If you're a keen amateur builder, you'll know that working with concrete can be a bit of a guessing game

How to Lay a Concrete Shed Base

If you're planning to build a shed in your garden or backyard, it's essential to have a sturdy and level base to support it. A concrete shed base is a popular choice due to its durability and longevity. However, laying a concrete shed base can be a challenging task, especially if you're not familiar with the process. 

We’ll guide you through the steps of how to lay a concrete shed base, from planning and preparation to pouring and finishing. By following these instructions, you'll have a solid and reliable base for your shed that will last for years to come.

Gather your tools and materials

Before you start laying your shed base concrete, make sure you have everything you need. Here's a list of essential tools and materials for your concrete shed base project:

  • Measuring tape

  • Pegs and string

  • Spade or shovel

  • Spirit level

  • Wooden battens or boards

  • Timber pegs

  • Ballast (sharp sand and gravel mix)

  • Cement

  • Water

  • Wheelbarrow or cement mixer

  • Trowel or float

Now that you've got your materials and tools sorted, it's time to start the groundwork.

Marking out and excavating the area

Before you start laying your concrete shed base, you need to decide where you want your shed to go. Choose a location that's level and free from waterlogging with good access. Once you've chosen the perfect spot, follow these steps.

Measure and mark out the area

Using your measuring tape, pegs and string, mark out the exact size of your shed base. Ensure you include an additional 5cm on each side for the formwork.

Excavate the area

With your spade or shovel, start digging out the marked area. You'll need to dig down about 15cm to create a solid and level foundation for your shed base concrete.

Check for level

Use your spirit level to ensure the excavated area is level. Adjust the ground as necessary.

Install a sub-base

To provide extra stability and drainage, add a 5cm layer of compacted hardcore or crushed stone in the excavated area.

Building the formwork for your concrete shed base

The formwork is the wooden framework that will hold the wet concrete in place as it dries. Follow these simple steps to create your formwork.

Cut your wooden battens or boards to size

Measure and cut your timber to match the dimensions of your shed base, plus the additional 5cm on each side.

Fix the timber pegs

Hammer timber pegs into the ground around the excavated area at 1m intervals.

Attach the formwork

Place the wooden battens or boards against the pegs, securing them with screws or nails.


Now it's time to pour the concrete for your shed base.

You can explore our ready mix concrete options for shed bases - Basecrete and Basecrete extra, which will be delivered to your door on the required day.

Pour the concrete

Slowly pour the mixed concrete into the formwork, spreading it evenly across the entire area.

Level the concrete

Using a straight-edged piece of timber, level the concrete by dragging it across the top of the formwork.

Smooth the surface

With a trowel or float, smooth the surface of the concrete, ensuring it's even and free of any imperfections.

Tidy the edges

Use a spade or trowel to neaten the edges of your shed base, ensuring they're straight and smooth.

Check for level

Using your spirit level, double-check that the surface of your concrete shed base is level. Make any necessary adjustments while the concrete is still workable.

Allow the concrete to set

Leave the concrete to dry and harden for at least 24 hours before removing the formwork. For the best results, let the concrete cure for up to a week before placing any heavy loads on it.

Allow the concrete to cure

Give your concrete shed base ample time to cure fully. This usually takes around 28 days but can vary depending on weather conditions and the specific mix used.

Finishing touches

With your concrete shed base set and ready, it's time for the finishing touches.

Remove the formwork

Carefully remove the wooden battens or boards from around the base.

Install your shed

With your concrete shed base complete, it's time to assemble and install your garden shed according to the manufacturer's instructions.


Congratulations! You now know how to lay a concrete shed base that will provide a solid, level and durable foundation for your garden shed. 

With the right preparation, tools, and materials, building a shed base from concrete is a project that's well within the reach of any keen gardener or DIY enthusiast.

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