Sill Plate
Definition and meaning of Sill Plate in real estate.
A sill plate is the bottom horizontal wood member of a wall frame that rests directly on top of the concrete foundation or slab. It serves as the anchoring point where the wood framing of the home is secured to the masonry foundation.
In more detail
In modern construction, the sill plate must be made of pressure-treated lumber to resist rot and termites, as it is in direct contact with concrete, which naturally absorbs moisture. It is secured to the foundation using heavy anchor bolts embedded in the concrete to keep the house from shifting during high winds or earthquakes.
A sill sealer, which is a thin foam strip, is typically placed under the plate to block drafts and pests from entering the home. Because it sits at the very bottom of the wood structure, any water pooling around the foundation can rot the sill plate, leading to expensive structural repairs.
Key facts
| Category | Property Types & Construction |
|---|---|
| Required Material | Pressure-treated wood (to resist rot and insects) |
| Secured By | Anchor bolts embedded in concrete foundation |
| Location | Directly on top of the concrete foundation |
During the framing phase of a new house, workers bolt pressure-treated sill plates to the top of the foundation wall to create a level base for the floor joists.
Frequently asked questions
Why does a sill plate need to be pressure-treated?
Concrete absorbs moisture from the ground, which will transfer to untreated wood and cause rot and termite infestations.
How do you repair a damaged sill plate?
Repairing a rotted sill plate requires temporarily jacking up the house framing to support the load while the damaged wood is cut out and replaced.