Preparing a site for a storage building requires careful planning, and is vital in ensuring the long life of your structure. Here’s how to build a foundation for a shed that is both sturdy and allows for proper drainage of moisture.
Do NOT place your shed on cinder blocks. While it is a cheap way to build a foundation, there will be some settling of your shed early on. This will cause your shed to sit unevenly, putting stress on the overall structure. It also is more difficult for us to deliver and place your shed, and the lack of a proper base voids our warranties.
You can use a concrete pad for more permanent placements, however the size of the pad must exactly match the size of your shed floor to ensure proper water drainage. The wall sheathing of your building can then extend just below the top surface of the concrete, to help ensure a watertight seal.
This option however is much more expensive than a crushed stone base, which is our typical recommendation for most customers. It is less permanent, and more easily removable should you ever decide to move the structure in the future. A crushed stone base will also satisfy the requirement for a proper pad to be eligible for our warranty.
A minimum 3-4” crushed stone base that is at least 1 foot larger than your building in both directions is recommended. The space between the stones allows moisture to drain directly into the ground, which is especially helpful in preventing moisture buildup underneath.
The greatest enemy to any shed is moisture. You can probably find evidence of this in your own neighborhood: look for older sheds placed directly on the ground. You should see evidence of rot at the bottom of these sheds, which eventually weakens the overall structural integrity of the structure.
As rain falls from the edge of the roof, it deflects off of the ground and splashes onto the sidewalls of the shed. Over time, this causes the doors and lower siding of these sheds to rot. Once this process starts, it is irreversible, and will eventually require the entire shed be replaced to prevent collapse.
With crushed stone, while there is still some splashback it is significantly lessened, and water will not pool underneath or around the structure and will instead absorb into the ground naturally.
Why do Site Prep?
There are other reasons why site preparation is important:
Uneven foundations may cause your doors and windows to function improperly, or fail to stay open or closed.
Floors too close to wet ground will begin to warp or sag over time.
Proper foundations also keep animals from burrowing underneath your shed or chewing through your floor.