Garden building site and base preparation guide


Base preparation

The most important part of any base preparation is choosing the most suitable area in your garden.

Firstly consider what you want to use your building for, this may alter the position it will eventually be located.

If an existing concrete, paved or decking area were not available an ideal site would be a fairly level dry lawn or compacted soil.

It is important at this stage to make sure that the proposed siting of the building applies to the current Planning and Building Regulation requirements.

Another consideration to take into account is with the ever increasing wet seasons we seem to be having, it is important that the chosen site does not get to boggy, which could result in making a building liable to. As long as the ground is relatively level (within 6-9 inches) and not subject to bogging the building could quite happily be assembled onto bearers, bricks and blocks. Alternatively you can choose the more permanent approach of a reinforced concrete base, which is ideal if the ground needs building up or lays a little wet. ?

Something else we would always recommend, whether you are choosing a concrete base or not, is pressure treated floor bearers. These will raise the floor of the building off the ground allowing air to circulate, thus keeping the underside of the floor dry and extending the life expectancy of the building, timber doesn't mind getting wet but it doesn't like staying wet. ?

Pressure treated floor bearers

3’’ X 2’’ pressure treated floor bearers are recommended to level the buildng onto an existing or specially laid concrete base, paved patio or decking area to raise the building by approximately 2’’ to allow for air circulation under the floor and to prevent any part of the buildig from having direct ground contact. The bearers usualy run in the shortest dimenson. The floor/josts of the building are laid across and secured to the bearers at 90 degrees to provide a raised, level and supporting base.

Mixture of bricks, blocks & packing

A mixture of losely laid brcks, blocks and packing are compacted into the ground and used to level each floor bearer at 4ft intervals onto an existing soil or lawn site where no base has been specially prepared. The floor josts of the buildng are laid across and secured to the bearers at 90 degrees to provide a raised, level and supporting base.

Perimeter base gravel boards

Pressure treated gravel boards are cut to size and fitted around the perimeter of the building’s floor to disguise the brick/block packing used to level and support the bearers onto a sloping site.

Reinforced concrete base

A 4’’ – 6’’ thick reinforced concrete base is laid to base dimensions of the building. The site will be dug out as required to enable the lowest side of the base to be slightly sunk into the ground and finished just above the existing ground level. All spoils dug out for the base will be removed from site. Additional costing’s are available to quotation for sites which slope more than 9’’.


Pressure treated floor


Mixture of bricks, blocks &


Reinforced concrete


Perimeter base gravel