T-111 Siding Problems !exclusive! Now

: Temperature swings and moisture cycles cause the wood to expand and contract. If not installed with proper expansion gaps, panels will bow outward or buckle.

This is the most common and severe issue. T-111 is made of wood veneers (plywood) or wood strands (OSB) glued together.

The grooves aren’t just cosmetic — they create vertical channels that suck water upward by capillary action. Once the bottom edge touches damp ground or a splash zone, moisture wicks into the untreated plywood core. Result: swelling, delamination, and a perfect mold buffet.