Mobile homes are usually mounted on grade-level wooden or concrete blocks, with the trailer wheels removed. They are typically skirted with vinyl or aluminum siding, or painted plywood sheathing. arizona mobile home community are sometimes installed on concrete block foundations, and it can be difficult to determine whether the foundations are mounted below the frost level, because the crawl spaces are normally back-filled to grade level. We've seen the odd mobile installed on a full-depth, finished basement.