Foundation Options for an Outdoor Shed

The success or failure of your shed relies greatly upon its foundation. Even the best-designed, strongest-built sheds won’t last very long if set upon a weak or poorly constructed base. Therefore, building a strong, durable foundation is arguably the most critical step in building your shed. Tips are from home and property experts:

On-Grade Foundations

The Bell Team, Captive Island Realtors® Suggest: An on-grade foundation is one that sits on the ground. It is not a permanent shed foundation. Therefore, it can be moved if needed. It can be a solid-concrete block, skid, or timber-frame foundation. You would choose one of these if you have a small to medium-sized shed, if you may want to move your shed at some point or if you cannot dig into the ground.

Concrete Block

Knieper Team in Granbury TX real estate suggests: A series of solid-concrete blocks are used to build this type of foundation. They should be laid out in straight rows, evenly spaced from each other. The size of your shed and the lumber being used for the floor joists will determine how many blocks you need and how much space will be between them.

Skid Foundation

Allston MA Realtor Sam Resnick suggests: Skid foundations have been used to support sheds and other outdoor buildings for more than 300 years. Building this type of on-grade foundation is very easy. Using two or more long, straight timbers, lay them on the ground parallel to each other and evenly spaced apart. Build the shed’s floor frame on top of them. A skid foundation takes very little time to build, and it is one of the easiest options.


John Kinnunen, Clearwater Beach Condos for Sale suggests: A timber-frame foundation is made by constructing a rectangular, wood frame and positioning it on top of a bed of gravel. It is very easy to build. The shed walls are then built on top of the frame. One reason timber-frame foundations are so popular is that it accepts a variety of flooring options.

Frost-Proof Foundations

Milburn and Short Hills Real Estate Team,  Miggins Real Estate suggests:Frost-proof foundations are able to support more weight than on-grade foundations, which is why they are often chosen. They are permanent, and building one involves several additional steps. You must dig below the frost line and use concrete and piers to maintain the foundation’s structural integrity. This type of foundation will not shift.

Concrete Piers

Omaha Real Estate Team, Flatwater Realty Suggests: A concrete pier foundation is simply a column of concrete poured into a hole in the ground. If you are building your shed in a cold-weather region, make sure the holes extend below the frost line. This can prevent the adverse effects of frost heave from having an impact on your shed. Two or more rows of piers support the shed’s floor frame.

Poured-Concrete Slab

Miami Condos for Sale, Kenny Raymond offers: A poured-concrete foundation is the best choice for larger outbuildings that will be used to store heavy equipment, such as woodworking machines, tractors, boats, motorcycles, snowmobiles, and cars. There are two basic ways to pour a concrete slab, but only one qualifies as a frost-proof foundation. It’s called a monolithic slab, and the shed floor and the perimeter foundation walls are all poured at the same time.

The second type of concrete floor is known as a floating slab or an on-grade slab. It’s simply a 4 to 6-inch thick layer of concrete that sits right on the ground. This type of shed floor should never be used when the building codes call for a frost-proof foundation.

There are a lot of options when it comes to your foundation. Choose the right foundation for your land and lot and you’re sure to make your shed last a long time.