Is compression wood acceptable for structural repairs?

• A. Yes
• B. Only for non-structural repairs
• C. No
• D. Only if treated

Answer: (C)

Compression wood has abnormal grain and fibers that grow in a stressed, irregular way, which makes its mechanical properties unreliable. For structural repairs, you need wood with known, predictable strength and good glue compatibility. Compression wood tends to warp, twist, or distort under load, and its bonding with adhesive is inconsistent because the grain isn’t aligned normally. Even if treated, these fundamental defects aren’t corrected, so the material cannot meet the required structural standards. Replacing the defective section with sound material or an approved repair method is the proper approach.