Chapter 3.     Stacked Roundwood, Preservative-Treated
Products, and Construction Logs

Stacked Roundwood

      Cord Measure

           • Standard rough cord

            •Long cord

            •The unit

           • Face cord

            •Volume of solid wood in a cord

      Stere Measure

      Conversions Between Cords and Steres

      Cord and Stere Weight

Preservative-Treated Products

         Pole Measurement and Specifications

            •Dry, finished poles

            •Barky pole stock

      Pole Volume

           • AWPA methods

            •Manufacturers' volume tables by pole class

      Pole Weights

           • Estimating weight density

            •Manufacturers' pole shipping weight tables

        Piling Measurement and Specifications

            •Finished piles

            •Barky piling stock

      Piling Volume

      Piling Weights

      Conversion of Pole and Piling Measures to Metric Units

      Ties

      Lumber

Construction Logs

      Chapter 3. Stacked Roundwood, Preservative-Treated Products, and Construction Logs

Stacked Roundwood

Cord Measure

Standard Rough Cord.     A standard rough cord occupies 128 gross cubic feet (3.62 cubic meters) usually comprising 4 foot long split or unsplit roundwood, generally with bark, stacked in a pile 4 feet high and 8 feet long. In some situations, stacks of longer pieces (such as 8 foot lengths) are estimated in terms of standard rough cords.

Long Cord.     A long cord is made up of 5 foot long pieces in a stack 4 feet high and 8 feet long, occupying 160 gross cubic feet (4.53 cubic meters). The long cord is 1.25 times greater than the standard cord and is often used in the southern United States.

The  Unit.     The long cord is sometimes referred to as a unit. In some cases, this term refers to a cord comprising pieces 5' 3" long in a 4 foot high by 8 foot stack occupying 168 gross cubic feet (4.76 cubic meters).

Face Cord.     This term is sometimes used for firewood and refers to stove-length pieces in a 4 foot high by 8 foot stack. With 16 inch long pieces, a face cord occupies one-third the gross space (42.3 cubic feet) of a standard rough cord. With 24 inch long pieces, it occupies half the gross space (64 cubic feet) of a standard rough cord.

Volume of Solid Wood in a Cord.     These cord measures are not a very accurate indication of the actual solid wood volume, because the amount of air space occupied varies with the diameter, length, bark thickness, and condition of the pieces. Condition refers to crookedness as well as surface roughness caused by limbs.

        Table 3-1 shows that a standard cord of smooth, straight barky softwood bolts from the Great Lakes region ranged from 90 to 100 cubic feet when the midbolt diameter ranged from less than 6 to more than 12 inches (USFS 1935). The range for hard­woods was from 85 to 98 cubic feet, and use of 8 foot rather than 4 foot bolts reduced these figures by 2 to 3 cubic feet. When bolts were crooked, rough, and knotty, volume per cord was reduced by about 20 cubic feet.

        In practice, an average conversion factor of 85 cubic feet (2.41 cubic meters) of wood per standard rough cord is often assumed. The USFS assessment assumes 79.2 cubic feet per cord (Appendix 2). Due
to the factors affecting actual volume, the range around this average can easily be plus or minus 20 cubic feet. Table 3-2 shows the effect of species (bark thickness) and diameter on solid content of a standard rough cord (Worthington and Twerdal 1950). Cubic meter equivalents have been added by the author. The 85 cubic feet per cord factor is reached at 11 inches in hemlock and 15 inches in Douglas-fir. If bolts in a cord have been debarked, the values under the total column give a reasonable approximation of the solid wood content.

Stere Measure

        Countries on the metric system use the stere as the standard measure for stacked roundwood. A stere is a space that is one meter on a side, hence one gross cubic meter (35.315 cubic feet, 0.276 standard rough cord). The term stere is used to differentiate this gross space from a solid cubic meter of wood. In some places the term loose cubic meter is used rather than the term stere.

Table 3-1. Solid content of barky standard cord and stere.

Source: Adapted from USFS (1935) by Flann (1962). Original data in Imperial units; metric values added by the author.

Conversions Between Cords and Steres

        Table 3-3 summarizes conversions using the 85 ft³/cord and European solid contents of steres. FAO, in its Yearbook of Forest Products, uses the gross cubic volumes (128 ft³/cord and 1 m³/stere).

Cord and Stere Weight

        Table 3-2 also presents the green weight per cord for Douglas-fir and hemlock. In addition to factors affecting the solid volume of a cord, weight depends on moisture content and species specific gravity. Many organizations have shifted to weight scaling (see Chapter 2, pp. 34-35) to develop local weight factors to account for species and seasonal effects. Since many purchasers are not interested in bark, either the weight factors or the price paid may be adjusted for it.

        Chapter 1 (p. 10) presents procedures for esti­mating the weight of a cord or stere based on the solid wood volume, species specific gravity, and moisture content. The example also illustrates how bark weight can be included or excluded.

Preservative-Treated Products

Preservative treatments are often given to wood to enhance durability, fire retardant ability, and so forth. The major categories are round products such as poles and pilings and sawn products such as railroad ties and lumber treated for decking, sills, and similar applications. The reader should obtain a current copy of the American Wood-Preservers' Association Standards, which has information on various preservatives and retention rates in differ­ent applications. Poles and pilings are round structural members which require processing that includes debarking, peeling to desired shape, seasoning, and usually treatment with preserva­tives. They are relatively straight, free of large knots, and have growth rate (rings per inch) requirements for wood close to their surface. Finished products are commonly sold by the piece.

Source: Worthington and Twerdal (1950).