What is the correct statement regarding unprotected sill plates on a foundation?

What is the correct statement regarding unprotected sill plates on a foundation?

• A. Leave it alone
• B. Use a layer of bitumen between sill plate and foundation
• C. Protection is not needed if it is 8 inches above grade
• D. Protection is not needed if it is 6 inches above grade

Answer: (C)

The main idea is how far a wood sill plate on a foundation must be kept from finished grade before additional protection is required to guard against moisture and termites. When the sill plate sits 8 inches or more above grade, protection is not required. The risk of moisture wicking from the soil and pest access drops enough at that height that code typically allows skipping extra barriers like a bitumen layer. If the clearance is less than 8 inches, protective measures are commonly needed, such as a layer of bitumen between the sill plate and foundation to prevent moisture intrusion. The option about 6 inches is not sufficient clearance, so protection would still be required there. Leave it alone is not correct unless the 8-inch threshold is met.

The main idea is how far a wood sill plate on a foundation must be kept from finished grade before additional protection is required to guard against moisture and termites. When the sill plate sits 8 inches or more above grade, protection is not required. The risk of moisture wicking from the soil and pest access drops enough at that height that code typically allows skipping extra barriers like a bitumen layer. If the clearance is less than 8 inches, protective measures are commonly needed, such as a layer of bitumen between the sill plate and foundation to prevent moisture intrusion. The option about 6 inches is not sufficient clearance, so protection would still be required there. Leave it alone is not correct unless the 8-inch threshold is met.