What You Need for a Concrete Shed Base: Tools and Materials (UK)
A concrete shed base is a small slab, so the tool list is short: something to dig with, timber for the shuttering, a way to mix the concrete, and a long board to tamp it level. A 2.4 × 1.8 m base 100 mm thick takes 0.48 m³ of concrete, which is 7 bags of cement with 0.33 t of sharp sand and 0.63 t of 20 mm aggregate if you mix it yourself, on 1.05 t of MOT Type 1, with 8.4 m of shuttering board. The shed base materials calculator does your own size.
The tool checklist, stage by stage
1. Set out and dig
| Tool | What it is for | Own or hire |
|---|---|---|
| Tape measure and builder's square | Setting out the base square, and checking the diagonals | Own |
| String line and pegs | Marking the edges | Own |
| Spade and shovel | Digging out turf and soil to depth | Own |
| Wheelbarrow | Moving soil, MOT and concrete | Own or borrow |
| Hand tamper, or a plate compactor | Compacting the MOT sub-base | Own a tamper, hire a plate for bigger bases |
2. Shuttering
| Tool | What it is for | Own or hire |
|---|---|---|
| Hand saw or circular saw | Cutting the shuttering boards and pegs | Own |
| Club hammer | Driving the pegs | Own |
| Drill/driver and screws | Fixing the boards to the pegs | Own |
| Spirit level | Setting the top of the shuttering level all round | Own |
3. Mix and pour
| Tool | What it is for | Own or hire |
|---|---|---|
| Cement mixer, or a mixing board and shovel | Mixing the concrete: a mixer makes a big base much easier | Hire a mixer |
| Buckets | Measuring the mix by volume, so every batch is the same | Own |
| Tamping beam | A straight timber longer than the base is wide, worked across the shuttering to level and compact | Own |
4. Finish and cure
| Tool | What it is for | Own or hire |
|---|---|---|
| Float | Smoothing the surface once it has stiffened | Own |
| Polythene sheeting | Covering the base to keep it damp, and off rain and frost | Own |
| Watering can | Keeping the concrete damp in warm weather | Own |
Safety kit
- Waterproof gloves and wellington boots. Wet cement is alkaline and can burn the skin, so wash any splashes off straight away.
- Safety glasses when you tip cement and when you mix.
- A dust mask when you open and pour bags of cement.
- Lift 25 kg bags with your legs, and use the wheelbarrow rather than carrying them.
- Check for buried services before you dig, using the free LSBUD service.
Materials for other shed sizes
100 mm of concrete mixed 1:2:4, on 100 mm of MOT Type 1, with 10% extra. A 3.6 × 2.4 m base takes 13 bags of cement and 0.95 m³ of concrete, which is a lot of batches to mix by hand, so hire a mixer or price a small ready-mix load.
| Shed base | Concrete | Cement (25 kg) | MOT Type 1 | Shuttering |
|---|---|---|---|---|
| 1.8 × 1.2 m | 0.24 m³ | 4 bags | 0.52 t | 6.0 m |
| 2.4 × 1.8 m | 0.48 m³ | 7 bags | 1.05 t | 8.4 m |
| 3.0 × 2.4 m | 0.79 m³ | 11 bags | 1.74 t | 10.8 m |
| 3.6 × 2.4 m | 0.95 m³ | 13 bags | 2.09 t | 12.0 m |
See the shed base materials list for how each number is worked out, the common mistakes when laying a concrete base, and the decking, fencing and sheds planner. Estimates only: check the shed maker's instructions for the base size.
Frequently asked questions
What tools do I need to lay a concrete shed base?
A tape measure, builder's square, string line and pegs, a spade and shovel, a wheelbarrow, a tamper or plate compactor, a saw, a club hammer, a spirit level, a cement mixer or mixing board, buckets, a tamping beam, a float and polythene sheeting.
How much concrete for a 2.4 x 1.8 m shed base?
0.48 m³ at 100 mm thick with 10% extra. Mixed 1:2:4, that is 7 bags of cement, 0.33 t of sharp sand and 0.63 t of 20 mm aggregate.
Do I need a cement mixer for a shed base?
For a small base you can mix on a board, but 7 bags of cement plus the sand and aggregate is a lot of shovelling. Hiring a mixer for the day keeps every batch the same and saves your back.
What is a tamping beam?
A straight, stiff length of timber, a little longer than the base is wide. Two people lift and drop it along the shuttering in a sawing motion, which levels the concrete and works out air.
More guides
Tools & materials for this project
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Estimates only. Quantities depend on your materials, site and supplier. Confirm important numbers before you order, and check the Building Regulations and any planning rules for anything structural or close to a boundary.
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