shed foundations made easy


There are many different types of shed foundations. Make sure you choose the one that is right for your storage shed. Here is a listing of many of the most popular shed foundations along with how they are made and some helpful tips that will enable you to choose the right one for your needs. If you are looking for expert advice on the best foundations and the best portable buildings you can buy, contact Classic Buildings today.


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Shed Foundations

There are two basic categories of shed foundations: on-grade and frost-proof. The type of foundation that you choose will depend on the size of your building, the region where you live, and the type of floor you want.


On-Grade Foundations


on-grade foundation

On-grade foundations are the easiest and least expensive to make


These types of foundations are also known as “floating foundations” because they sit on top of the ground. They are the easiest to build and are the least expensive because you don’t have to dig deep holes or pour concrete footings or piers. This type of foundation is usually made from pressure-treated lumber or solid concrete blocks, and is usually fine for most outdoor sheds. Larger outbuildings will require a frost-proof foundation. The following are some of the more popular on-grade foundation options.


It is better to raise your shed off the ground to protect it from moisture


1. Solid Concrete Blocks: With a solid concrete block foundation, your shed will be supported by a series of concrete blocks that are laid out in straight, evenly spaced rows. The size of your shed will determine how many blocks are needed and how close together they should be placed. Do not use hollow concrete wall blocks as they will not be strong enough to support your shed and will crack and crumble over time. Thicker blocks are placed first and then thinner patio blocks are used to raise one block even with the others if your ground is uneven.

If your site is high and dry you can lay out your blocks right on top of the ground. If you experience rain runoff, you should prepare your site as follows:

  • remove a patch of grass under each block with a shovel
  • press down the soil beneath with a hand tamper
  • cover compacted dirt with 2″ or 3″ of gravel
  • set your concrete blocks on the gravel

2. Frame the Floor into the Beam and Use Concrete Piers: As in method number 3, you can frame the floor into your beams but then raise it up using concrete piers to keep it protected from moisture damage.

3. Use Concrete Piers Underneath Two Beams: You can attach concrete piers to two 2X4 floor beams under your shed to raise it up from the ground. The concrete piers are a better choice than having wood beams sitting on the ground as concrete is not susceptible to moisture damage.

4. Frame the Floor With a Beam in It: You could use two 2X6’s for the floor joists and two 2X8’s for the floor beams. The wooden beams would, however, be in contact with the ground so over time they may rot from moisture damage. This type of construction would make it more difficult to replace the damaged beams.

5. Framed Floor Set on Beams: Frame the floor and set it on top of two beams (such as two 4X4’s) that sit on top of the dirt. This is a better solution than placing your shed floor directly on the ground as this will protect it from moisture. The 4X4’s may become damaged over time but they can be replaced at a lower cost than having to replace the entire floor or the entire shed.

6. Framed Floor Foundation: Frame the floor and set it on the ground. This is a very common method but it is not a very good idea as the moisture in the ground will eventually rot and damage the floor of your shed.



Permanent Frost-Proof Foundations

Permanent frost-proof foundations for storage sheds are more expensive and more difficult to build but they are much stronger, more durable, and will last longer than on-grade foundations. They are designed for cold-weather regions where the frost freeze and thaw cycle can damage your building.


cement foundation

Frost-proof foundations are more difficult to build but they are much stronger, more durable, and will last longer than on-grade foundations


Recommendations for Building Permanent Concrete Slab Foundations

1. Make Sure You Build Any Shed Foundations Below Your Area’s Frost Line

The frost line refers to an imaginary line in your soil, above which the earth can freeze due to the cold winter temperatures. Below this line, the soil is kept warm enough by the earth below that it doesn’t freeze. It is important to place any footings and foundations to the frost line because the ground may heave from the motion of freezing and thawing and could crack or damage your foundation. The frost lines in the State of Missouri vary from 25″ in the north of the state to 12″ in the south. Click here to see a map illustrating the different frost lines.

2. Make sure that your concrete slab is the same width as your storage shed.

3. Try to get your corners as “square” as possible (having 90-degree angles). Your corners should not be more than 1/4″ out of “square.”

4. Your finished slab should be at least 4″ above the grade.


How to Pour a Concrete Slab for Your Shed

You can either hire a handyman to pour your concrete slab for you, or, if you are handy, you could try to do it yourself. The following video will show you the steps involved in pouring an 8X10 shed slab for the beginner.


A concrete slab is a good choice for larger structures


How to Make a Gravel Pad Foundation

An easier alternative to a concrete pad is to make a gravel pad for your shed foundation. It is best to use coarse gravel as opposed to round gravel as the coarse variety will bind together as the pressure of the shed is sitting on it and it won’t move. Round gravel, on the other hand, will constantly move every time you step on it. The following video will show you the steps involved in making one of these types of foundations.


A gravel pad is easier to make than a concrete one


Get the Best Storage Shed for Your Foundation – A Classic Buildings Shed

Classic Buildings

If you want a storage shed that is going to last a lifetime, then get a Classic Buildings shed. Classic Buildings has a wide selection of better-built sheds for you. Purchasing a high quality, custom crafted shed doesn’t have to cost you a fortune, and you don’t need to wait until you have enough money saved to buy one. Contact Classic Buildings today or visit the location nearest to you and find out how easy it is to rent-to-own your own beautiful wooden shed. We provide financing and most people can even qualify for $0 money down.

Remember, before buying a shed you should be aware of the shed permit requirements of your municipality. Sometimes permit requirements depends on the size of your shed.

Classic Buildings has locations throughout the Midwest, including various Missouri cities (St. Louis, Arnold, Columbia, St. Charles, Rolla, Linn, Springfield, Jefferson City, Kansas City, and Washington Missouri). We are located in Swansea, Illinois and Kansas and deliver throughout the Midwest, and, in some cases, nationwide!

If you would like to take a look at Classic Buildings’ storage sheds, check out our brochure, or visit one of our locations to see our sheds firsthand!


“It was a pleasure working with confident and qualified people. The workmanship and materials are second to none…I would recommend Classic Buildings to anyone who requires a building for storage, recreation or whatever your needs are.” – Mike Dinello


 Read more testimonials here!