Wooden Flooring Grain
When buying a hardwood floor you may be bombarded by all sorts of terms and phrases related to the appearance of the wood, known as the ‘grading rules’. Every species of wood has its own grading rules so make sure you ask your hardwood flooring company to provide you with the grading rules for the species of wood you are considering. At Gäte we work mainly with oak and here are our three grades:
Contains all the variations in coloration produced by the contrasting differences of heartwood and sapwood. Also included are minimal character marks, such as small knots, worm holes, and mineral streaks, as well as slightly open characters. The combination creates a floor where the light sapwood and dark heartwood are combined with small characters and other small color interruptions.
A flooring product characterized by prominent color variation that also contains prominent characters (with size limits) such as knots, open checks, worm holes, along with machining and drying variations. No. 1 Common is a tasteful floor where prominent variation is expected.
Contains sound natural and manufacturing variations including knot holes, open worm holes, and other open characters along with prominent color variations. Manufacturing variations include drying characters and machining irregularities. No. 2 Common is most desirable for applications where numerous notable character marks and prominent color contrast is desired.
Cuts of Wood
There are three well-known cuts from which flooring is made. The most popular is plainsawn, also known as flatsawn. Next we have riftsawn and quartersawn, which are different, but often sold together as rift and quartersawn (R&Q). A new trend is livesawn. It is a mix of R&Q and plainsawn, and to fully understand livesawn, it is important to have an understanding of plainsawn and R&Q.Hardwood flooring, like everything in interior design, has different stages of style and fashion changes. Plainsawn is the most common cut today, but prior to the early 1900s, quartersawn was all the rage due to its fashion and functionality. However, plainsawn developed and could be sawn more efficiently than quartersawn flooring, and it became commonplace. At that time, logs were quartersawn in a manner that produced 100 percent quartered lumber, which was very wasteful. Today’s R&Q is cut to produce minimal waste, but its overall production takes longer than plainsawn products.
Hardwood Flooring Cuts Defined
There are four ways that wood flooring can be cut from the tree; the cut used affects appearance and performance.It is easy to tell the difference between a plainsawn board, a riftsawn board and a quartersawn board.
The end grain of a plainsawn board has annual growth rings between 0 and 35 degrees. The face of the board has what is referred to as a “cathedral” grain pattern. Most old homes built in the early and mid-1900s had 2- to 3-inch plainsawn red oak, and when people think of oak floors, this is what they picture.
When the log is cut into quarters to make quartersawn boards, the annual growth rings are at 90 degrees to the surface. White Oak is especially popular in quartersawn because of the vibrant ray flecks along with the tight wavy grain pattern create a really cool and elegant look. The fleck is caused by the medullary rays, which are the life veins of the tree. The medullary rays are perpendicular to the annual growth rings and therefore parallel to the surface of the quartersawn board. These rays are very pronounced in the white oak and it creates this great figure.
This cut has annual growth rings angled around 45 degrees, and the grain pattern on the surface is very lineal. It’s important to note where the riftsawn boards come from in the log. When a log is quartered, it is then cut from the center face and works its way out. The boards that come from the outside edges have 45 degree annual growth rings. This comes from the smaller part of the quartered wedge. If you picture this, you can see why it is hard to get wide-plank rift only!
With this in-depth understanding of the difference between plainsawn, riftsawn and quartersawn, we can discuss livesawn, which is a mixture of these three cuts. Livesawn is cut straight through the log. You can see how the growth rings work their way out from parallel to the surface in the center to perpendicular to the surface on the edges. As you can imagine, the drying process requires extra attention due to this variety. However, it does create a very stable floor because it results in a high percentage of R&Q boards. Many people find wide-plank livesawn a spectacular look because it allows for more of the quartersawn and fleck in each board. The wider the plank, the more the natural beauty and larger knots can be represented in the floor. The end result is a unique floor that incorporates all the natural characteristics of the tree and wastes little in the process.
Hopefully this helps you understand the difference between the different “sawns” available and how they will act when installed in a home. Each hardwood flooring board has a life story, from its life growing in the forest through the sawmill and manufacturing process. No two boards will ever be the same, and the feeling you get from a quality hardwood floor cannot be replicated. This is why so many of us choose to work with wood floors for a living, and this the beauty of hardwood flooring.
When Moisture Comes & Goes
As we all know, wood is hygroscopic, meaning it shrinks or swells depending on the moisture levels. Below you can see the directions of expansion and contraction in the different types of cuts as they gain or lose moisture. Because of the direction of the growth rings, plainsawn boards change in dimension across their width, and the wider the board, the more the potential for dimensional change. Quartersawn and riftsawn boards, on other hand, change in thickness.
Here are our tips to make sure you get the flooring you expect:
- Don’t make your choice of flooring from a small sample, as these can be misleading.
- Ask your supplier to furnish you with the grading rules for their products.
- Visit your hardwood flooring supplier’s showroom to see larger areas of the floor concerned.
- Ask to see (pictures of) installations using the timber you’re interested in
- Finally, remember wood is a natural material and there will be variation from batch to batch. This is part of its beauty.