scope:

This specification covers the treatment of different forms and species of wood with various preservatives. It covers treatments of wood items that will be exposed to either moderate or severe hazard of attack by wood-destroying organisms so that an appreciable retention of preservative as well as significant penetration into wood is necessary. Such results are attainable by pressure processes which are acceptable for all products listed in tables I, II, and III. Certain other processes are acceptable for some items provided that they yield the retention and penetration requirements specified herein. These processes include thermal treatments of some species of poles, and double-diffusion treatments of posts, poles, and lumber. Reference is made to TT-W-572, Wood Preservative, Water Repellent, for the treatment of items such as window sash that are used under mild exposure conditions whereby adequate protection is afforded by short-dip treatments.