Decking Diaphragms

Glued laminated decking may be used to develop diaphragm / in-plane lateral load resistance in the same way lumber sheathing may be used.  Lumber sheathing may be used transversely (perpendicular to framing members) or diagonally (or double-diagonally).  Glued laminated decking may also be used in combination with structural panel sheathing.  To resist relatively higher in-plane loads structural panel sheathing may be installed over the decking.

Transverse, Diagonal, and Double Diagonal

For 2 in. Nominal Decking - See Lumber Diaphragms

See design procedures and allowable load tables in the Western Woods Use Book, Western Wood Products Association, Portland, OR, www.wwpa.org.

 

Nominal Unit Shear Values for Wood-Frame Diaphragms (Lumber sheathing 1 in. and 2 in. nominal) are provided in Table 4.2C of the National Design Specification for Wood Construction – ASD/LRFD Supplement - Special Design Provisions for Wind and Seismic, American Wood Council, American Forest & Paper Association, Washington, D.C..

 

For 3 in, 4 in., and 5 in. Nominal Decking

See design procedures and allowable load tables in the Western Woods Use Book, Western Wood Products Association, Portland, OR, www.wwpa.org.

 

Decking with Structural Panel Sheathing Overlay

See: National Design Specification for Wood Construction – ASD/LRFD Supplement - Special Design Provisions for Wind and Seismic, American Wood Council, American Forest & Paper Association, Washington, D.C. (www.awc.org / www.afandpa.org).