Garden Base Building Guide

Building the right base for your new garden building is very important. If you do not build the right base for your garden building it can deteriorate.

If the base for your building is not flat and level doors can drop, water can leak into your building and the panels of your building may break. This guide will go through a few simple ways you can ensure you building the correct base.

Things to consider before building a base:

Access: you will need access to all sides of the building during construction so ensure your base is not built too closely to surrounding walls or fencing.

Treatment: You will need to treat wooden garden buildings annually so ensure you have access to all parts of the building so you can apply paint easily.

Natural Light: Make sure the position you have chosen for your building offers enough natural light otherwise you may have to install a different form of lighting in your building.

Electrical Supply: If you are installing your building with plans to add electricity make sure it is in the right position. If you are unsure contact an electrician before building a base for your building.

Planning Permission: If you are unsure about the planning laws in your county contact their office before purchasing a new building. Houses built in protected planning areas may be subject to different rules.


PortabaseThe Waltons Portabase is a time and cost saving base perfect for garden sheds. The Portabase is made from timber and comes in a range of sizes to suit different buildings. You can find the Portabase on product pages under accessories.

A Waltons Portabase is made from timber and features bearers. The Portabase features four spikes on each corner; these spikes can be sunk into the ground offering a stable base for a building. Metal support brackets are also delivered with the Portabase is you are installing it onto a hard surface like a patio or driveway.

You will need to ensure the ground you install your Portabase onto is level and flat otherwise your Portabase will not be level and could cause damage to your building when installed. Always use a spirit level when installing a base to check it is truly level.

Concrete Slab Base

Concrete Slab BaseA Concrete slab base is the most common type of base for a garden building; it is relatively straight forward to build but many people hire reputable builders to install the base. A slab concrete base needs to be installed in advanced to your garden building to ensure it has enough time to set properly before a building is installed on top of it; if the base is not properly set this can lead to condensation within your new garden building.

Tools Required:

1. Choose a position for your shed; ensure there is enough access all around the shed before marking out this space. Using a measuring tape, string and pegs mark out the base so it is the same size as the buildings floor. To check the area is square measure the diagonals too.

2. This concrete base requires 3 inches (7.5cm) of compact hardcore underneath 3 inches (7.5cm) of concrete. You can dig the base down into the ground or have it raised above. If you want to base to be level you will have to excavate the top earth to a 6 inch depth to allow for the concrete. Ensure the dugout base area is level before adding a layer of 3 inch hardcore.

3. You will need to build a framework of timber to support the concrete and keep it in shape while drying. This involves measuring, cutting and fitting the timber into the shape of your base. Check the diagonals of the framework to ensure it is square.

4. You will also need to check the framework and base is completely level before spreading concrete. Use a spirit level to ensure it is 100% level.

5. To mix the concrete you will use one part cement to five parts ballast. If you are using dry mix concrete just add the instructed amount of water.

6. Spread the concrete evenly within the framework; the concrete should be proud of the framework. Once the frame is filled use a straight piece of timber and rest it on the framework. Use a sawing motion to level out the concrete.

7. These steps should result in a smooth, level base. Let the concrete set completely before installing your building on top.

Concrete Paving Slab Base

Concrete Slab Paving BaseConcrete Paving Slabs can be used to build a base for a garden building. Paving slabs are easy to install and if installed properly provide a level, durable base. The ground must be level underneath the paving slabs to ensure the base is level.

Tool Required:

1. Decide where you want to place your building; ensure you have good access to all sides of your building. Using a tape measure, pegs and string measure and mark out the base. This should measure the same as the base of your building. Measure along the diagonals to ensure the base is square.

2. Dig out the topsoil leaving a depth of 2.5 inches (7cm) to accommodate the base. Level this are and check with spirit level. Once level you can remove the pegs.

3. Mix together 1 part cement to 8 parts building sand. Spread this evenly in the base are ensuring it is 4 cm in depth. Rake it and check with a spirit level.

4. Starting from one corner and working outward lay the concrete slabs. Tap the centre of each slab gently with a rubber mallet to set. Use a spirit level on each slab to check the base is level.

5.The complete base should be level and square. Check the diagonals to ensure the base is square. Brush off any excess sand/cement mix.

If you would like any more help choosing the right base for your building, or would like to discuss your building requirements, then please get in touch with our experienced and friendly, sales team. To contact the team either email them on or give them a call on free phone 0800 0142 333.