A rotten sill plate is a common occurrence in old houses—and a big problem.
The sill is the piece of wood closest to the ground, either on a foundation or piers, and is usually a “timber-sized” board: 3×6, 3×8, 4×6, 4×8, and so on. The studs often rest directly on the sill and are toe-nailed in with no bottom plate as you’d find in a modern house. Often installed too close to the ground or otherwise exposed to water or insect infestation, sills can—and do—literally rot out from under the building.
The good news is that many of them can be replaced using common tools, common materials, and common sense. The bad news is that every sill replacement is loaded with individual factors so this article is more about explaining our approach rather than specific steps that’ll cover every job.
That said, one constant is gravity so we know we’ll encounter the same general things on most projects.
- Remove weight from the sill.
- Remove the sill (and any other damage).
- Re-design a sill and/or stud system that meets current code and fits the needs of the space.
- Install.
- Inspect.
- Insulate.
Click here to read more about removing a rotten sill plate by Mark on Extreme How-To.