Quick Answer: Are Waffle Slabs Bad?

What is a waffle pod slab?

This is where the concrete is sitting on (and around) a series of boxes (or Pods) set out in a grid pattern.

Think of a waffle pod as a raft lying flat above your soil.


• Waffle pod slabs are even stronger than conventional slabs, as the slab is poured as one piece..

Why do they put foam under concrete?

Concrete contractors learned that a layer of poly helps to keep a slab dry, because it stops upward vapor diffusion from the soil. … The foam layer isolates the room-temperature slab from the cold soil under the slab.

Where is waffle slab used?

Waffle slab can be used as both ceiling and floor slab. They are used in the areas where less number of columns are provided, i.e. it is basically used in th areas which has huge spans. Waffle slab is not used in typical construction projects.

How long can an I beam span?

In general terms, joists spaced 16 inches on center can span 1.5 times in feet their depth in inches. A 2×8 up to 12 feet; 2×10 to 15 feet and 2×12 to 18 feet.

How long does a waffle slab take to dry?

approximately 7 daysDuring the slab construction process, the slab will take approximately 7 days to cure, so be patient – you are literally watching concrete dry during this week! Once the slab has had enough time to cure, the plumbing and drains will be connected onsite.

Is it cheaper to build on a slab or piers?

While a pier and beam foundation will rest on the stone located deep below your home, a concrete slab will rest directly on the ground. For that reason, concrete slabs are ideal for homes that are being built on flat lots. Concrete slabs can be constructed very easily and are cheaper than pier and beam foundations.

Are waffle slabs any good?

They work perfectly well on non-reactive sites, slightly reactive clay sites and some moderately reactive clay sites. Waffle slabs are not recommended for use on highly reactive clay sites (Class H1 and H2) because the requirements for good drainage will be nearly impossible to achieve.

How far can a waffle slab span?

Waffle slabs are preferred for spans greater than 40 feet (12 m), as they are much stronger than flat slabs, flat slabs with drop panels, two-way slabs, one-way slabs, and one-way joist slabs.

How thick should a slab be for a house?

4 inchesStandard concrete floor slab thickness in residential construction is 4 inches. Five to six inches is recommended if the concrete will receive occasional heavy loads, such as motor homes or garbage trucks. To prepare the base, cut the ground level to the proper depth to allow for the slab thickness.

How much does a waffle slab cost?

On average, concrete slabs can cost anywhere from $75 to $110 per square metre. That’s still quite a spread, but it gives you a starting point for comparing quotes.

Are cracks in concrete slab normal?

ANSWER: Every concrete slab has cracks. Even when you don’t see them, slabs are laced with networks of micro-cracks resulting from common shrinkage. When new concrete hardens, shrinkage always occurs. And because concrete is not an elastic material, cracks are inevitable and rarely a cause for concern.

What is the difference between ribbed slab and waffle slab?

Ribbed slabs are made up of wide band beams running between columns with narrow ribs spanning the orthogonal direction. … Waffle slabs have a thin topping slab and narrow ribs spanning in both directions between column heads or band beams. The column heads or band beams are the same depth as the ribs.

Why are waffle slabs used?

Waffle slabs are used for larger span slabs or floors and used when there is limited requirement for number of columns. The load carrying capacity of waffle slab is greater than the other types of slabs. They provide good structural stability along with aesthetic appearance.

Which slab is better waffle pod slab or raft slab?

Slab Heave – Waffle Slab vs Raft Slab Why? Waffle slabs are built on top of the ground and need great drainage and really hard ground for the life of the building. Raft slab footings are dug into the ground, have more perimeter stiffness and more tolerance to poor ground conditions than waffle slabs.

How does a waffle pod slab work?

The construction process involves a building system of concrete slabs that are shored up by columns. The monolithic poured concrete will form a flat top surface while the rectangular grids form deep concrete beams on the underside, with the beams resembling waffle pockets spread out at right angles.