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Introduction

Building a shed may seem like a daunting task to a DIY novice. Provide a level, sound, sturdy base and the rest should be simple. Building the base for a garden building is an easy task for a single person to complete. However we recommend an extra person is on site during the construction of the shed to help with lifting and placing roof and wall panels.

Planning permission is normally not required for a prefabricated garden building, however, if you live in a conservation area or the building could intrude on a neighbours garden, you may wish to check with neighbours or local council prior to construction.

Planning

Consider the optimum site for the your garden building in terms of:

• General access (for delivery of garden building, access to all sides for maintenance and applying wood treatments etc.)
• Surrounding area conditions (Foliage, young trees that may grow in future etc.)
• Natural light (a light area is best of the building is to be used as a workshop for example)
• View from the planned area (for summerhouses etc.)
• Do you intend to run an electrical supply to the building and does it give any implications?

Methods

It is crucial to provide a level and dry foundation. It is unfeasible to assemble a shed on an unsound base, otherwise screw holes connecting the wall panels will not line up. For larger buildings especially where the shed is to be used as a workshop a full concrete base is best. However, generally there are two types of base suitable for a garden building, consider either:

• A Concrete Base
• A Paving Slab Base

Concrete Base Method

Tools Required:

• Pegs and string
• Building sand
• Standard cement
• Timber for base formwork
• Tape measure
• Spade Sweeping brush

Step 1:

Decide where to position the shed in an optimal space, allow enough distance from hedges or fences for easy access to all sides. Using pegs and string to mark out the base 2 inch (5 cm) larger than the area of the building on each side. Finally, measure diagonals to ensure the area is square.

Step 2:

A concrete base requires 3 inch (7.5 cm) of compacted hardcore underneath the 3 inch (7.5 cm) concrete layer. The base can be level with the ground or raised above it. If it is to be level excavate the top earth to 6 inch (15 cm) to allow for the hardcore layer and 3 inch (7.5 cm) thickness of concrete.

Level the area with a rake and spade and remove the pegs.

Step 3:

Set up levelled formwork. This involves measuring, cutting and fitting timber, to the shape of the base in order to contain the concrete (as shown in the diagram).

Check diagonals to ensure the formwork is square. And also ensure the formwork is level, as this will determine whethery your base is 100% level.

Next, spread a layer of well compacted hardcore and cover with a liberal amount of sand.

Step 4:

Next, mix concrete using one part cement to five parts ballast or use bags of dry-mixed concrete to which you just add water. Small amounts of water should be added at a time and mixed into the concrete mix to ensure excessive amounts are not added making the cement sloppy, as the concrete should be kept on the dry side.

Spread the concrete evenly and slightly proud of the formwork. This can be then levelled off with a long straight edge of timber resting on the formwork using a sawing motion slowly (as shown below) over the entire surface of the freshly laid concrete.