Final answer:
Building foundations should extend a minimum of 6 - 8 inches above grade to protect against moisture and ensure the structure's stability and longevity. option b is correct .
Step-by-step explanation:
Foundations of a building should extend at least 6 - 8 inches above grade. This is to provide adequate separation from the ground to protect the building material from moisture, which can lead to deterioration over time. It is important for the foundation to be properly sized and constructed to ensure the stability and longevity of the structure it supports.
Foundations should extend at least a specified distance above grade level to ensure structural stability, prevent moisture intrusion, and comply with building codes. The minimum height above grade for foundations is often determined by local building regulations and can vary based on factors such as climate, soil conditions, and the type of construction.
As a general guideline, foundations are designed to extend above grade sufficiently to provide proper support for the structure and to prevent water infiltration. This extension typically includes features like a foundation wall or stem wall. Commonly, building codes require a minimum of 6 inches to 12 inches of foundation wall above finished grade. However, specific requirements may vary, and it's crucial to consult local building authorities and adhere to applicable codes to ensure that foundations meet the necessary standards for safety, durability, and compliance with local regulations.