WHAT IS A WAFFLE POD SLAB?

A waffle slab is a type of reinforced concrete footing and slab system usually constructed at ground level. It consists of a perimeter footing (the edge beam) and a series of narrow internal beams (the strip footings) at one metre nominal centres running each way. They are basically reinforced concrete floors and roofs that use a square grid of deep sides. The whole footing and slab system is constructed on top of the ground.

The benefits of the Waffle Pod Slab are:

  • Reduced costs
  • Greater efficiency
  • Less concrete waste
  • No back-breaking digging of trenches
  • Simpler and more accurate construction
  • No lost time – you can still work when it’s wet

Waffle Pod Manufacturing

Waffle Pod Slab site in Sydney

Design

Concrete slabs are created according to three basic designs, of which the waffle slab comes out as the most efficient and innovative. Each of the slab designs focus on enhancing the structure’s strength to weight quotient, improving durability under different sets of conditions. All three designs also consist of a flat top surface with modulated undersides, which makes them different from one another and give them their unique names.

The modulated undersides can either be ribbed, corrugated or waffle.

  • Corrugated slabs are created by pouring concrete into a wavy metal form. This shape is inherent in preventing the slab from sagging under stress.
  • Ribbed slabs offer a very good form of construction where slab vibration is an issue, such as in laboratories and hospitals. They are made up of wide band beams running between columns with narrow ribs spanning the orthogonal direction (hence the name). Normally the ribs and the beams should be the same depth.

They are used to add foundation strength in one direction.

  • Waffle slabs tend to be deeper than the equivalent ribbed slab. Waffle slabs have a thin topping slab and narrow ribs that span in both directions between column heads or band beams. The column heads or band beams are designed to be the same depth as the ribs.

In Australia, waffle slabs are designed to comply with AS 2870.1-1998, AS 2870.2-1990. Concrete Structures Code AS 3600-1988 – The Australian Standard for Residential Slabs and Footings. The current version of this standard is AS2870-2011.

reinforcing mesh ready to be sent out to a construction site

Advantages Of Waffle Pod Slabs

They offer several advantages over their flat slab counterparts:

  • They are flexible.
  • They are relatively lighter, therefore lower foundation costs and longer spans are more economic.
  • They are much quicker to construct
  • They produce fairly slim floor depths
  • They offer more robustness
  • They provide excellent vibration control
  • They offer more thermal mass
  • Good for services integration
  • Durable finishes
A stack of Waflle Pods
waffle pod concrete slab being constructed