Base preparation

It is always important to provide a stable, square and level base area for your garden shed or building. If the preparation is not good enough, any construction placed upon it may be in danger of instability and rapid deterioration.

Preparing a base does not need to be a complex affair or expensive. Simple methods such as a set of bearers of concrete or wood, or an area of slabs or solid concrete, can provide the right base preparation. This will enable your new shed or garden building to secure a long life on your chosen site.

Always consider roof overhangs and any protruding parts when calculating the area occupied by your building.

Floor bearers

Bearers made of concrete or treated timber, laid in the opposite direction to the flooring joists, are a typical solution to providing a base. They provide a good air flow to keep the construction timber in a healthy condition. Once the site has been levelled, and any grass or other vegitation has been removed, the simple process of laying out the bearers can be started. Lay the end bearers first and then equally space out the ones in between. Use a spirit level to ensure the tops are all level with each other.

Slab base

As long as the site you propose is not likely to flood, slabs, blocks or of solid concrete can provide the perfect base for your garden shed or building. If you propose to use slabs or blocks, make sure the surface under them is firm and bed down the slabs or blocks into sand, gravel or sand and cement dry mix.

Calculating floor bearers

Selecting the right number of floor bearers will ensure that your new construction has the support it needs. This table indicates the optimum number of bearers for a given floor area. Unless otherwise indicated, sizes are metric, and in all cases approximate. Please contact us if you require more specific dimenions or any other advice about site preparation or installation methods.

Floor Bearers

Slab Base

Building size
(actual floor area)
centre of joists
Number of
floor bearers
required (mm)
4 x 3 1150 x 850 4 290 3 @ 850mm
6 x 4 1750 x 1150 5 290 4 @ 1150mm
7 x 5 2050 x 1450 6 290 4 @ 1450mm
8 x 6 2350 x 1750 7 290 5 @ 1750mm
10 x 6 2950 x 1750 7 290 6 @ 1750mm
10 x 8 2950 x 2350 9 290 6 @ 2350mm
12 x 8 3550 x 2350 9 290 7 @ 2350mm
10 x 10 2950 x 2950 11 290 6 @ 2950mm

Note: All measurements are approximate