Why use a shed base kit
A shed is only as square as the ground under it. A plastic grid base gives you a flat, free-draining floor in an afternoon. There is no concrete to mix and no curing time to wait through. The tiles click together over a weed membrane, then you build straight on top. This range holds 13 Fastfit EcoBase kits from 6x4 to 11x21. Pair one with a plastic shed, metal shed or garden store.
Each grid is moulded from 100% UK recycled plastic. It carries up to 300 tonnes per square metre, so it suits sheds, log cabins and summerhouses. The built-in membrane blocks weeds and lets rain soak away. Cut the tiles to size with a hand saw if your building sits between sizes.
The base is the job people rush, and it shows a year later in a sticking door. We lay a grid kit on a flat, firm sub-base of compacted gravel, never straight onto soft grass. Get it level across the full footprint and the shed goes up square first time. The plastic never rots, so the floor stays true long after a timber frame would sag.
Grid base vs concrete vs paving
| Feature | Plastic grid | Concrete pad | Paving slabs |
|---|---|---|---|
| Fitting time | An afternoon | A day plus curing | A day |
| Drainage | Free-draining | Runs off | Runs off |
| Skill needed | Low | High | Medium |
| Reusable | Yes | No | Sometimes |
| Best for | Most sheds | Heavy cabins | Small stores |
Matt's pick
For a standard 6x4 shed the Fastfit 6x4 kit at £89 is the easy choice. It drops in over gravel and drains well. For a larger building we fit the 9x9 kit at £235. The bigger grid spreads the weight of a full summerhouse.
What size floor kit do I need?
Match the kit to your building footprint, not the ground you have. A 6x4 shed sits on the 6x4 kit. If your shed falls between sizes, buy the next size up and trim the tiles with a saw. Leave the kit flush with the shed edge so water sheds clear.
How to lay a grid base
Mark out the footprint and dig off the turf. Level a bed of compacted gravel across the whole area. Roll out the membrane, then click the tiles together on top. Check it is flat with a spirit level before you build.
What will it cost?
Floor kits here start at £89 for a 6x4 base. The largest 11x21 kit covers a big cabin. Every kit includes free mainland delivery. There is no concrete or tool hire to add.
Shed base questions
What is the best base for a shed?
A firm, level base that drains well is best. A plastic grid kit gives you all three without concrete. It suits most sheds, cabins and summerhouses.
Do I need a base for my shed?
Yes, every shed needs a flat, solid base. Without one the frame twists and the doors stop closing. A grid kit is the quickest way to get one.
Can I put a shed straight on grass?
No, grass moves and holds damp against the timber. The shed soon sits unevenly and the floor rots. Lay a grid base over gravel instead.
How does a plastic grid base work?
The tiles click together into a rigid grid over a membrane. You seat them on gravel for support. The open cells let rain drain straight through.
Can I cut the floor kit to size?
Yes, the tiles cut easily with a hand saw. Trim them to match an odd building footprint. Buy the next size up when you are between sizes.
Will a grid base take a summerhouse?
Yes, each grid holds up to 300 tonnes per square metre. That carries a summerhouse or a log cabin. Lay it on a well-compacted sub-base for heavy buildings.