One of the most common questions we get before a shed delivery is about the ground underneath. What do you need? Does it have to be concrete? Can you just set it on grass? The answer depends on the type of shed, how you plan to use it, and sometimes what your local building code requires.
This article covers the main foundation options, what they are good for, and what you actually need before your shed arrives.
Bare Ground or Grass: Not Recommended
Setting a shed directly on bare ground or grass is technically possible but tends to cause problems over time. Soil shifts, especially with wet and dry cycles. Grass holds moisture against the floor framing or slab, which accelerates rot in wood sheds and can cause rust on metal components. The shed settles unevenly as the ground under it moves.
Most shed manufacturers and installers, including Banner Buildings, recommend against placing a shed directly on unprepared ground. It is the cheapest short-term option and often the most expensive long-term one. If you are going to invest in a quality building, spend a little time on site preparation first.
Gravel Pad: The Most Common Option
A compacted gravel pad is the most common foundation for delivered sheds, and for good reason. It drains well, does not shift significantly, and is far cheaper and easier than a concrete slab. For most residential storage sheds, a gravel pad is the right choice.
For a typical shed foundation, you want crushed stone -- sometimes called crusher run or gravel -- compacted to a depth of four to six inches. Pea gravel is not ideal because it does not compact and will shift under weight. Crushed stone with angular edges locks together when compacted and provides a stable base.
The pad should extend six to twelve inches beyond the shed's footprint on all sides. This helps with drainage and keeps the edges of the floor structure off the soil. The area should be reasonably level before the gravel goes down -- if your site has significant slope, you may need to do some grading first.
For a 12x20 shed, you are looking at a pad roughly 14x22 feet. A local landscape supply company can deliver the material and tell you how many tons you need for the square footage and depth you are working with.
Concrete Slab: Best for Workshops and Garage-Style Sheds
A concrete slab is the most solid foundation option and is worth the extra cost in certain situations. If you are using the shed as a workshop where you will be standing on the floor for long periods, concrete is more comfortable than walking on gravel over a wood subfloor. If you are parking a vehicle inside, concrete handles the weight and oil drips better. If your local building permit requires a permanent foundation, a concrete slab typically satisfies that requirement.
The downside is cost and lead time. Pouring a concrete slab requires forming, grading, and a concrete truck, and it needs several days to cure before the shed can be placed on it. You will also want to coordinate the slab dimensions with your shed dimensions before the pour. A slab that is the wrong size or that was poured with a lip in the wrong place can complicate installation.
If you are thinking about a concrete slab, handle the slab preparation before you schedule shed delivery. We can help you coordinate the timing so the concrete has cured properly before your shed arrives.
Deck Blocks and Concrete Blocks: Used for Leveling
For Banner Buildings' aluminum sheds, delivery includes leveling the building on concrete blocks. The shed arrives on a trailer and is set in place on blocks that are adjusted to keep the structure level even on slightly uneven ground. You do not need a concrete slab for our aluminum sheds -- the block system handles leveling and keeps the floor structure up off the ground.
Concrete or deck blocks are also commonly used under wood skid-style sheds. The blocks sit on prepared ground and the shed's skids or floor frame rests on them. This gets the floor up off direct soil contact and allows for some leveling adjustment. It works well on sites with modest slope where a full gravel pad or slab is not practical.
If your site has significant slope -- more than eight to twelve inches across the shed's footprint -- additional site preparation or a retaining wall may be needed before installation. We will assess the site during the delivery process and let you know if there are any concerns before we unload the building.
Pavers: Decorative but Less Common
Some homeowners use concrete or brick pavers as a shed base. Pavers can look attractive, especially for smaller garden sheds or sheds in visible parts of the yard. The practical downside is that pavers shift over time -- frost heave in cold climates, soil movement in wet conditions -- and once a paver base is uneven, it is more work to re-level than a gravel pad would be.
If you want the aesthetic of pavers, one approach is to use a gravel base with pavers on top for appearance. The gravel does the drainage and stability work, and the pavers give the finished look you want around the perimeter or in front of the door.
What to Do Before Banner Delivers Your Shed
For aluminum shed deliveries, we ask that the site be reasonably level and clear of obstructions. A gravel pad is ideal but not required if the ground is firm and level. We will handle placing and leveling the shed on blocks during the delivery.
For build-on-site wood sheds, site preparation matters more. We will discuss the specific requirements with you when you order, based on the size of the building and your site conditions.
If you are unsure whether your site needs preparation before delivery, call us at 706-568-0500 and describe your situation. We can help you figure out what is needed so the installation goes smoothly.