How far must concrete walls extend above finished grade?

The requirement for concrete walls to extend above finished grade is crucial for preventing moisture intrusion that can lead to structural damage over time. The standard that dictates this dimension indicates that concrete walls should extend at least 4 inches above the finished grade. This height helps ensure that water runoff from rainfall or irrigation does not pool against the wall, which could lead to issues such as water seepage, mold growth, and deterioration of the concrete.

When walls are set to this height, they provide adequate protection from the elements while allowing for proper drainage away from the foundation. By adhering to the guideline of a 4-inch extension, builders can create a more resilient structure, minimizing potential damages and costly repairs in the long run. Thus, the correct answer reflects an important component of building codes designed to enhance the longevity and durability of residential structures.