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An 8×8 shed foundation is a level gravel pad with concrete blocks, stringers, or pavers, or a poured slab sized to the floor frame.
For the full breakdown, see our best 8×8 Plastic Shed guide.
The right time to figure out how to build an 8×8 shed foundation is before you order the shed, because the base decides whether the floor stays square or twists within the first year. A proper foundation keeps wood off wet ground, spreads the weight evenly, and gives you a level surface to bolt the floor frame to. The specs below come straight from an 8×8 shed manual and follow standard US building practice.
Three Foundation Options for an 8×8 Shed
An 8×8 shed foundation comes down to three proven methods: a poured concrete slab, a gravel base with pressure-treated 4×4 stringers, or a gravel base with patio pavers. A concrete deck-block base is a fourth, faster option that suits smaller floor frames like this one.
| Foundation Type | Materials for an 8×8 Shed | Best For |
|---|---|---|
| Concrete slab | 1.2 cu yd of concrete; pad 91″ x 96″ and 6″ deep | Permanent, heavy, or cold-climate sheds |
| Gravel + 4×4 stringers | 1.5 cu yd of gravel; 5 treated 4x4s, 8 ft long | Fast build under a wood floor |
| Gravel + patio pavers | 1.5 cu yd of gravel; 25 pavers 8″ x 8″ or larger | Quick base with no concrete work |
| Concrete deck blocks | 8 blocks plus pea gravel | Small floor frames, DIY-friendly |
All gravel options need the hole dug at least 6 inches deep and 6 inches wider than the floor frame on each side. Site choice matters just as much: pick a spot that is close to level, does not collect water, and leaves about 3 feet of clearance around the shed. Some builders extend the pad 12 inches beyond the footprint on each side so runoff drops clear of the walls. If you are weighing a DIY build against a ready-made building, our tested 8×8 plastic shed roundup covers pre-built models that sit on the same kind of level base.
Build an 8×8 Shed Foundation on Gravel and Blocks
Concrete deck blocks on pea gravel is the fastest option for an 8×8 footprint, and Lowe’s shed foundation guide uses the same approach. The blocks lift the floor frame off the ground while the gravel underneath keeps water moving away. This suits sheds that arrive without a floor; a model with a built-in floor needs support along the full perimeter instead.
- Lay out the floor size with stakes and string so the footprint is clearly marked.
- Dig a shallow pad at each block location and add a layer of pea gravel for drainage.
- Set concrete blocks 12 inches from each corner of the floor frame, adding mid-span blocks on longer runs for larger sheds.
- Level every block by adding or removing pea gravel until all tops sit