A.The terms are probably based loosely on the HPVA specifications for water resistance. The HPVA (Hardwood Plywood Veneer Association) set up the designations Type I, Type II, and Type III to denote degrees of water resistance. The Type I designation undergoes the most strenuous testing and can be considered to mean "waterproof." Type II testing is less strenuous and can be considered to mean "water resistant." Type III would not be considered water resistant.

It is important to note that such testing is intended for plywood only and doesn’t really have a lot of meaning outside of plywood gluing. The ASTM has set up similar specifications for determining water resistance. Joints that pass their "wet use" specification are considered to be waterproof. Other industries such as the door industry use other specifications in determining water resistance.

— J.P.