Engineered Properties of Wood, Wood Materials and Structures
FS-FPL-4714

Strength Effects: Incising and Preservative Treated Wood
Principal Investigator: Dr. Jerrold E. Winandy
March 1, 2000

Project Objective:
Development of a basic understanding of how, why, and to what extent incising and preservative treatment effects the mechanical properties of lumber, timber, and glulam.

Tangible Benefits:
To develop a data base and understanding of principles from which practical guidance can be given to the engineering community and to standards organizations for a rational basis for developing design adjustment factors for incised and preservative-treated lumber and glulam.

Results:
A series of studies evaluated nominal 2 x 4 Douglas fir, Hem Fir, and SPF-south lumber incised before treatment with two commercial incising patterns and then treated with CCA, ACZA, or ACQ-B preservative. The results described the effects of incising and preservative treatment on bending strength (pdf1998/winan98a.pdf) and torsional shear strength (pdf1998/morre98a.pdf).

Using this data, a predictive “Incising Effects Model” was developed for nominal 2-inch thick lumber (pdf1998/winan98b.pdf). That model reasonably predicted the effects of incising and preservative treatment on bending stiffness and bending strength. Additional work is needed to verify the application of the predictive “Incising Effects Model” to timber and glulam.

Users:
Wood engineers, treaters

Funding:
State and Federal funding, industrial support