Utilizing Small Timber Volumes
with Portable Sawmills:

Guidelines for Log and Lumber Measurement

Forest insect and disease pests cause an estimated growth loss and mortality in excess of \$8 million each year in South Carolina forests. An integrated pest management (IPM) approach on your forest lands could significantly minimize your potential losses. Efficient utilization of damaged or killed timber is an important part of forest IPM.

Forestry Leaflet 15
Revised October 1997

Portable sawmills can be economically beneficial to private landowners who have small volumes of timber which need to be salvaged or harvested. The end-product from a portable sawmill is quality lumber which can be either sold at a profit or used to meet a landowner’s personal needs. Portable sawmill operators are located throughout the state and most base their fees on the board foot (bf) volume sawn. When working with a portable sawmill operator, landowners are responsible for felling the trees and skidding the logs to a predetermined spot. Landowners must be certain that their total log volume meets the minimum volume requirements of the sawyer. Knowledge of the total log volume also allows a landowner to estimate the fee a sawyer will charge. This guide provides practical information on how to measure the volume of logs and lumber, as well as estimating the approximate cost of having the logs sawn.

How to Measure Log Volume

To estimate the board foot volume of a log, measure the length of the log and the diameter inside the bark at the small end. Use Table 1 to find the board foot volume for the log length and log diameter combination. For example, if the log is 8 feet long, and the diameter is 10 inches Inside the bark at the small end, the volume would be 28 bf. To find the volume of several logs, simply add the individual log volumes together. Three logs with individual volumes of 30, 40, and 50 bf would have a total bf volume of 120. For example:

30 + 40 + 50 = 120 bf.

Table 1. Scribner Log Rule

 Diameter in Inches Log Length in Feet 6 8 10 12 14 16 Volume in Board Feet 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 5 8 11 16 21 26 32 39 46 54 62 71 81 91 102 113 125 138 151 165 179 194 210 226 243 6 11 15 21 28 35 43 52 62 72 83 95 108 122 136 151 167 184 202 220 239 259 280 301 324 8 13 19 26 34 44 54 65 77 90 104 118 135 152 170 189 209 230 252 275 299 324 349 376 404 9 16 23 32 41 52 64 78 92 108 124 142 162 182 204 226 250 276 302 330 359 388 419 452 485 11 18 26 37 48 61 75 91 108 126 145 165 189 213 238 264 292 322 353 385 418 453 489 527 566 12 21 30 42 55 70 86 104 123 144 166 189 216 243 272 302 334 368 403 440 478 518 559 602 647

How to Measure Lumber Volume

Sawyers base the bulk of their charges on the board foot volume of the lumber sawn. Landowners can determine the volume of a piece of lumber by using Table 2. For example, the volume of a 2 x 4 Inch board, 6 feet long, would be 4 bf. To find the volume of several boards simply add the individual board volumes together.

Table 2. Lumber Scale

 Diameter in Inches Lumber Length in Feet 6 8 10 12 14 16 Volume in Board Feet 1 x 3 1 x 4 1 x 5 1 x 6 1 x 7 1 x 8 1 x 10 1 x 12 2 x 4 2 x 6 2 x 8 2 x 10 2 x 12 2 x 14 3 x 6 3 x 8 3 x 10 3 x 12 4 x 4 6 x 6 1.5 2.0 2.5 3.0 3.5 4.0 5.0 6.0 4.0 6.0 8.0 10.0 12.0 14.0 9.0 12.0 15.0 18.0 8.0 18.0 2.0 2.6 3.3 4.0 4.6 5.3 6.6 8.0 5.3 8.0 10.6 13.3 16.0 18.6 12.0 16.0 20.0 24.0 10.6 24.0 2.5 3.3 4.0 5.0 6.0 6.6 8.3 10.0 6.6 10.0 13.3 16.6 20.0 23.3 15.0 20.0 25.0 30.0 13.3 30.0 3.0 4.0 5.0 6.0 7.0 8.0 10.0 12.0 8.0 12.0 16.0 20.0 24.0 28.0 18.0 24.0 30.0 36.0 16.0 36.0 3.5 4.6 6.0 7.0 8.0 9.3 11.6 14.0 9.3 14.0 18.6 23.3 28.0 32.6 21.0 28.0 35.0 42.0 18.6 42.0 4.0 5.3 6.6 8.0 9.3 10.6 13.3 16.0 10.6 16.0 21.3 26.6 32.0 37.3 24.0 32.0 40.0 48.0 21.3 48.0

How to Estimate Cost

Figure 1 is used to estimate the sawyer’s charge based on either the total log volume or the total board foot volume. To estimate this cost:

1. Determine total volume for logs or boards as described In the previous section.
2. Find this volume amount on the horizontal axis, labeled "Board Foot Volume of Logs."
3. Move directly upward on the graph until intersecting the appropriate cost line.
4. Move to the vertical axis to find the approximate cost.

For example, to have a sawyer saw 2000 bf at 10 cents a board foot (\$100 a thousand board feet) the charge would be \$200. The graph gives an approximate cost. Actual cost may vary depending on the exact fee structure of the sawyer.

 Figure 1. Sawyer cost per log volume

Who Benefits

A number of problems are encountered by landowners who wish to sell small volumes of timber, whether from healthy, mature trees or from salvaged trees damaged by pests or storms. Often, loggers will not buy small volumes of timber because the high costs involved in moving equipment and personnel make this practice uneconomical. When a logger is willing to cut small volumes of salvageable sawtimber, landowners will normally have to accept a substantial reduction In price to compensate the logger for these additional costs. As illustrated in Figure 2, the price range paid for salvaged trees is consistently lower than their potential value. Landowners can benefit from the services of a portable sawmill operator by making use of sawtimber-sized trees that would otherwise go to waste or be under-utilized. Therefore, portable sawmills can provide landowners with a readily available supply of lumber that may be worth two to three times the cost of sawing.

 (Trees 10" DBH with 2.5 logs) A. Price range of green sawtimber B. Pulpwood price range; commonly paid for salvaged timber Figure 2. Value per timber volume

C. Karpinski, Former Forester I
S. W Fraedrich, Former Forester I

Department of Forest Resources