Dry rot is a general term for the damage caused by several species of wood-eating fungi, and despite the terminology, they need moisture to survive. The most destructive type is brown rot, which, unlike white rot, can survive even if the wood is not wet — feeding on the moisture in the humid air. You can repair a dry rot-infected stud, but before you do, you need to eliminate the source of the moisture. That may involve stopping a plumbing or wall leak or installing a more effective moisture barrier. If the moisture source remains as it is, the rot will return.
- Uncover the rotted area of the stud by cutting away drywall with a utility knife and drywall saw. The chances are that the drywall is also moist and moldy, and if so, cut out the entire damaged section. The more of the rotted stud you expose, the better.
- Find the source of the moisture and take steps to correct it. Give the wood time to dry out. Depending on its condition, the humidity in the house, and the weather, it may need several days or even a week.
- Chip the rotted wood out of the stud, using a stiff putty knife and a flathead screwdriver. Vacuum the area when you are done.
- Replace the wall covering. You can drive screws and nails into the putty — it’s as strong as, or even stronger than, the wood.