What is the maximum surface-area impact allowed for delamination of the plies on a plywood backing?

• A. 25 percent
• B. 10 percent
• C. 50 percent
• D. 5 percent

Answer: (A)

Delamination stops sharing loads evenly between the glued plies, weakening the panel’s ability to carry shear and bending forces. Allowing up to a quarter of the surface area to be delaminated keeps enough intact bond and stiffness so the plywood backing can still perform under normal service. If more area is delaminated, the panel loses too much of its load-transfer capability and would likely require replacement or major repair. So the maximum allowable delaminated surface area is 25 percent.