01/29/2026
We were out visiting a customer and addressed the question this week. "Are moldy joists a problem?" "What causes them?" Yes, and they can become very expensive to fix later on down the road. Mold on joists is caused by excessive humidity in the air and potentially standing water on the floor of a crawl space. A single room subfloor replacement can cost on average $13k (Angi). The way to stop mold in its tracks is to dry the space out. Mold fogging is another great option. But as they say, an ounce of prevention is worth a pound of cure. It's so cheap to protect your home with a dehumidifer and v***r barrier compared to the structural costs of ripping out and replacing wood.
