Common grades (A, B, C, C-plugged, D) are stamped on sheets (e.g., AC = A face, C back). "X" denotes exterior glue, while marine-grade uses A/B veneers with no core voids. C-plugged (higher than C-grade) is ideal for underlayment, and Dunn Lumber’s custom SF34 panel features a knot-free B face.
Standard panel sizes: 4x8’, 4x9’, 4x10’ (with 5x8’, 5x10’ options). Thicknesses range from 3/8" to 1.5" (industrial), with most mills maxing at 1 1/8" due to pressing time.
To calculate shipping weight:
- 4x8’ panel = 32 sq.ft.
- Weight = 0.032 x lbs per MSF (e.g., ½" panel = 0.032 x 1,280 = 40.96 lbs/sheet).
Most plywood uses exterior glue; hardwood varieties use specialized adhesives for finish/color.
½" sheathing panels vary in plies (3-ply, 4-ply, 5-ply) due to veneer thickness (e.g., 4-ply uses 1/8" veneers). Thickness tolerance follows APA standards, allowing minor variations while meeting minimum requirements. Mills may differ in quality, but U.S./Canada mills meet high standards; choose based on project needs (e.g., Dunn’s premium B-face underlayment for durability).
