Concrete Waffle Slabs
Resembling the food after which they are named, concrete waffle slabs are reinforced concrete floors and roofs that use a square grid of deep sides. This form of construction is used in airports, parking garages, commercial and industrial buildings, bridges, residences and other structures requiring extra stability.
There are 3 basic designs for concrete slabs that improve the strength-to-weight ratio. Each combines a flat top surface with a modulated underside in a corrugated, ribbed or waffle design.
The innovative concrete waffle slab design adds strength in perpendicular directions. According to Tradeline, waffle slab construction is defined as "a building system using concrete 'waffle slab' floors supported by columns. The waffle slab is a monolithic-poured concrete slab with a flat top surface and an under-surface made of a rectangular grid of deep concrete beams running at right angles. The floor area between the grid beams is a thin flooring section. From the underside, the slab resembles a waffle. The floor is supported by columns spaced typically 30 feet on center."
Concrete waffle slabs may be purchased and shipped to the construction site as prefabricated (the most expensive type) or precast sections, or poured onsite. If prefab concrete is not in the budget, consider purchasing casts for the concrete waffle slabs.
PolySteel sells concrete waffle forms for walls. According to the company, insulating concrete forms earned a 4-hour fire rating and have a 27-year track record. The forms are available in 6", 8" and 10" sizes, plus 45 and 90 degree forms.
Concrete waffle slabs are often used in clean rooms, laboratories, or other areas that require isolation from low-frequency vibrations, and sites that require low-floor deflection.
Updated February 20, 2018.