Lumber Information

product_lumberWhat is a stud?
A stud is a vertical framing member used to construct walls. It can be either a wood or metal vertical wall member to which exterior or interior covering material may be attached. It can be either load bearing or non-load bearing.

What does kiln dried (KD) mean?
KD lumber refers to lumber that has been seasoned in a kiln to a calculated moisture content reducing shrinkage, twisting, splitting and strengthening the finished product.

What is green lumber?
Green lumber is lumber that has not gone through a kiln dry (KD) process. It will vary in moisture content and has not generally been seasoned or air dried.

When is green lumber used instead of KD?
Regional market conditions and building trade preferences dictate local availability of dry or green products. In the dry Arizona climate, KD is what you would typically use. However, green lumber is used in supply of dimensional stock of 2×8 and wider widths, which has fewer propensities to twist because of the added thickness over 2×4 and 2×6. A builder may prefer green lumber for certain building applications or as specified by the architect.

What is plywood?
Plywood is thin sheets of wood made of three or more layers joined together with glue, and usually laid with the grain of adjoining plies at right angles. The layering or cross lamination of the plys is vital as it gives the plywood superior strength and stiffness. The cross layering also minimizes expansion, contraction and eliminates splitting.Almost always an odd number of plies are used to provide balanced construction. Plywood can be used for roof sheeting, sub-flooring, flooring, wall sheering, bracing, etc.

What is OSB(Oriented Strand Board)?
OSB is made in the basically the exact same fashion as plywood. Instead of using large sheets of solid wood veneer, thousands of 3 and 4 inch long strands of solid wood are combined to make each sheet of OSB. Each strand of wood is completely coated with high performance resin glue. It is a structural engineered wood product that maximizes our natural resources and has superior high strength characteristics. It can also be used for roof sheeting, sub-flooring, flooring, wall sheering, bracing, etc.

What is the difference between OSB and plywood?
In many ways plywood and OSB are virtually identical. Possibly the most important thing to realize is that when each product is manufactured according to strict guidelines and standards, they both exhibit superior strength and long term performance properties. You can count on both plywood and OSB for strength and stability as long as it is installed correctly. Builders tend to use CC plywood in exposed or visible areas as opposed to OSB because it has a smooth finished surface for painting. Typically either product can be used for the same sheeting applications. It is up to customer on preference and price.

What is a timber?
Timbers are five inches by five inches or larger and come in nominal widths of equal size or not more than two inches greater than the thickness (i.e., 6×6, 6×8, etc.). Douglas Fir timbers are best known for their tough fiber, dense grain structure and strength. They are valued for their rustic beauty and excellent “Heavy Timber” fire ratings in the model building codes. Timbers are shipped unseasoned and may be specified rough cut or smooth surfaced four sides (S4S). Timbers are usually used for structural support of floors, roofs, patios, door headers, etc. They are also used for aesthetics without serving any structural purpose.

What is a glulam (Glu Laminated Beam)?
Glulam is a stress-rated engineered wood product comprised of wood laminations, or “lams,” that are bonded together with strong, waterproof adhesives. Glulam components can be a variety of species, and individual “lams” are typically two inches or less in thickness. Glulams, like timbers, are also used for structural support of floors, roofs, patios, headers, etc. However, glulams are typically engineered and designed to carry more weight than timbers over longer spans.

When would you use a timber vs a glulam?
There is a rating code for timbers versus glulams. Beyond this, it is personal preference, price, and/or the appearance you are seeking.

What is free of heart center?
The heart center is the core in the center of the log or timber. Free of heart center (FOHC) is a special order item in which the mills eliminate the heart center when the timber is being cut. This generally results in a product with less twisting, splitting, and increased aesthetics, but it also a more expensive item than the commonly used non-FOHC.

What is S4S?
S4S (Surfaced Four Sides) refers to a piece of lumber or a timber that has smooth surface on all four sides. This is how lumber come from the mill. It does not need to be requested specifically nor does it demand a higher price.

What is rough sawn?
Rough sawn refers to the texture of the surface of lumber. Lumber that is rough sawn is rough to the touch and has a rustic look to it. It can vary slightly in overall dimensions and is generally more expensive than S4S because lumber comes from the mill S4S and then has to be resurfaced by machine, chainsaw or by hand to become rough sawn.

What is the formula for calculating how many board feet there are in a piece of lumber?
Most of the time, the end user does not have converse in terms of board footage. Usually, a homeowner or contractor will talk in terms of pieces, eaches, or lineal feet. However, another measurement used by suppliers and mills is board foot. A form of wood measurement, where one board foot equals the volume of a board 1 inch thick, 12 inches wide, and 12 inches long. A board foot is equal to 144 cubic inches of wood.

FORMULA: (Thickness x Width x Length) / 144 = Board Feet

A piece of wood measuring 12 inches square and an inch thick is equal to one board foot.
A piece of lumber 1/2″ thick and 12 inches wide and 24 inches long is equal to one board foot.
A piece of lumber 1″ thick and 6 inches wide and 24 inches long is equal to one board foot.

What are the different structural ratings for lumber—stud, standard, #2, etc.?
For dimension lumber, the grade indicates the fiber strength and stiffness of the lumber, which will determine where and how it can be used in the structure. Because knots affect strength and stiffness, their size and location are a primary concern.

Stud Grade is the most common grade used to build the framework of houses. Very little twist is allowed, although you can have wane and large knots. Stud grade is typically used for lengths ten feet and shorter.

Standard and Better has the same grade rating as Stud Grade but generally less wane, fewer knots with even less twisting allowance. Because of these factors it generally runs more expensive than Stud Grade, but it can be used in the same length and application as Stud Grade and in lengths greater than ten feet.

#2 and Better usually allow for smaller-sized knots and a minimum of wane and splits. It can be used in the same application as Stud Grade or Standard and Better. It is generally more expensive but many builders prefer it because of the range of application and less twisting and fall down.

#1 and Better consists of small, sound and tight knots, only inches of splits, and practically zero wane. It is usually used where framing will be exposed for aesthetics. This is generally a special order material because of it’s higher costs and limited request.

Stress Rated Material is machine rated and is specified by an architects or engineers for structural purposes to carry heavier loads or stress related loads such as would occur in floor and roof truss construction. It can be used in all the applications of Stud, Standard and Better and #2 and Better grades because it has little wane, fewer small tight knots and minimal twisting.

What is T&G?
T&G (Tongue & Groove) refers to a joint in which a protrusion (tongue) that runs along the edge of a board fits into a matching groove that runs along the edge of another board.

Boards or plywood shaped with a tongue on one edge and a groove on the other allows them to be fitted together without gaps. It is common feature for products being used on floors, sub-floors, ceilings, or siding.

What is treated/pressure treated lumber?
Treated or pressure treated lumber refers to lumber that is treated in such a way that a chemical sealer is forced into the pores of the wood in order lengthen its life expectancy for outside use or in ground applications such as the bottom plate of an exterior wall.

What is fascia?
Fascia is the wood materially that runs horizontally across the ends of the roof rafters ends, creating the “edge” of the roof. It is either combed or S1S2E.

What is combed fascia?
Combed fascia is fascia that is textured on all four sides. It typically shows as deep grooves looking like a comb has been dragged across the surface.

What does S1S2E stand for?
S1S2E stands for smooth surface on one side (face) and two edges, and rough on one side (face). .

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