This stuff is very sticky and never dries. It seals the concrete and is very hard to break through for an excavation. This concrete box ensures that it will not sink and thus means it does not need to be buried as deep. A typical grave is 4 feet deep, 8 feet long, and 3 feet wide.     To start, we need to remove the sod. Sod is tough and holds together pretty well so we need to lift that up first. Think of it as cutting brownies out of a pan.