Garden Shed Base: Why You Need One and How to Build It

Garden Shed Base: Why You Need One and How to Build It


A garden shed base serves a few purposes. Without one, the shed won’t last. The base is needed to support the weight of the shed, to level the ground and to allow for air circulation. You also need to work out where you are going to build your base in the garden.

You won’t achieve all three objectives by laying down some planks of wood to erect a shed on as that won’t give it nearly enough support. In addition, while the ground needs to be prepared for a base, it also needs to be elevated slightly above ground level to allow for rainwater runoff, otherwise, water damage could become problematic. Sheds will shift when they’re sitting too close or directly on the surface of soil or grass because as the ground gets wet, the shed will slope and slant. The purpose of the base is to provide a consistent level base that doesn’t change with ground conditions because the base keeps it off the ground surface.

Types of Bases

There are three materials you can use to build a garden shed base. Wood, concrete and plastic.

Concrete Garden Shed Bases

Concrete includes using paving slabs to cover an area for the shed to be built on. Laying these takes the longest but it does provide the most stable and longest lasting secure base for your shed.

To build a garden shed base using concrete or paving slabs, you’re going to need sand and aggregate to lay on the ground first. If you’re using paving slabs, you’ll need to account for the depth of the slabs and adjust the depth the ground is prepared for. Most will need the turf removed to a depth of 100mm, then a layer of aggregate spread and levelled, then another layer of sand around 30mm thick spread and levelled before laying the slabs.

Using concrete or paving slabs as the base for garden sheds is time-consuming and messy. If you aren’t a DIYer or aren’t comfortable working with construction materials, it’s probably best to hire out the laying of a concrete shed base to a local contractor, either a handyman service or a local landscaping company.

Wooden Shed Bases

A wooden shed base is easier to install but it’s only suitable for smaller sized sheds. A kit will include pressure treated timber strips and galvanised steel brackets. It’s best to put the components together where you’ll be building your shed because it’s heavy once constructed due to the number of timber planks used. A rectangle is formed around the outer of the base, then the inside fitted with bearers to provide additional support. If you are using a wooden shed base, you are going to need level ground. This can require additional prep work before you can install the wooden base. If your garden is unlevel, it may be easier to install a concrete base as that’s easier to level rather than having to make alterations to the ground to make your wood base sit level.

Once the framework is ready, steel ground pegs/spikes are then used at each corner of the shed base to secure it into the ground.

Plastic Garden Shed Bases

Plastic garden shed base kits are made of tiles of interlocking grids that secure together but require a pre-base of builder’s sand and pea gravel to level the ground first and fill the spaces within the grid once laid. These are the easiest to install as it’s only joining tiles together, locking them in place with pegs supplied then filling the spaces with pea gravel for added strength. The trickier part is getting the ground level.

The strongest and longest lasting is to use a concrete base or a base built with paving slabs. However, that’s only if you know you want a permanent garden shed installation. If you think you’ll move home and want to take the shed with you, then a wood or plastic garden shed base are options that let you take your shed down, pack the base up and move it to your new home.