Wood Beams and Timbers: Grades
- #2 structural is the base of our grading system. It is primarily concerned with structural quality and may have some wane, checking and other defects that don’t effect structural quality.
- Choice is our own grade which is a #2 high-graded for appearance purposes.
- #3 has defects such as excessive checking, twist or rot that are not allowed in the #2 but are still useful in some applications.
- Green beams are cut from green timber which has a high moisture content.
- Dry or dead standing beams are cut from dead standing timber. They have a much lower moisture content and therefore are more stable.
*Because we hand cut our logs, and don’t use the conventional high-volume logging machinery, we are able to deliver these longer logs.
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Wood Beams Stability
When we talk about stability we are referring to how much a beam will shrink, twist, check and move as it acclimates to the environment it is in. All movement in wood takes place while the wood is drying out or picking up moisture. There are only two sources of beams that can be guaranteed not to move and that is glue lams and recycled — both of which may force you to sacrifice the price advantage and/or the appearance you are looking for. For this reason we make as many beams as possible, where stability is of concern, from dead standing Fir & Larch which is already partially dry and therefore more stable than green cut beams.
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Rough Lumber Specs
Movement in Wood
When wood dries out it shrinks. When it picks up moisture it expands. Consequently, in an exterior application in most climates wood will shrink and expand with the season changes.
In an interior application, once it acclimates, wood moves very little due to a more constant humidity. Where the product is being used in your project and your own personal taste is what determines how critical it is to try to control that movement. In many instances the natural movement in wood is irrelevant.
Rough Lumber Moisture Content
In applications where stability is crucial moisture content is very important. For interior applications 6% MC is ideal. In semi-dry climates 12% MC is ideal for exterior. In certain applications such as siding, proper installation is very important because of the continual movement of the wood. At RBM we can help you know what moisture content is ideal for your application and give you installation tips. In some cases we will either air dry or kiln dry products where lower moisture is necessary. Other times, when available, we will try to cut from dead standing timber because of certain advantages.
RBM Rough Lumber Grades
- #2&Better The baseline grade for our rough lumber is a #2&better which is primarily concerned with structural quality. It may have defects such as wane, checks, splits, stain, etc. within the limits of the grade. To some these characteristics enhance the rustic appearance of the product.
- Choice Choice is our own grade which is basically a #2 that has been high-graded for appearance purposes. It will be free of wane, no heart checks with pitch and various other defects are limited depending on the product.
- Select In some products we can supply a select grade which has very limited knot content.
- #3 This grade has defects that are not allowed in a #2 such as excessive checking, wane, rot or warp but it is still useful in some applications. Such as fencing and sheeting.
Rough Lumber Dimensions
At RBM we cut all our rough full dimension which means a 2×4 is a full 2″ by a full 4″ not 1 1/2″x 3 1/2″. This means our 2×6 has more wood in it than a surfaced 2×8. But you can special-order pretty much any dimension you want from ¼ inch thick up to 30 inches or wider depending on grade and species.
We try to inventory as much of the more commonly requested products as possible such as 2×4 through 2×12 in rough green and in dry exterior trim stock, as well as various specialty products like 5/4 trim for different siding products and commonly used 1” boards. 5/4 is a dimensional term… that is, it’s really a full inch and a quater thick. The width is dimensional… Our 5/4×4-inch is cut at a full 4-inches wide and then shrinks slightly as it dries.
Depending on the product we can cut up to 32 feet long. We literally have thousands of different products in stock and can cut almost anything.
Because there are so many uses for rough lumber with such a varied desire for appearance we at RBM don’t assume anything. We will ask as many questions as necessary to be sure your product both works and satisfies your taste for appearance.
Not all products come in all grades and all species
but we can usually find a product that will fit your needs.
If not we may know where you can find it.
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