in sanding: We put scratches in the wood to get the floor flat; the rest of our job is to remove those scratches before applying stain or finish. Common sense dictates that we minimize the initial scratch to make our job easier and faster. So, instead of starting with 24- or 36-grit paper, try the finest paper to get the job done and then go from there, remembering not to skip more than one grit in the sequence. The time it takes to try a 50- or 60-grit will be made up by not having to do three cuts. The milling of the wood and any issues like cupping or crowning will determine your grit progression.
Never use a dull blade: Workability is how easy or difficult each species is to cut, shape or sand. All the native species used in flooring are relatively easy to work, i.e., cut, shape, glue, nail, etc. The most dangerous thing when cutting wood is a dull blade! Use care while using table saws, including keeping the guards in place, proper eye protection, dust masks, push sticks and good lighting. We want to finish every installation with ten fingers! Remembering that wood dust is a carcinogen at worst or can cause COPD, sinusitis, and more is also crucial. So, use a certified dust mask to prevent issues down the line.
Keep the hardness in mind: Hardness is also important when selecting wood species for flooring. We reference the Janka test, which measures the force required to embed a .444 steel ball to half of its diameter into the wood and gives a reference number for comparison between species. Remember that species with pronounced spring and summer grain, like oak and ash, will have a pronounced difference between the grain pattern in hardness. The spring and summer grains are softer than the fall-to-winter dormancy grain. Northern red oak is the “norm” when referring to species hardness. In other words, hickory is harder than Northern red oak, and cherry is softer.
Know the dimensional stability: Species vary widely regarding how much they shrink and swell with changes in moisture content. You can look up dimensional stability rates in the Wood Handbook, although of course these rates can vary greatly depending on the width and cut of the flooring. Some species, such as hickory/pecan, are notorious for their dimensional instability. Remember, you always want to moisture-test and install the flooring at the midpoint of its expected equilibrium moisture content for each particular job site.
