Solid-concrete blocks are ideal for building on-grade foundations. The blocks are aligned in rows and checked for level with a long, straight 2x4 and a 4-ft. level.
The success or failure of any outbuilding relies heavily on its foundation. No structure -- regardless of how well it’s designed or built -- will survive for very long on a weak or poorly made base. Therefore, choosing and building a proper foundation is the single most important construction step in the entire project.
On-grade vs. frost-proof foundationsShed foundations fall into two basic categories: on-grade and frost-proof. On-grade foundations (sometimes called “floating foundations”) sit right on the ground and are sufficient for all but the very largest outbuildings. They’re also the quickest and simplest to build because they don’t require you to dig deep holes or pour concrete footings or piers. On-grade foundations are usually made of pressure-treated lumber or solid-concrete blocks.
Permanent, frost-proof foundations are more difficult to build, but they’re by far the strongest and longest lasting. These types of foundations are designed for cold-weather regions where ground movement caused by freeze/thaw cycles can affect a building.
The best foundation to build for your shed will largely depend on what the building inspector recommends, but keep in mind that it’s often based on three key factors: the shed’s size, the region of the country in which you live, and the type of shed floor you desire.