Effect of CCA-Treating and Air-Drying on the Properties of Southern Pine Lumber and Plywood


  • Andy W. C. Lee


Southern pine, plywood, CCA-treating, air-drying, bending, compression, shear, glueline shear, equilibrium moisture content


Matched samples of southern pine lumber and plywood were treated with CCA-preservative and then air-dried. When conditioned at the same relative humidity and temperature, the treated lumber and plywood had significantly higher moisture content than untreated samples. The CCA-treating and air-drying did not affect the bending and shear properties of lumber when retention level was 0.6 PCF. Compressive strength of treated lumber was reduced by 9% and it was attributed to the higher EMC associated with treated lumber. Bending and glueline properties of treated plywood were reduced by about 10% because of the increased EMC of treated material.


American Society of Testing and Materials. 1978. Annual book of ASTM standards, Part 22. Philadelphia, PA.nBarnes, H. M., and P. H. Mitchell. 1983. The effect of redry schedule on the strength of CCA-treated southern pine dimension lumber. Paper presented at Treated Wood Products Session, FPRS Annual Meeting, Norfolk, VA.nBendtsen, B. A., L. R. Gjovik, and S. P. Verrill. 1983. Mechanical properties of longleaf pine treated with waterborne salt preservatives. U.S. Forest Products Laboratory, Research Paper FPL-434.nCountryman, D., and Staff. 1957. Effect on plywood strength of preservative treatment. Report No. 74, Douglas Fir Plywood Association, Tacoma, WA.nLee, W. C., and E. J. Biblis. 1979. Effect of moisture on flexural properties of clear southern pine plywood. For. Prod. J.29(11):43-49.nWinandy, J. E., B. A. Bendtsen, and R. S. Boone. 1983. Effect of delay between treatment and drying on toughness of CCA-treated southern pine. For. Prod. J.33(6):53-58.n






Research Contributions