Most online and company guides explain that you must have even ground to install a backyard shed. That means you won’t be able to start your project without completely-level soil to build on.
The problem with this is that no grade is perfect, which means you’ll always deal with some kind of slope or hill. And even if you have flat ground for a wooden shed base, it may be inconvenient for accessing tools and equipment.
Our team has some instructions for how to build a shed foundation on uneven ground. They work for the average backyard that isn’t at 180 degrees across the board. And you can even get these long-lasting shed foundations on a budget.
Also, we have specific tips when laying down shed bases on your particular slope grade.
Shed Foundations for Slight Slopes
Slight slope grades are not as much as issue for building a portable building and you may be able to get away with just leveling out the ground. It’s as simple as shoveling and compacting soil into areas where the elevation dips.
But for hills beyond this threshold, you’ll need a shed foundation that compensates, unless you want to break your back with heavy labor. Money and time can also be a barrier to shaving off a hillside when a different base could solve the issue.
The basic idea for shed bases on slight slopes is to reinforce the elevation loss with a wooden box or a retaining wall. Then, fill the flat ground with gravel (depending on the size of your building) and lay your shed on top.
Your slope backfill solution is the difference-maker for building your shed base on slightly uneven ground. Take a look at how to build shed bases on uneven ground with these options.
How to Build a Shed on Slight Slopes
Gravel Pad in Wooden Box
Constructing a pressure-treated wood box, you can support most backyard sheds on slopes that aren’t too severe. It keeps the portable building standing straight when you’d otherwise have a lop-sided shed.
A gravel base backfill upholds the structure and makes up for the elevation increase. It also has natural drainage so the shed floor doesn’t rust or rot.
Installation Tips for Gravel Pad in a Wooden Box
Place geocell panels inside the wooden box for a more durable shed foundation. Rather than worrying about gravel’s durability failing, you can store concrete and equipment with confidence. Your shed can withstand thousands of pounds of weight with a tougher HDPE foundation.
Gravel Pad with Retaining Wall
A homemade retaining wall functions the same as the wooden box by reinforcing the loss of elevation. Supporting your shed on level ground, the structure adds an aesthetic touch to your backyard that can complement your gazebo and other additions. You can add spikes or rebar to build a retaining wall that doesn’t give way to weather or shed weight.
Installation Tips for Gravel Pad with Retaining Wall
Use a retaining wall when the slope is too steep for a pressure-treated box but too mild for steep grade options. We recommend building the shed a short distance away from the wall so you can push mow and walk around the building’s perimeter.
Shed Foundations for Steep Slopes
On the other hand, you may be stuck with a massive hill that isn’t conducive for minor shed foundation fixes. Gravel boxes and retaining walls are not enough to support the incline unless you paid thousands in backfill and material costs.
Our team instead recommends shed foundations that elevate the shed off the ground rather than fill in the gap. These base solutions have beams, poles, or metal screws that support the structure at various heights.
While the price for a shed foundation drives higher, you will be able to build sheds in areas where other guides have told you it was impossible. And you can do it for a relatively cheaper price than the slight slope solutions offer.
How to Build a Shed on a Steep Slopes
Concrete Piers & Beams
By pouring concrete into sonotubes below the frostline, you can construct sturdy pillars that support the shed. The advantage of making your own concrete foundation with piers is paying less than it would cost to install a concrete pad without sacrificing durability. Although the work is laborious and time-consuming than laying concrete blocks or foundation blocks.
Installation Tips for Concrete Piers & Beams
Do not install concrete piers and beams in the cold weather or winter. Although you may already know this for concrete pads, the same is true for concrete sonotubes. This shed base is frost proof and withstand cracking after you install them but until then, the material is vulnerable to extreme temperature changes.
Posts & Beams
Similar to its concrete sibling, you can dig large enough holes to bury your wooden posts into the ground. Aftewards, we suggest constructing a pressure-treated box that rests on the posts, with the shed on top. You may run into trouble with building codes, but this steep grade method is faster than concrete piers.
Installation Tips for Posts & Beams
Watch your shed over time since wooden posts tend to shift over time. They are less sturdy than concrete piers and beams, so you may have to redo the posts in a couple years so the shed doesn’t collapse suddenly.
Screw piles are a great shed foundation option for your steep, uneven ground if the soil is clay or another hard surface. A contractor will come in and install them through the ground.
Just like other sharp slope options, the shed lays on a box that the metal screws support. This is the most expensive way to build a shed foundation with a hill, but it may be necessary depending on your location.
Installation Tips for Screw Piles
As much as we support DIY shed base installation, our team does not recommend trying to do screw piles by yourself. The kind that laymen people can purchase are not as long as the commercial kind (10-12 feet long) and may not be able to support your shed.
The Shed Base for Any Slope Grade
Slight and steep slopes all require different types of foundations for your shed, whether they be a box, wall, or beams. But no matter the shed foundation, you’ll need gravel, crushed stone, pea gravel, or other gmaterial that the building rests on.
It must support your shed’s weight whether on even or uneven ground.
We believe geocell foundation grids are one of the best shed bases that pair excellently with gravel for an affordable price. It gives your shed the durability of concrete without hiring a specialist and the expensive cost.
To learn more about how you can use geocell for your backyard shed project, call our team at (888)-897-2224. We can assist you with the best shed foundations for uneven ground no matter your type of shed.