The Challenge

A foundation and floor solution was required for a residential extension close to protected trees.

The extension was to incorporate a utility room and garage.

Minimal excavation was allowed within the root protection areas of the trees.

Heave protection was required in order to protect against the volume change potential of the ground.

The Solution

A piled suspended concrete slab was designed with heave protection void former.
QuadraPile helical (screw) piles were installed in a grid across the area before the heave protection boards were installed.
Two layer of reinforcing mesh were then installed before the concrete was poured to form the slab.
The walls could then be built off the slab.

A step height change was incoporated in the slab to enable insulation in the habitable space and no insulation in the garage and also to keep the slab above ground level in the root protection area.