Shed Foundation Options and Cost

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Investing in a shed can be one of the best ideas a homeowner can do. Of course, they are practical for safely storing all of the tools you need to keep your lawn and garden looking great as well as protect them from getting stolen, but sheds can also be used for family fun and activities. As an added bonus, sheds also normally increase the value of homes. 

Before building or buying a shed, you will want to make sure your plan will align with your local building department’s laws and your homeowner’s association’s bylaws (if applicable), but after that the specifications are up to you. This includes what kind of foundation you want your shed to have. It is important to remember that extreme weather conditions such as a tornado can blow over any shed (and house) regardless of the foundation, so although picking a solid, strong foundation is critical to your shed’s longevity, there is no guarantee it can withstand all weather conditions. 

The two general kinds of sheds are on-grade and permanent. On-grade ones are movable, and permanent ones stay put. Below are some of the foundation options available when building or buying a shed. 

Wood

Wood is one of the most popular foundations for sheds. It is usually more economical than concrete and doesn’t require as much excavation and other manual labor. However, wooden foundations are not recommended if you have a slope of more than 24 inches and they also usually cannot support much larger items (e.g. a boat). However, if you are just needing a shed for some storage and your lawn and garden equipment, a wood foundation might be right for you. 

Most, if not all, wooden sheds should have some sort of anchoring to prevent shifting and alignment issues. These issues can make it really hard to maintain an even floor and can also cause cracks that may allow bugs and other pests in. Shifting can also make it difficult for you to open and close the doors of your shed, which is not only annoying but can become even worse over time. A couple widely used wooden foundations are skid foundations and timber frame foundations.  

Skid Foundations: People who plan on moving their shed often opt for a skid foundation because it is more easily movable than other foundation types. Skid foundations generally have a floor structure built on top of big pieces of lumber, normally 4×4, 4×6, and 6×6. These are not permanently attached to the ground so they allow owners to move them whenever wherever they need to go. “Skids” may also be called runners or deadmen and are oftentimes placed on top of a bed of gravel to lessen the chance of the lumber rotting. 

Timber Frame Foundations: A timber frame foundation is one of the most practical foundations for a shed while still leaving builders with a lot of customization abilities. It’s exactly what it sounds like – the walls are built onto a wooden frame on a bed of gravel. This comes in handy because it allows you to choose whatever flooring you want for your shed whether that is concrete, marble, slate, and so on. These generally use 4x4s, 4x6s, or 6x6s that have been pressure-treated. Half-lap corner joints are used to join the timbers or landscaping spikes can be used. These can cost about $50 per square foot of the wood material. 

Concrete

On-grade sheds made with concrete slabs are one of the more popular sheds, especially for beginners looking for an “easier” shed and people who do not need a huge shed. These feature concrete pavers that will sit on the ground, which you’ll have to lever first. That said, sand can usually make this easier for you. Pavers vary in size, shape, color, and material, but their cost normally sits between $100 and $200. 

If you have the budget for it, a permanent full-concrete shed foundation may be the best option for you. Firstly, it won’t rot like a wood one potentially could, and it is also sturdier than a wooden one, meaning that the chances of it shifting are much slimmer. Cleaning a concrete foundation also may be easier than cleaning other types of foundations, which makes it easier to maintain and have it stay looking as good as new. While cost is hard to calculate due to varying sizes of sheds, multiply the length and width of your shed by $4.50 and that will give you a ballpark estimate. 

As mentioned, concrete foundations are normally the most expensive and will likely turn out to be a large chunk of your overall cost, so shop around a bit before making a decision on where to buy it.

Wood and Concrete

Some people, especially those who live in very windy places, prefer to build sheds using both wood and concrete. This type of foundation features wood that is “anchored” down with concrete anchors. The actual shed and floors are made of wood but the concrete will strongly adhere them to the ground so that the chances of the shed shifting is minimal and the force of wind will have a lesser chance of knocking the shed over. Two options for this are basic concrete blocks and deck blocks. 

Basic Concrete Blocks: Some people decide to put a non-concrete shed on top of some concrete blocks around the edges and corners. Although this type of foundation might take some math to get the measurements figured out, it eliminates the need to level the ground. It is hard to estimate a cost without knowing how many concrete blocks you need and what size you should get, but generally these are less expensive than other options and can cost between $50 and $100. Of course, you would have to monitor it to make sure it isn’t sinking. 

Deck Blocks: Along the same lines, you may also want to use deck blocks, which are pre-formed concrete rectangles that can be scattered on the ground before placing a wooden shed on top of. These are similarly priced to concrete blocks. 

Plastic

One of the newer types of foundation for a shed is plastic. Plastic foundations are normally made out of recycled materials and can be placed on a level ground to support your shed. The openings of the holes are usually filled with some sort of gravel such as pea gravel, which will prevent a serious buildup of moisture from a bad storm. Depending on size, a very large plastic foundation can cost upwards of $300. 

Overall, the kind of foundation you choose for your shed will depend on its size, your budget, and whether you want an on-grade shed or a permanent one. Therefore, it is critical to know your needs and perhaps reach out to an expert for advice and help before getting started on your new shed adventure.