01Most adaptable
Gravel pad
A broadly useful starting point for a light wood shed on a site that can be excavated, leveled, and drained.
Watch for
The pad is only as dependable as its base preparation, edge retention, compaction, and drainage plan.
Guide 01 / site before structure
The foundation is the first shed decision.
Choose a support direction after you understand water, ground, frost, access, and local rules - not after a lumber list is already in the truck.
Water first
Trace runoff and drainage.
Level second
Prepare stable bearing ground.
Confirm locally
Resolve the final support system.
Start here
Read the site before choosing the foundation.
This is a decision guide, not an engineered detail. Local building officials and an appropriate design professional determine permanent support, anchoring, frost requirements, and dimensions.
Run the site checkFoundation options
Choose the system that matches the risk.
02Movable wood shed
Skids
A possible choice where the selected system and site conditions support it.
Watch for
Skids do not fix poor drainage, soft soil, or frost movement. Confirm treatment category and support pattern locally.
03Small, simple support
Concrete blocks
A limited support approach on a well-drained, level site where local requirements allow it.
Watch for
Do not use blocks as a substitute for a level bearing surface, a designed support layout, or frost-depth requirements.
04High consequence sites
Piers or footings
Consider them on sites with frost, slopes, heavy loads, difficult drainage, or permanent point-support needs.
Watch for
Depth, diameter, reinforcement, uplift connections, and spacing are site and jurisdiction decisions, not universal DIY dimensions.
Five checks before excavation
Make these calls in order.
If any answer is uncertain, pause before buying foundation materials. The cheapest time to resolve water, soil, or permit questions is before the floor is framed.
- 01
Site rules
Confirm permits, setbacks, zoning, utility locations, and whether your jurisdiction treats the shed as an exempt or permitted structure.
- 02
Water path
Walk the site after rain. Identify where roof and surface water arrive, where they leave, and whether the proposed pad sits in that path.
- 03
Ground condition
Identify organic topsoil, soft fill, standing water, and visible settlement. These are reasons to stop and investigate before ordering materials.
- 04
Finished floor
Set the intended floor elevation before excavation so finished grade, drainage, door threshold, and access all work together.
- 05
Reference match
Use a Planning Reference to define footprint and siting questions; have the final foundation type, materials, and support layout confirmed locally.
Drainage is a system
Keep surface water moving away from the shed.
Plan grade and roof runoff together. The EPA's water-management guidance emphasizes positive drainage away from foundations; exact slopes, drainage features, and code requirements vary by site and jurisdiction.
A field-note habit
Visit the proposed pad during or just after a heavy rain. Photograph water paths, low spots, and soft areas. Those observations are more useful to a local official or contractor than a guess made from a dry lawn.
Never route roof runoff onto a neighbor's property or into a place prohibited by local rules.
Common foundation mistakes
Do not build a problem into the first day.
- Starting with a perfectly square floor layout on ground that has not been leveled and compacted.
- Letting roof runoff or uphill surface water terminate at the shed perimeter.
- Burying untreated framing, or choosing treated wood without checking its use category for the exposure.
- Using a block, pier, or skid pattern copied from a different shed size or soil condition.
- Treating local frost, setback, anchoring, wind, snow, or permit rules as optional details.
Future structural guides will publish only with approved local-source data.