
Gravel under concrete footing - GreenBuildingAdvisor
Apr 01, 2015· Crusher-run gravel compacts well but does not drain very fast -- at least not as fast as 3/4-inch crushed stone (no fines). Talk to a soils engineer if you are worried -- but in my experience, either crusher-run gravel (compacted) or 3/4-inch crushed stone can be used under footings. So can rigid foam. An engineer may disagree.