A sill is the foundational bottom plate that rests directly on the masonry foundation or piers, supporting the vertical studs of the wall framing. In window and door construction, it refers to the flat bottom piece of the frame that sheds water away from the opening. It is a critical transition point that transfers the load of the building down to the earth.
Heard on the job
We need to bolt the treated sill down to the foundation before we can start standing up the wall frames.
Also heard as
- sill plate
- mud sill
- sole plate
Do not mix it up with
- Wall plate: A sill is the bottom plate resting on the foundation, while a wall plate generally refers to the top horizontal member of a framed wall.