Shed foundation guide
Shed foundation types
12 ways to support a shed.
Compare the options, see how the parts fit together and find the base that works for your shed and ground.
By DIYCraft · Updated October 5, 2026
A timber floor on skids over a prepared gravel pad.
Start with the ground and the shed floor
Look at the ground, slope and water first. Then check how your shed floor needs to be supported. Gravel makes a level base, skids hold a timber floor, and a slab can be the floor itself.
A small storage shed
Compare gravel and skids on firm, level ground. Check that your shed floor works with skids.
Read the guide →Sloping ground
Compare concrete piers with the work needed to make a level pad. Use a pier layout made for your floor and ground.
Read the guide →A workshop with a hard floor
Consider a concrete slab. Plan the door height, drainage, equipment loads and wall anchors together.
Read the guide →Ground movement
Will the ground freeze and move?
Surface foundations
Gravel pads, skids, blocks, paving and leveling feet sit near the surface. Wet or freezing ground can move them. Prepare each support well and check for uneven movement over time.
Deeper or protected foundations
Footings may need to reach below ground that freezes, or use a frost-protected design suited to the shed. The needed detail depends on your site and local building rules.
Check local requirements and ground conditions when choosing a footing design. See ICC foundation provisions and HUD’s frost-protected foundation design guide for background.
See the assemblies
Explore every foundation type
Each guide shows what you need and how to build it, with a picture for every step.
01Gravel pad foundation
A level bed of compacted crushed stone for a shed with its own floor supports.
Low–medium relative cost · On-grade
See the build steps
02Concrete block foundation
Solid blocks hold a shed floor above prepared ground.
Low relative cost · On-grade
See the build steps03Skid foundation
Treated timber runners support a framed shed floor on a prepared base.
Low–medium relative cost · On-grade
See the build steps
04Timber-frame foundation
A treated timber perimeter supports a compatible shed floor or base.
Medium relative cost · On-grade
See the build steps
05Concrete pier foundation
Concrete piers carry a raised floor at planned support points.
Medium–high relative cost · Designed depth/protection
See the build steps
06Poured concrete slab foundation
A poured concrete slab gives the shed a hard, continuous floor.
High relative cost · Depends on foundation design
See the build steps
07Pole-barn foundation
Embedded posts carry a shed frame and roof into the ground.
Medium–high relative cost · Depth set by the design
See the build steps
08Deck block foundation
Shaped concrete blocks hold compatible beams above prepared ground.
Low–medium relative cost · On-grade
See the build steps
09Paving slab foundation
Paving makes a firm surface for a compatible small shed.
Medium relative cost · On-grade
See the build steps
10Plastic grid foundation
Plastic grid panels hold their specified fill on a prepared base.
Medium relative cost · On-grade
See the build steps
11Adjustable plastic base
Adjustable plastic feet level a compatible raised shed floor.
Medium relative cost · On-grade
See the build steps
12Adjustable metal base
Metal leveling feet support a compatible raised shed floor.
Medium–high relative cost · On-grade as shown
See the build stepsCompare your options
Which foundation fits your shed?
Compare the ground work, supports and floor. Costs are relative for a small shed. Difficult ground or poor access can add work and cost.
On small screens, scroll the table sideways. Follow a foundation name for its materials and illustrated steps.
| Foundation | Relative cost | Work involved | Sloping ground | Frost protection | Moving it | Floor |
|---|---|---|---|---|---|---|
| Gravel pad foundation | Low–medium | Moderate earthwork | Level platform needed | On-grade | Pad stays; shed may move | Separate floor |
| Concrete block foundation | Low | Moderate | Poor fit | On-grade | Dismantlable | Raised timber floor |
| Skid foundation | Low–medium | Moderate | Level pad needed | On-grade | Possible with moving design | Raised timber floor |
| Timber-frame foundation | Medium | Moderate carpentry | Level base needed | On-grade | Usually dismantled | Infill or designed floor |
| Concrete pier foundation | Medium–high | Excavation and concrete | Good with design | Designed depth/protection | Permanent | Raised timber floor |
| Poured concrete slab foundation | High | Specialist placement | Earthwork/design needed | Depends on foundation design | Permanent | Concrete floor |
| Pole-barn foundation | Medium–high | Specialist layout | Good with design | Depth set by the design | Permanent | Separate gravel or slab |
| Deck block foundation | Low–medium | Moderate | Limited height adjustment | On-grade | Dismantlable | Raised timber floor |
| Paving slab foundation | Medium | Moderate | Level platform needed | On-grade | Units reusable | Paving or kit floor |
| Plastic grid foundation | Medium | Moderate preparation | Level base needed | On-grade | Modules reusable | Separate compatible floor |
| Adjustable plastic base | Medium | Product-dependent | Limited adjustment only | On-grade | Dismantlable | Raised compatible floor |
| Adjustable metal base | Medium–high | Product-dependent | Limited by system | On-grade as shown | Usually dismantlable | Raised timber floor |
Water: gravel and grids let water through. The ground below still needs to drain.
Frost: surface supports can move when wet ground freezes. Concrete alone does not prevent this.
Heavy loads: choose the floor and foundation for what you will store inside.
Plan where water will go
Stone lets water pass through, but the soil below may hold it. Plan a path for rainwater and roof runoff before you dig. A gravel pad in a clay hollow can stay wet.
- Set the floor height and avoid a spot where water often collects.
- Remove grass, roots and soft soil. Fix any weak spots.
- Slope nearby ground so water moves away from the shed.
- Give any drain a clear outlet you can reach for cleaning.
- Keep soil off timber and install the shed anchors.
Common foundation questions
What is the best foundation for a small shed?
A gravel pad with treated skids works for many small sheds with timber floors on firm, fairly level ground. Check that your shed floor is made for skids and plan how you will anchor it.
What is the difference between on-grade and frost-protected foundations?
Surface supports can move when wet ground freezes. Deeper footings or a designed frost-protected system can limit that movement. The right depth and detail depend on your site.
Can I put a shed on grass?
Remove grass, roots and soft topsoil where the foundation will sit. Build the base on firm ground as your shed and foundation plans require.
Does every shed need a concrete slab?
No. Many sheds have a timber floor on skids, blocks or piers. Choose a slab when you need a hard floor, and plan its ground support, drainage, joints and anchors.
Found your foundation? Check the floor.
Match the floor supports and connections to your shed plan before ordering timber.