Mark Donovan of HomeAdditionPlus.com
discusses foundation sill plates, including the use of treated lumber and
foam insulation padding, in this video.
When framing a home or home
addition the first lumber installed on the foundation walls are the
horizontal foundation sill plates. Vertical stud walls are then fastened
to them.
Foundation sill plates are constructed using 2x4, 2x6, 2x8 or 2x10 treated
lumber that is bolted or strapped down to the foundation walls.