Abstract
To evaluate the anti-termite efficacy of a preservative containing boric compound and phoxim (commercial name Koshi Long-P), laboratory and field tests according to JWPAS (Japan Wood Preserving Association Standard) -11 and JWPAS-12 were carried out.
The results indicated :
1. The values of preservative retention of treated specimens met the AQ (Approved Quality of treated timber registered by Japan Housing and Wood Technology Center) requirements.
2. In the laboratory test, the mass losses of treated specimens, except for SP (Structure Plywood)-1 specimens which were the products of inadequate fixation of boric acid, were less than 3%, in contrast to those of the untreated specimens, 24.5% for sawn timber, 16.6% for plywood, and 33.3% for softwood LVL (Laminated Veneer Lumber). In the case of hiba plywood, the mean mass losses of untreated specimens were less than 3% like treated specimens.
3. After 13 months of the field test in the subtropical area (Ogasawara Island, Japan), no attack by termites against treated specimens was observed, in contract to the mass losses of the untreated specimens, 89.8% for sawn timber, and over 50% for other board materials.
