Finger-joined lumber is typically produced from lumber that has no more than 19% moisture content [S-Dry] for ease of manufacturing the joint to meet the strict quality control standards. For this reason, finger-joined lumber is almost always sold as S-Dry.
Adhesives used in the manufacture of VERTICAL STUD USE ONLY finger-joined lumber are not suitable for joining wet lumber and therefore only S-Dry lumber is processed in order to ensure a quality joint. It is also important to avoid exposing the end product, VERTICAL STUD USE ONLY finger-joined lumber, to excessive moisture while in storage or during construction. Although VERTICAL STUD USE ONLY finger-joined lumber will resist short term exposure to moisture generally expected during construction, like any wood product intended for dry use, it should be allowed to dry after wetting before or during installation.
Information in this section comes from Wood Design & Building #12 by Michel Boudreau P. Eng.