Why You Shouldn’t Install Your Shed on Shed Foundation Blocks

shed foundation blocks leaning shed

If you’re preparing to have your shed installed, you’re probably wondering whether you need a foundation for a shed and, if so, what kind of foundation is best for your shed. We’ve already outlined our preferred shed foundation in this article. Now we’ll look at a shed foundation type that we don’t recommend: shed foundation blocks.

Installing and leveling your shed on cinder blocks might seem like the easiest solution for shed site preparation. After all, there’s little preparation required if your site is already fairly level. All you need to do is make sure the installer has access to a stack of inexpensive cinder blocks. (Note: leveling the ground for a shed is a better solution)

The problem with using cinder blocks is that it can create problems with your storage building down the road. This is especially true for larger sheds. We’ll now look at the potential problems and reasons not to use shed foundation blocks.

A Shed on Blocks Might Settle Over Time

Installing a shed on blocks might seem like an easy solution but it can cause problems down the road.

One problem is that your shed might begin to settle over time. This is especially true if the ground is soft and unstable.

In the north, the freeze and thaw cycle can be another cause for slight movements that can cause a shed on blocks to settle over time.

shed on foundation blocks

The Doors Might Not Open and Close Properly

A shed that’s not level doesn’t look good and it doesn’t feel good when you step inside. Another potential problem caused by a block foundation is doors that don’t open and close properly.

When a shed settles, it can cause the doors to come out of alignment. This can result in either the doors rubbing the top when your open and close them or not latching properly. You can usually correct this by lifting one corner of the shed until the doors line up again, but that’s not something you want to mess with very often. The best solution is to do it right from the start and place your shed on a solid gravel or concrete foundation.

The Center of the Floor May Not Be Supported

If you choose to install your shed on blocks, there’s a good chance your installer will not take the time to place blocks under the center. That’s because it’s a difficult and time consuming task.

Not having the center of the floor adequately supported can result in a “bouncy” floor that sags over time. This is especially true if you’re getting a larger shed such as a garage that will be storing heavy equipment and vehicles.

The best antidote to a sagging floor is to have your shed installed on a level gravel pad which will have continuous support under the entire floor. You’ll never need to worry about a weak floor with a proper foundation.

shed block foundation floor

Foundation Blocks Do Not Block Grass and Weeds

Grass and weeds growing against the sides of your shed can be a problem because it does not allow the bottom of your shed to dry out after rain. This can cause premature rot and supports the growth of mold and mildew.

It also increases the chances that your shed will become scuffed and bruised when you mow and weed whack around your shed.

shed foundation blocks with grass

Foundation Blocks Do Not Keep Your Shed Clean

If your shed is surrounded by dirt there’s a good chance that the dirt will splash up against the sides of your shed when it rains. The best way to prevent this is with a gravel pad that’s wider than your shed. Learn more about the benefits of a gravel pad that’s 12″ wider than your shed all the way around. 

shed foundation blocks with mud

Foundation Blocks Allow Critters to Move In

If you choose to install your shed on blocks there’s a good chance that you’ll be dealing with unwanted critters at some point down the road. Foundation blocks provide no protection against these types of annoyances.

Although a gravel foundation does not guarantee that you won’t need to deal with this, it will certainly discourage critters from taking up residence under your shed.

skunk shed foundation blocks

Many Builders Discourage the Use of Blocks

Especially in the Northeastern part of the United States, many shed builders discourage their customers from using blocks for several reasons. Installing a shed on blocks often takes more time and it might result in more damage to the shed as discussed in the previous points. Installing a shed on blocks may void the manufacturers warranty. If you’re not sure, check with your builder to find out what foundation they recommend.

The fact is, using blocks under your shed is just one of a number of mistakes to avoid when doing ground preparation for your shed. Check out the rest of our articles for more site prep tips and how-to advice.

What is the Best Shed Foundation?

A Gravel Shed Pad

In most cases, a gravel shed pad is the ideal foundation for a storage shed. It eliminates or reduces the severity of all of the problems discussed above and can increase the life of your shed. It also reduces maintenance issues that might come up in the long run. A gravel shed pad is great for sheds of any size, from a tiny garden tool shed to a gigantic two car garage. Gravel shed foundations are also the easiest kind to install; if you have building experience, you could potentially calculate how much gravel you need and build it yourself. The only requirement is that the shed you’re getting have a wood floor. If you decide to build it yourself, check out our complete guide on how to install a gravel shed pad.

Gravel shed foundation installation available in MD

Other Shed Foundations

Depending on your situation, you might benefit from a concrete foundation or a foundation that utilizes concrete piers. A concrete foundation is a good option if your shed doesn’t come with a wooden floor. If you’re unsure about which foundation is best for you, you can always call one of our site preparation experts to find a solution for your particular situation. You can reach us at (717) 799-7311.

Diagram of a floating concrete foundation for a shed or garage

Concrete Slab

shed foundation piers

Concrete Pier

Shed photo credits: Storage Sheds in VA

14 thoughts on “Why You Shouldn’t Install Your Shed on Shed Foundation Blocks

  1. Pearlean Brooks says:

    Good afternoon. I was just notified that my shed is on the ground. I been in my house for 10 years and I need some advice on how to get my shed off the ground without being to expensive. I have a small shed 8×8 and I don’t want it to cause problems down the road. What would you suggest and are there anyone you know can help me?

  2. Site Preparations LLC says:

    Hi Perlean, if you’re in the Mid-Atlantic US, give us a few more details about your situation through our Contact page and we’ll see if it’s something we can help with!

  3. Ethan Lynn says:

    I have a 14ft x 20ft better built barn tyoe shed im using as a tiny home atm and it on cinder blocks pillars like they laid two blocks then rotated the next two blocks 90% and so on. they are like 3 or 4 coarses high on one ends and maybe on on other end what would u recommend for me too do bc i know one corner has settled about 2 to 4 inches

  4. Site Preparations LLC says:

    Hi Ethan, it’s always more difficult after the building is in place! If you have space next to where the building is now, you could consider installing a gravel foundation as we explain in this article. Once installed, it may be easiest to hire a professional shed mover to transfer the building over.

  5. Bernard Callands says:

    I need to build a shed on a slop and I want to use piers to gain the knowledge for another project down the road. Is a gravel box that much better than a pier installation?

  6. Site Preparations LLC says:

    Hi Bernard, piers are a good option if you’re in a frost-prone area. Gravel pads allow water to drain away, while still keeping critters and weeds from under your building. In fact, you can combine the two foundation types as we did in this job:https://www.siteprep.com/recent-projects/new-jersey/matt-d-gravel-shed-foundation-in-mt-ephraim-nj/
    We have a tutorial on installing gravel shed foundations here: https://www.siteprep.com/how-to-install-a-gravel-shed-foundation/
    If you’re in the Mid-Atlantic US, you can get a quote on professional installation here: https://www.siteprep.com/get-quote/

  7. Shari Torrance says:

    I need to determine what type of foundation would be best for my situation. I’m getting a 15’x8′ plastic she’d. My understanding is that the floor is also plastic. The area where I want my shed is on a slope. Please walk to through the best foundation choice for my situation. Thank you

  8. Site Preparations LLC says:

    Hi Shari, we’d recommend a gravel shed foundation with a treated lumber perimeter, as highlighted on this page: https://www.siteprep.com/gravel-stone-pad/
    We have a guide to whether your shed needs a foundation here: https://www.siteprep.com/do-you-need-a-foundation-for-a-shed/
    We have a guide to building your own shed foundation here: https://www.siteprep.com/how-to-install-a-gravel-shed-foundation/
    You can see more example shed foundations, including some on hillsides here: https://www.siteprep.com/recent-projects/
    Hope that’s helpful!

  9. Jacob says:

    I have a 15×8 plastic shed. My yard is on a slope, so one option was considering a cinder block foundation with gravel inside. What is your opinion?

  10. Daniel says:

    I moved into a house with what looks like a concrete foundation in the back. It is an old house (1910) and we can’t figure out what the the concrete patch is. My guess is that it was once an off-street parking place for the property or some type of patio. How can I tell if this would be a good foundation for an 8×12 skid foundation shed?

  11. Site Preparations LLC says:

    Hi Daniel, if it’s a full concrete slab, it will most likely support a prefab shed. Two things to keep in mind:
    1. Is it level?
    2. Will it drain well? (It’s not ideal to have water pooling around the bottom of your shed if you can help it.)
    Hope that helps!

  12. Cherise says:

    I have a 10’ x 20’ shed built on a slope. It was built on wooden blocks and now the shed, after 20 or so years, has settled on the lower end. Would you recommend tearing up the wooden floor to get access to the frame and lifting and levelling the lower end?

  13. Site Preparations LLC says:

    Hi Cherise,
    By wooden blocks, we assume you’re talking about the wooden runners that support the floor joists of the shed. If that’s the case, it may be easiest to make the repairs from the outside, as you will probably need to lift the lower corner of the shed with a jack or something similar, then add support underneath it. Alternatively, you may be able to have a shed moving company lift the shed off its foundation, install a proper foundation (like a gravel shed foundation), and move the shed back. You may still need to remove parts of the shed floor if the shed runners or joists need repair.
    Hope those ideas are helpful!

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