Q: I disagree with my builder about what will happen under the garage slab of my new home. There is a trench around the inside on all four walls where they had to dig to install the foundation.

The center of the garage area is undisturbed dirt ... These can be spaced at 4-foot intervals around the interior foundation walls. The concrete slab will rest on these and provide solid support ...

What else would you do to ensure the concrete slab that will be poured ... that needed fill around the foundations and under the slabs. I also built garage additions very similar to yours.

From your description it seems as if your garage slab is about 14 inches below the finished floor of the kitchen. We don't think you'll have to disturb the existing foundation, but you might have ...

Shelby is an editor with an affinity for covering home improvement and repair, design and real estate trends. She also specializes in content strategy and entrepreneur coaching for small ...