When homeowners run out of space in their homes and garages, they often turn to a shed for more flexibility. But, these outdoor structures need a sturdy, level base that sheds water for longevity’s sake. When a pair of homeowners needed a gravel foundation for their new shed purchase, mason Mark McCullough was happy to help out.
How to Make a Gravel Shed Foundation
- Start by checking your local regulations regarding offsets or setbacks. In most cases, sheds should be at least 5 feet from the neighbors’ yards. This is important as installing a gravel base in the wrong spot will require a lot of work to remedy.
- When installing a gravel base, it’s important to over dig the area. Consider the shed’s footprint and add one foot in each direction. This will allow for the shed frame and gravel for additional stability as well as water runoff.
- Dig 4 to 6 inches below grade. Compact the existing soil with a plate compactor. Sprinkle the surface with water and continue compacting until the base is solid.
- Install a layer of landscape fabric over the soil. This will help prevent weeds and keep the graven from sinking into the soil over time.
- With the shed’s measurements in mind, cut the frame. For an 8×6 shed, cut two landscape timbers to 9 feet and two to 7 feet. Install them in the ground and connect them using landscape timbers driven through the longer boards and into the ends of the shorter boards.
- Use a level to adjust the frame. Add handfuls of gravel wherever necessary to create a level frame.
- Pour the gravel into the frame. Spread it with the steel rake to fill the entire foundation. Use a screed board to level the top of the foundation, filling in low areas as needed.
- Use tampers to tamp the gravel into the place. Spray the surface with the garden hose to dampen the gravel for better compaction. Take note of any low areas and fill them in as needed.
- Rake the surface with the steel rake to remove any large stones that compact the way the shed sits on the surface.
- Once the shed is installed, consider mulching around the shed to prevent splashing and create a more finished look.
Resources
Shed: Tuff Shed – Custom Premier Tall Ranch 8’x6’
Before building a shed base, check city setback requirements to find the distance the shed must be away from property lines and the house.
Use a tape measure and flags or spray paint to measure and mark the shed base’s placement. Using shovels and a wheelbarrow, dig out the base area about 4-6″ deep. Mark used a sledgehammer to break up some concrete and rocks that were in the way. Compact the soil with hand tampers or rent a plate compactor from a local tool rental company. Use a hose to spray water in the area to help with compaction. Heavy-duty landscape fabric was added to separate the soil from the gravel.
The wood frame was made from 4×6 ground contact rated pressure treated wood. Lumber can be cut to size by using a circular saw with a wood blade. Secure the frame by using a drill and 8” structural wood screws. Use a speed square to keep the corners at a 90-degree angle. Use a level to make sure the frame is level.
Add crushed gravel and spread out with metal rakes and shovels. About 1 ton of gravel was used for this project. A 2×4 was used to level out the gravel by laying it across the frame and shimmying it back and forth across the base. Repeat the process for the length and width. Hand tampers and water were used to compact the gravel. Use a fine metal rake to give the gravel one more once over to get rid of any larger rocks that may be at the top.
Extra assistance provided by Motor City Grounds Crew.
Materials
Tools
You may want to rent a plate compactor at Home Depot.
