What is the function of a sill plate in framing?

• A. Secures the floor to the foundation and prevents moisture rising
• B. Supports the roof
• C. Anchors electrical wiring
• D. Allows moisture to wick between foundation and framing

Answer: (A)

The sill plate serves as the tying point between the foundation and the wall framing. It sits on the foundation, is fastened securely, and provides a stable base for the studs, transferring loads from the wall down into the concrete foundation. When installed with a moisture barrier and proper flashing, it also helps limit capillary action that could move moisture from the foundation into the wood. This combination—anchoring the floor and wall to the foundation and helping manage moisture transfer—is why the option describing securing the floor to the foundation and preventing moisture rise is the best fit. The roof is supported by the roof structure above, electrical wiring is run through studs and other channels, and the sill plate’s role isn’t to permit moisture to wick between foundation and framing.