Parallam Plus is typically specified for outdoor decks or any situation where the member is exposed to direct rainfall. If the member will be exposed to direct rainfall then Parallam Plus is required. Otherwise, it is up to the design professional to decide if a pressure treated product is needed. Dry use is defined as an environment where the in-service moisture content of the member is less than or equal to 16%.
Please refer to Specifiers Guide TJ-7102 for more information.