A review is given on soft rot and protection against it, using Cu-Cr-As in hardwoods. The ratio of volume of fiber cell wall to volume of fiber lumen is presented as a major factor influencing final preservative concentration in the fiber cell wall. Soft rot can be controlled in permeable hardwoods with 0.2% Cu (wt./wt. of gross wood). Soft rot may become a problem in treated softwoods. -- AATA