The base is the least exciting part of buying a shed, and the most important. Put a shed on soft, uneven ground and the frame twists, the doors stick and the floor rots from below. Put it on a good base and even a budget shed will last for years.
The four main options
| Base | Cost | Effort | Best for |
|---|---|---|---|
| Concrete slab | Highest Hardcore, concrete and timber shuttering | High A weekend, or a day for a builder | Big sheds, workshops, log cabins Permanent and rock solid |
| Paving slabs | Medium Slabs, sand, cement and hardcore | Medium A day for most DIYers | Most sheds and summerhouses Can be lifted if you move |
| Plastic grid kit | Lowest Kits from around £40 for a 6×4 | Low An afternoon, no mixing | Sheds up to about 10×8 Free-draining and lightweight |
| Timber or steel frame | Low Kits from around £50-£90 | Low to medium Needs careful levelling | Sloping or awkward ground Keeps the floor off damp soil |
Concrete: the gold standard
A concrete slab, around 75-100mm thick on a compacted hardcore sub-base, is as solid as it gets. It’s the right choice for heavy buildings like log cabins and workshops. The downsides are cost, effort and permanence. Once it’s down, it’s down.
Paving slabs: the sensible middle ground
Slabs laid on a sand and cement bed over compacted hardcore make a great base for most sheds and summerhouses. It’s very doable as a DIY job and you can lift the slabs later if you move the shed.
Plastic grid bases: quick and easy
Interlocking plastic grids clip together over a weed membrane and get filled with gravel. They’re light, cheap, drain well and you can lay one in an afternoon with no concrete. For most sheds up to 10×8 they’re our go-to.
Best for a 6×4
6 ft x 4ft Plastic Grid Shed Base Kit with Weed Membrane, Gravel Grid
A complete kit with membrane included, sized for a 6×4 shed. No mixing, no mess.
- Kit sized for 6×4
- Weed membrane included
- Lays in an afternoon
Best for an 8×6
6ft x 8ft Plastic Grid Shed Base Kit with Weed Membrane, Garden Path
The same simple system sized for the UK’s most popular shed. Fill with gravel and you’re done.
- Sized for 8×6
- Free-draining
- Lightweight
Best for a 10×8
10 ft x 8ft Plastic Grid Shed Base Kit with Weed Membrane, Garden
A bigger kit for larger sheds and small summerhouses.
- Sized for 10×8
- Membrane included
- Strong grid design
Timber frame bases
A pressure-treated timber frame on adjustable feet or blocks is handy on sloping ground, where digging a level pad would be a big job. Make sure it’s properly treated and keep the bearers off wet soil.
Best timber base
Arbor Garden Solutions Wooden shed bases 8×6 (W-236cm x D-182cm) (2×4
A ready-made timber base frame for an 8×6. Good for slightly uneven ground.
- Treated timber
- Raises shed off the ground
- Quick to fit
Best steel frame
Gardebruk 6x8ft Greenhouse Base Frame, Steel Shed Foundation Kit
A galvanised steel foundation frame that won’t rot. Popular under greenhouses and metal sheds.
- Rot-proof steel
- Sized for 6×8
- Easy to level
Getting it level
- Mark out the base about 5-10cm bigger than the shed on every side.
- Dig out the turf and topsoil, then compact the ground.
- Add a layer of hardcore or MOT Type 1 and compact it again.
- Lay your base and check it with a spirit level in every direction.
- Leave a slight fall away from the door so water drains off.
Tip: Keep the base just inside the shed’s walls, not sticking out past them. Otherwise rain lands on the base and runs straight under your shed.
Browse all shed bases, or read our size guide if you’re still choosing the shed.
