Base works information for Garden Buildings

(These Plans may change without notice please confirm with The Shed Project before using.)


We require a firm surface, which is level to a tolerance of +12mm (½”). An unlevel or oversize base can adversely affect your building. Typical problems can include deflecting floor, binding door, cracked glass and water leakage.

If you have paid to have your building erected, this is carried out at the time of delivery so please prepare the base before our arrival.

The timber floor is included with all kit-sets.

It is the customer’s responsibility to supply the foundations whether it is concrete, pavers or 100 x 75 H4 Bearers.

Floor Bearers (Optional foundation):
100 x 75/ H4 bearers can be ordered separately with your kitset.
The top 50mm of vegetation is removed and fine coarse metal is used to support the bearers.
The bearers are laid at right angles to the floor joists and level. The Bearers must not protrude outside the sides or ends of the building. A foundation specification is supplied with each building.

When setting out allow a clearance of 300mm (12″) all round to provide access for erection and maintenance.

Buildings are constructed to metric sizes, i.e. the correct size for an 8′ x 6′ shed is 2.4m x 1.8m, not    8′ x 6′. Do not make the base larger than the shed. This is because heavy rain will bounce off an oversize base, causing saturation of the lower timbers.

To accommodate a Garden Room ordered with verandah and deck add .700mm to the front measurement.

Delivery Date: We will notify you in advance. If the date is inconvenient please let us know as soon as you can and we will re-schedule delivery to your area.

Access: Most panels will not pass through the house or via side gate with fixed head rail. For safety reasons please do not ask our erectors to lift buildings over fences or work on a base which is over 1.0m above ground level. Please discuss any delivery problems with the supplier before delivery.

Kitset Delivery: The kitset is delivered flat packed on its own pallet. Although it is desirable to unload as a complete pallet this is not always possible. When lifting equipment is not available cut the straps on the pallet and unload making sure all panels are stood up vertical against a solid wall out of the weather. Care must be taken unloading the glass.

Ground Bearers 4×3 (Standard Foundation): The foundation is the customer’s responsibility. Ground bearers are best made of 4 x 3 tanalised H4 pressure treated pine positioned at right angles to the floor joists. Care must be taken not to let these protrude past the edge of the building. It is essential to provide a solid level base. Attempting to assemble a garden building on an unleveled or soft surface will incur difficulties in squaring the building up causing joinery to jam or glass to crack.

Concrete Floor: If pouring a concrete floor, ensure that the base is laid accurately. This is because the bottom shiplap board is designed to overlap the edge of the base to provide weathering protection.

A ground anchoring service is available for buildings purchased without floors that is to be erected onto concrete foundations providing that there is 240 volt, 13 amp, power on site – see Fig.1 below

Paving Base (Suits a building ordered with floor): Lay pavers continuous, i.e. without gaps, over an area equal to the size of building. Leveling is easier if slabs are bedded on sand. Chipped/damaged second grade slabs can be used and are usually available from the local garden centres. To achieve required size, cut pavers and turn cut edge to face inwards. Specify bearers if base is oversize.

How we deal with inadequate foundations: If the foundation is not leveled or wrongly sized, we always erect if practical using temporary timber packing. It is the customer’s responsibility to make good. This may involve permanent packing under the floor or screeding inside a building ordered without floor.

If we are asked to erect very close to another building or other obstruction, we may not be able to fix bargeboards or nail the felt at eaves. (We recommend allowing 300mm (12″) clearance around the building. This provides the necessary access for the erector).