How To Build a Concrete Block Shed Foundation Effectively

It is simple and cost-effective to build a shed foundation using concrete blocks. Solid concrete blocks are the best to use because they don’t have any openings in them.

Avoid using cinder blocks, as they will deteriorate over time and cause your shed to settle.

A shed base of concrete blocks is ideal only if the ground isn’t too steeply sloped.

Step 1: Gather Tools & Materials For Concrete Block Foundation

You will need these supplies for crafting a shed base with concrete blocks.

• Solid concrete blocks of 2 and 4-inch thicknesses
• Compactible gravel
• Excavation tools
• Hand tamper
• Long 2x4s
• Mason’s string
• Stakes
• Hammer
• Tape measure
• Spirit Level
• Asphalt shingles
• Construction adhesive

Step 2: Create The Outline Of The Shed Base

1. Clear the construction site of any branches, bushes, or rocks.
2. Drive stakes into the ground at the corners of the foundation, keeping the size at least a foot extra than the actual shed’s footprint.
3. Tie mason’s strings between the stakes to check they are all correctly aligned and readjust as needed.
4. Excavate the soil inside the marked area to a depth of about 4 inches and fill it with compactible gravel.
5. The gravel bed will ensure proper water drainage as the ground freezes and thaws. This increases the life of the foundation.
6. If you want to keep costs low and save on gravel, you can just dig only the specific areas where your will be placing the blocks and fill these patches with gravel.

Step 3: Lay Down Concrete Blocks

1. Lay down concrete blocks at the four corners of the shed and at every six inches along the perimeter.
2. Check that the mason strings and the blocks are flush with each other and make each block level.
3. If there is a slope in the ground, then stack blocks on each other until both ends are at the same height.
4. Use blocks of different thicknesses to get the correct alignment.
5. Lastly, use a long 2×4 and a spirit level to check that the entire line of blocks is level.
6. Add or remove gravel underneath the blocks to make minor adjustments.
7. Use asphalt shingles as shims to fill in any gaps between the blocks.
8. Glue any stacked blocked together using construction adhesive.

Now you can move on to build the floor framing in the next stage of constructing your DIY shed.