To protect wood framing and siding from moisture, how high should foundations extend above the finished grade?

The correct answer focuses on the principles of construction that aim to prevent moisture from penetrating wood framing and siding. Specifically, a foundation should extend above the finished grade by a minimum of 6 to 8 inches. This height helps ensure that rainwater and surface runoff are directed away from the structure, reducing the risk of moisture damage.

By extending the foundation to this height, you create a barrier that can prevent water from pooling around the base of the building. This is crucial because moisture that infiltrates the wood can lead to issues such as rot, mold, and structural compromise over time. Additionally, maintaining this height aligns with building codes and best practices, which often specify similar ranges to ensure adequate protection against moisture.

Other height options, such as 4 inches or more than 8 inches, may not conform to the specified guidelines effectively. A foundation height of less than 6 inches lacks sufficient clearance to direct water away from siding and framing, while exceeding 8 inches beyond what is typically required might not provide additional benefit and could lead to unnecessary excavation or landscaping adjustments.