Choosing the Best Shed Base for Your New Shed

Question: What is the best shed base for my shed?

When it comes to building a shed, one often overlooked but crucial element is the shed base. The right foundation not only provides stability and durability but also ensures the longevity of your shed. With various options available, it can be challenging to determine what the best shed base is for your needs. In this post, we’ll explore three different shed base options and help you make an informed decision.

Wood Shed Base (on grass):

At SquareShed, we believe the best shed base is our standard wood shed base. Wood shed bases are solid, can support a lot of weight, look good, and can last for a very long time. Not all wood shed bases are the same, though. The size of the floor joist boards, the method for leveling the shed, and the subfloor material are all very important factors in determining the quality of the wood shed base. Our go-to materials are pressure treated 2×6 floor joists, Advantech subflooring, and TuffBlock footings for leveling the shed. Each of these are discussed further in separate posts.

Building a wood base over grass has its pros and cons, but generally speaking it’s a good idea.

Pros

• Efficient
  • A wood base can be installed over grass in a matter of hours.
• Cost effective
  • Compared to a cement slab or gravel, nothing comes close to building right on the grass.
• Adjustable
  • If there is settling over time (which does happen), adjustments can be made fairly simply.
• Air flow
  • Because the underside of the shed is open, air can circulate underneath the shed. This is great because it helps to reduce moisture and mold on the floor joists and subfloor, keeping things dry and safe.

Cons

• Animals
  • Inevitably, animals or critters will try to make a home under the shed. There are certainly ways to prevent that, though. Many shed owners will install landscaping, chicken wire, or other materials in order to block the open space between the shed base and the ground.
• Large gaps
  • If your yard has a significant slope, one side of the shed will sit up higher than the other. This is not bad structurally, but can look a little strange at first. Good landscaping around the shed can help with that as well!
  • Many shed companies will only deliver or set a shed on your property if the ground is within a certain level. With us, that’s not the case… we can work on almost any terrain!

Wood Shed Base (on gravel):

This method is essentially the same as the previous method of building a wood shed base on the grass – but this time a gravel pad is installed beforehand. The advantages and disadvantages of the selected floor joists and subfloor material would apply here as well.

To build a wood shed base on a gravel pad, it’s a pretty simple process. A bunch of gravel is hauled to the build site and poured and compacted into place. Generally, the pad is built so that it is at least 12” longer on all sides than the shed will be. So for a 10’x12’ shed, you would want the gravel base to be at least 12’x14’ in size (or bigger).

Pros

• Easier to level the wood base
  • Once the gravel pad is level, installing a level wood base is even easier.
• Shed is even/lower to the ground
  • Because the gravel pad is built up to the same height all around, the shed will not have any high or low spots.
• Easier to add landscaping later
  • The shed sits lower to the ground and is even to the gravel all the way around, which makes landscaping or adding pest-control fencing easier.

Cons

• Added cost
  • Gravel pad costs vary. While not as costly as a cement slab, they are significantly more than building on the grass.
• Added build time
  • Depending on the size, a gravel pad will add a full day to the build time. It also adds more complexity to the scheduling, because the pad will have to be 100% ready before the shed construction can begin.
  • SquareShed does not install gravel pads ourselves, but we can help you find a reliable installer if you so choose.
• Still prone to animals
  • While the gap between the gravel and the shed base is minimal, certain animals can still sneak their way underneath.

Cement Slab:

Concrete slabs are a popular choice for shed bases due to their durability and stability. A well-constructed concrete slab provides a solid foundation that can withstand heavy loads and withstand the test of time. However, it’s essential to consider the cost and effort involved in pouring and curing concrete.

Pros:

• Excellent stability and durability
  • Cement floors are obviously very strong and can hold up for a long time with the proper care.
• Better animal resistance
  • Unlike the wood base, with a cement slab there is nowhere for animals to get under. So there is no need to add any fence or landscaping to keep critters away.
• Keeps shed lower to ground
  • Because the slab usually sits just above the grass level, a ramp is probably not necessary. Ramps are easy to add to a wood shed base, though, if you go that route instead.

Cons:

• Cost/labor
  • The main downfall of cement slabs for a shed base is cost. The cost to install a slab can add a significant amount to the entire project.
  • In addition, finding labor to do a job of this nature can be challenging. Many concrete companies do not even want to take on small odd jobs like a shed base. 
  • We don’t install cement slabs ourselves, but will assist you in finding a subcontractor for the job. The problem is that reliable subcontractors are very difficult to find right now!
• Time
  • Cement slabs take time to pour, and time to cure after that. This adds to the overall build time, and requires more planning in advance.
• Cracking
  • Over time, as the slab settles (which does happen), cracking can occur.
  • While it’s generally not a big deal structurally, it can look bad. Other times, the slab can settle so much that it does become and issue structurally.
• Slab quality
  • Whenever we build a shed on a slab, we warn customers that we can only make build the shed as square and as level as the slab is.
  • Depending on who installed the slab, it’s not uncommon for the slab to be unlevel or out of square.
  • Most of the time we can still build and make it work, but we are somewhat limited by the quality of the slab.
• No adjustments
  • Some settling of your shed foundation is inevitable over a long enough time frame. Unlike the wood shed base, there is no great way to adjust the foundation without a costly repair.

Conclusion:

So what is the best shed base for your shed? It depends!

You now know the pros and cons to a few of the different options. We believe that a wood foundation build on the grass is the best shed base, because of its versatility, efficiency, and cost. Next would be the wood foundation on a gravel pad, followed by a cement slab last.

That being said, we have built and will build sheds on gravel pads and on cement slabs. We do not provide the gravel or the cement in-house, though we can try to help make recommendations on who to do that work if you choose that route.

We hope you now have a better understanding of the different types of shed bases and what the best shed base is for you!