how lumber is cut

What is the Difference Between Gross Tally and Net Tally?

One of the most confounding measurements to understand if you haven’t been around the sawmill and lumber business for a long time is gross tally and net tally. What exactly is the difference between gross tally and net tally? And why is lumber sold both net tally and gross tally? How do you convert from gross tally to net tally? We’ll take you through the basics.

What is the Difference Between Gross Tally and Net Tally?

Gross tally, also sometimes called green tally, is the volume of wood in board feet delivered to the mill after it is cut. This lumber hasn’t been dried yet and has a high amount of moisture in it. When lumber dries, water is removed from the wood resulting in a smaller overall volume of wood. That smaller volume of wood is known as net tally.

Gross Tally >> the lumber volume measured before kiln drying.

Net Tally >> the lumber volume measured after kiln drying.

Why is Net Tally versus Gross Tally a Big Deal?Stacked up wood

It is necessary to understand whether a lumber quote or price is based on gross tally or net tally. The issue isn’t always whether the tally is net or gross, but how that number was determined. Find out whether the tally was measured after coming out of the kiln or whether the gross tally was used to calculate net. This will make a difference in the actual volume of lumber.

Also ask what shrinkage rate was used for your lumber. Each sawmill may use a different shrinkage rate to determine net tally – usually between 7% and 9%. In addition, how a company calculates it also slightly changes the resulting volume numbers. If a company uses 8% but multiplies by 1.08 that will return a different volume number than if they divide by 0.92.

How Should I Buy Lumber – Gross Tally or Net Tally?

Since hardwood lumber invoices are based on measured board footage, it is important to know if the price you are being quoted and paying is based on a gross tally or net tally. Sometimes it may seem a deal is too good to be true and it may be. Sometimes the reason for that unbelievable price is hiding in the tally.

Be sure you clarify if the transaction you are conducting is measured on gross measure or net measure. Know what your price is per the type of tally. If you are ordering lumber with additional remanufacturing, be sure to find out how that is accounted for in the overall volume you will receive. A straight line rip will cause the volume of lumber to shrink again.

Buying net tally can reduce confusion and will give you the tools to accurately determine the volume of lumber you are receiving. However, either tally method can be used IF you have answers to all of the variables that affect the overall volume.

Why Does Dried Wood Absorb Moisture?

Wood and Moisture: It’s All Biology

The hardwood lumber that you buy at the lumberyard began as a living tree. As a living tree, the trunk of the tree provided a way to transport water from the roots to the leaves. When the tree is cut down that water moving system is still present in that tree and much of that water is still in the lumber when it is first sawn.

Hardwood lumber just cut, referred to as green lumber, can have a moisture content of 40% or more! After hardwood lumber is sawn, it is typically air-dried to around 15% moisture content. Hardwood lumber will be continued to be dried in a kiln to a moisture content of 6-9%.

Wood is hygroscopic, which means just like a sponge the moisture content will change depending on the relative humidity of the surrounding air. When humidity increases, the wood absorbs moisture from the air causing the wood to expand. When the humidity decreases, the wood releases water into the air and the wood shrinks.

What Direction Does Wood Expand In?

When wood expands and contracts because of changes in moisture content, hardwood will move in a predictable way. Wood shrinks most in the direction of the annual growth rings (tangentially), and half as much across the rings (radially), and only slightly along the grain (longitudinally). or from the center of the tree to the outer edge).

Hardwood shrinks most in the direction of the annual growth rings (tangentially), about half as much across the growth rings (radially), and only slightly along the grain (longitudinally).

Flat-sawn boards will cup away from the heart of the tree. The shrinking will occur mostly in its width.
Rift-sawn boards will warp and shrink into a diamond or trapezoidal shape.
Quarter-sawn boards will shrink slightly in both length and width.

What Do I Do About Moisture and Wood Movement?

The solution to this problem is quite simple: don’t stop the wood from moving, but rather account for its movement. With a little bit of knowledge, you can predict the degree of wood movement, and take action to accommodate the movement.

Differences to Know When Designing With Quarter Sawn Hardwood

Quarter sawn hardwoods are beautiful and distinctive. The unique look of quarter sawn hardwoods lend itself to an array of design styles, from traditional to modern.

But, when designing with solid quarter sawn hardwoods, it is important to understand how the uniqueness of this wood comes with a limitation in product width.

Why Is Quarter Sawn Lumber Narrow?

In order to obtain the distinctive straight-grained appearance of quarter sawn lumber, logs must be sawn in a different way. The log is first cut in half and then into halves again. After being cut into quarters, each quarter section is placed on the mill in a position so that the annual rings are as close to 90 degrees (perpendicular) to the face of each board as possible when sawn.

By sawing the log in this way, quarter sawn lumber yields more waste and therefore the end result is narrower boards, in comparison to plain sawn lumber sawing methods.

Print       plain-sawn

 

Why is Quarter Sawn Hardwood More Expensive?

Quarter sawn hardwood can command a premium over plain sawn lumber. This is primarily due to a more limited availability of quarter sawn lumber – both because of the lower number of boards made from each log and combined with a much smaller number of suppliers producing this kind of lumber. This limited availability of quarter sawn lumber results in a premium price for this type of lumber.

Is Quarter Sawn Hardwood Worth It?

The principal benefit of the quarter-sawing technique is that all of the grain will be straight, resulting in a more dimensionally stable product. Quarter sawn lumber typically does not warp, twist, or cup. A narrow grain pattern is typically evident on the face of the board. Flecks are generally evident in quarter sawn red oak and white oak, but can also be seen in other species. Read more about quarter sawn wood.

Is Quarter Sawn Wood Still A Green Choice?

Many have asked whether the higher waste involved in making quarter sawn wood result in a product that is less environmentally friendly than traditional lumber. The answer is simple – quarter sawn wood is a sound environmental choice. (Read more on why solid wood is a great design choice for our environment.) Companies who produce quarter sawn lumber use the rest of the log in a variety of ways. Bark can be turned into mulch and wood chips supply paper companies, while sawdust is often used on-site to fuel drying kilns. No part of the log is left unused.

Tips for Buying Hardwood Lumber through a Distributor or Lumberyard

 

Are you planning your first visit to buy lumber? Once you’ve decided to go beyond buying lumber at a home center, there’s some major differences to be aware of when buying lumber at a lumberyard or distributor.

Lumberyards and distribution centers have come a long way, offering a wide variety of wood species, thicknesses, grades and machining options. Here are some pointers for how to buy lumber at a distributor or lumberyard.

 

 

THICKNESS

When buying hardwoods, you won’t see lumber thickness marked in inches, but instead the convention is to use a measurement in quarters. For example, a 1 inch thick board is typically written as 4/4.

One thing to keep in mind is that lumber is sawn and then dried so the board that started out 4/4 inches will be closer to 7/8” (.875 inches) – and that thickness is before any type of surfacing is done.


BOARD FOOT

A board foot is the unit of volume used to measure hardwoods. Since hardwoods are sold in a variety of lengths, widths and thicknesses, it is simpler to have a kind of measure that can account for all of those variables at once, like volume.

12” long x 12” wide x 1” thick = 144 cubic inches

Calculate a Board Foot
   special thanks to American Woodworker for this image.

Armed with a tape measure, calculator and this knowledge, you can tackle any board foot calculation on the spot. But what happens the day you leave the shop and forget your calculator? Use this woodworker rule of thumb:  4/4 board, 8 ft. Long and 6” Wide = 4 Board Feet


GRADE

For someone just beginning to purchase hardwood lumber, lumber grades can be overwhelming. Most lumber companies use the generally accepted grading rules set by the National Hardwood Lumber Association. Grades are based on the amount of usable clear material in a board. The highest grade boards are FAS and Select, followed by #1 Common and #2 Common. What grade you choose depends on your project. Some projects, such as tabletops and high quality furniture, may dictate the highest grade available. Many other projects are just as easily adapted to #1 Common (often referred to as cabinet grade) – kitchen cabinet doors, smaller projects and items where some character is acceptable.

For a full illustrated guide to the various grades:
http://www.ahec.org/hardwoods/pdfs/IllustratedGradingGuide.pdf

MILLING SERVICES

Rough lumber is rarely flat or straight. Milling your own can save you some money but it will take time, equipment and a strong back. It can be beneficial to look into what milling options your distributor can offer.

Most yards will offer the following milling services:

–       Rip one edge of a rough board straight (called SL/E, Straight-Line Edge)

–       Plane both faces lightly by taking approx. 1/16” off the surface (called Hit-and-Miss)

–       Plane both faces, leaving no little wood with rough cut marks, removing approx.. 1/8” of thickness (called S2S, Surfaced Two Sides)

–       Mill both faces and edges (called S4S, Surfaced Four Sides).

There are typically varying costs added to the price of rough lumber to cover the additional milling. Depending on your situation, these added costs may save you money in the long run through saved labor, faster lead times and a reduction in equipment needs.

What is the difference between Quarter Sawn, Rift Sawn and Plain Sawn Lumber?

When lumber is cut from logs, it is typically cut in one of three ways: quarter sawn, rift sawn or plain sawn. Each type of lumber is dependent on how the log is oriented and cut at the sawmill. The result is a particular orientation of the growth rings on the end grain of the board and is what defines the type of lumber.  The type of cut also determines the figure in a piece of wood and the wood’s mechanical properties.

Sound too confusing? This graphic will help…

PLAIN SAWN / FLAT SAWN
Most common, least expensive
Plain sawn, also commonly called flat sawn, is the most common lumber you will find. This is the most inexpensive way to manufacture logs into lumber. Plain sawn lumber is the most common type of cut. The annular rings are generally 30 degrees or less to the face of the board; this is often referred to as tangential grain. The resulting wood displays a cathedral pattern on the face of the board.  See pictures here.

QUARTER SAWN
More expensive than plain sawn material
Quarter sawn wood has an amazing straight grain pattern that lends itself to design. Quarter sawn lumber is defined as wood where the annular growth rings intersect the face of the board at a 60 to 90 degree angle. When cutting this lumber at the sawmill, each log is sawed at a radial angle into four quarters, hence the name. Dramatic flecking is also present in red oak and white oak.  Find out more.

QuartersawnRiftsawnLumberDifference_Diagram3

Comparison of typical cutting methods for each type of lumber

RIFT SAWN
Most expensive, least common
Rift sawn wood can be manufactured either as a compliment to quarter sawn lumber or logs can be cut specifically as rift sawn. In rift sawn lumber the annual rings are typically between 30-60 degrees, with 45 degrees being optimum. Manufactured by milling perpendicular to the log’s growth rings producing a linear grain pattern with no flecking. This method produces the most waste, increasing the cost of this lumber. Rift sawn lumber is very dimensionally stable and has a unique linear appearance.  Refer to additional pictures.

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