Final answer:
The worst-case scenario for foundation placement relative to grade level is when the top of the foundation wall is three inches below grade, as it significantly increases the risk of water penetration and damage to the structure.
Step-by-step explanation:
The question seems to be related to the construction and engineering of building foundations. When considering the worst-case scenario for the positioning of a foundation in relation to grade level, let's analyze the options provided:
- A. The top of the foundation wall is 16 inches above grade: This is often seen as a good situation as it helps in preventing water from pooling against the side of the house which can lead to moisture problems.
- B. The top of the foundation is at grade: This might lead to water issues as there is no elevation to aid water run-off.
- C. The top of the foundation wall is three inches below grade: This scenario poses a significant risk for water penetration and damage to the structure since water can easily accumulate at the base of the wall.
- D. The top of the foundation is eight inches wide: This characteristic is more about the thickness of the wall rather than its relation to grade level and does not necessarily represent a negative case in itself.
Considering the options above, the worst-case scenario is C. The top of the foundation wall is three inches below grade, owing to the high probability for water issues and the potential structural damage that can ensue.