Foundation Sill Plates Video

Sill Plates, or Sole Plates, are Treated Horizontal Lumber that are Anchored to Foundation Walls

By Mark J. Donovan




In this video 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 2×4, 2×6, 2×8 or 2×10 treated lumber that is bolted or strapped down to the foundation walls.

Sandwiched in between the treated foundation sill plate and concrete foundation walls is a thin foam insulation pad. Though the top surfaces of foundation walls are reasonably smooth they are not perfect. By placing the foam insulation pad between the foundation sill plate and the foundation wall, air infiltration into the basement or crawl space is prevented. In addition, the foam insulation padding also helps to prevent insect infestation into the home.

Home Addition Bid Sheets

Foundation sill plates are attached not only to the horizontal sections of the concrete foundation wall but also to the vertical sections where there are step-ups in the foundation wall.


For more help on building a home addition, see HomeAdditionPlus.com’s Home Addition Bid Sheets. Our Home Addition Bid Sheets provide you with the knowledge and information on how to plan a home building project, and what to look for when hiring contractors. They also include detailed cost breakdown tables and spreadsheets for estimating your own new home construction building costs.

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