Sill Sealer
Definition and meaning of Sill Sealer in real estate.
Sill sealer is a flexible foam strip or other sealant material placed between the top of a concrete foundation wall and the wooden sill plate.
In more detail
This material serves as a gasket to seal uneven gaps, which prevents drafts, moisture penetration, and insect entry into the home. It is installed during the framing stage of construction, just before the wooden framing members are bolted to the concrete. By blocking drafts, it improves energy efficiency and helps prevent wood rot caused by moisture transfer from the concrete.
Home buyers and inspectors should verify its presence in new construction to ensure proper building techniques were followed.
Key facts
| Category | Property Types & Construction |
|---|---|
| Common material | Polyethylene foam |
| Typical timing | Framing stage of construction |
| Primary purpose | Moisture barrier and draft prevention |
During the construction of a new home, the framing crew rolls out a blue polyethylene foam sill sealer along the top of the concrete foundation wall before placing and bolting down the pressure-treated sill plate.
Frequently asked questions
Is sill sealer required by building codes?
Yes, most modern building codes require a sill sealer or similar gasket to prevent air leakage and contact between wood framing and concrete.
Can you install sill sealer on an existing house?
It is very difficult to install a foam sealer after construction is finished, but owners can use caulking or expanding foam to seal gaps in existing homes.