Stiffened raft slabs

Slab footings consist of concrete beams and floors across the entire floor plan. Slabs are also referred to as slab floors, slab on ground or raft slabs. Slab is the general term used to refer to any of the available types of slabs.

The stiffened raft slab is the simplest and most common slab construction available. The stiffened raft configuration can be used on all classes of sites (except problem sites - Class P).

Stiffened raft slabs consist of:

  • 100 mm thick concrete slab
  • edge beams
  • internal beams (except Class A and Class S sites)
  • steel reinforcement.

The concrete is poured in one operation.

Diagram showing the structure of a stiffened raft slab. The edge beam has a rebate and there is an internal beam central to the slab. The slab thickening for load bearing walls more than one metre forms internal beams.

Diagram of an aerial view of a stiffened raft slab. It is divided into a grid of internal beams with concrete in between the beams and beams around the perimeter of the slab.