Correct Response: A. A major advantage of slab-on-grade foundations over slab-and-crawl-space foundations is that they do not require deep excavations and cement basement walls. This can result in major cost and time savings due to the need for less material and less labor. This can be especially true if blasting is required. One disadvantage is that plumbing and wiring are typically embedded in the cement slab, making them inaccessible (B). Heat loss through the slab (C) is another disadvantage since incorporating insulation is made more difficult. When it comes to protecting footings from weather and humidity (D), the footings of a slab-on-grade foundation are closer to grade, and hence more vulnerable.
