This photo was taken in a crawl space of a ranch style house built in the 1960’s. There was a sliding glass door above. Sliding door areas are susceptible to moisture ingress from the exterior, if they are not properly installed and maintained. This photo shows rotted structural wood members (darker / blackened areas) under the door area and a temporary repair (the white pieces.) Instead of addressing and correcting the cause of the wood rot, a secondary sill / support was installed. The newer wood itself was starting to rot. The wood members of the “repaired” section were actually wet at the time of this inspection. They will suffer the same fate as the rim joists, floor boards, and sill plates, unless the water penetration around the door is stopped. In addition, this situation will encourage insect activity and allow conditions for mold to develop.