What are some key design features of Pod Floor Foundations?

Polystyrene Pods

The polystyrene pods act as void formers. They create a grid of hollow spaces within the concrete slab, which reduces the amount of concrete required, making the foundation lighter and more cost-effective. The pods provide thermal insulation, which can improve the energy efficiency of buildings by reducing heat transfer through the floor.

Grid of Beams

The concrete slab is reinforced with beams that run between the pods, both around the edges and internally. These beams are typically deeper than the slab thickness and are reinforced with steel. They provide structural integrity and distribute loads evenly across the foundation. The grid structure formed by the beams supports the building's weight and helps prevent differential settlement and cracking.

Reinforcement

Steel reinforcing bars (rebar) are used within the beams and sometimes throughout the slab area. This reinforcement helps the foundation resist tensile forces and improves its overall structural capacity. In some designs, a mesh reinforcement is also laid across the top of the pods before the concrete is poured to enhance the strength and connectivity of the concrete.

Construction Technique

The ground is prepared typically with a layer of compacted sand or gravel to ensure a stable and level base. The polystyrene pods are laid out according to the foundation plan, followed by the placement of steel reinforcement, and finally, the concrete is poured into the formwork to create the slab and beams in a single operation.

Moisture and Ground Movement Adaptation

Measures such as a vapour barrier might be installed beneath the slab to prevent moisture from rising through the concrete. The design of pod floor foundations can adapt to various soil types, including reactive soils that expand and contract due to moisture changes.