How to Make the Foundation for a Storage Shed

Concrete foundations are permanent and durable.

Sheds are a household maintenance necessity. Whether you are a gardener or just want to keep the lawns and shrubbery in great shape, you have got to have a place to store the various equipment and tools needed for the job. Instead of building two or three smaller sheds scattered all around the yard, why not just build one, in a central location, big enough to store everything? Of course, every experienced builder knows any structure is only as solid as its foundation. Follow a few steps to build a solid concrete pad foundation.

Things You'll Need

• 25-foot tape measure
• Hammer
• 1-by-2 stakes
• Construction cord
• 8-penny nails
• Pick and shovel or motorized digger
• 2-by-4 boards
• 2-by-4 stakes
• Gravel
• Concrete

Instructions

1. Find a spot in the backyard that is centrally located, usually along the back property line. Check your property line and honor the boundary setbacks. Visit or call the local building inspector’s office to make sure what you want to build is permitted.

2. 

   Digging equipment will make the job much easier.

   Take a close look at the spot where you want to locate it. Check the lay of the land. Make sure it is as flat as possible and the ground around it slopes away from what will be the building foundation. Haul dirt as needed to build up the foundation area. Do not build on slopes or otherwise uneven ground.

3. 

   Staking the foundation site will give you a visual idea of your shed slab.

   Select a location for the first corner and drive a stake. Go to what will be the next corner you have measured off and located and drive that stake. Continue until you have the four corner stakes located, aligned and driven. Tie construction cord around each stake and pull the cord to the next until you have the cord outlining the foundation pad. Make sure your cord is tied off to the outside of the form.

4. Dig out the entire foundation area within the cord boundaries to a depth of 6 inches. Dig a footing trench another 4 inches deeper around the outside lip of the foundation. Drive 2-by-4 stakes at each corner.

5. 

   Build the concrete forms to withstand the load of concrete they will have to hold.

   Go back and drive additional 2-by-4 stakes at 3-foot intervals down all four sides. Nail the form boards to the stakes from the inside. Place them horizontally, beginning at the bottom of the footing trench, and up to flush with the tops of the stakes.

6. Fill the excavated area (but not the footing trench) with 4 inches of foundation-size gravel. Level and smooth roughly. Lay down a plastic vapor barrier on top of the gravel. Mix and pour the concrete yourself or have it delivered and dumped by a concrete company.

7. 

   Concrete will set up if you do not work with it quickly.

   Be ready to move the concrete quickly when it arrives. Use shovels to fill the corners and footings. Stand a 2-by-4 on edge and work it back and forth to smooth the concrete, as you work your way across the foundation. Finish to your desired smoothness and allow it to set up and cure a week or two before erecting the shed on it.

Tips & Warnings

• Be sure of your location before you pour a concrete slab; they are not fun to tear up and relocate.

• Request fiber to be added to your concrete if you live in colder climates; it will strengthen the concrete against cracks and breakage.

References

• Cedarshed: How To Build A Foundation for Gazebos and Sheds
• How To Build A Shed
• A Storage Shed Foundation That Is Easy To Build

Resources

• How to Build a Storage Shed