Panel boards on a wood retaining wall should be installed on the back of the posts.

• A. On the center of the posts
• B. On the front of the posts
• C. On the back of the posts
• D. Diagonally across the posts

Answer: (C)

Panel boards in a wood retaining wall serve as the facing that holds back the soil, while the posts provide the primary resistance to lateral earth pressure. Installing the panels on the back side of the posts positions the boards so that the posts bear the outward thrust and the fasteners grip into the stronger, interior side of the wall. This orientation helps keep the wall stable, prevents the boards from being pried away by soil pressure, and reduces the chance of movement or failure. If the panels were on the front side, the outward force would more readily push them away and loosen the connections, compromising the wall’s integrity.