Question: Are Waffle Slabs Any Good?

How long does a waffle slab take to dry?

about seven daysA: On average, it takes about seven days for a waffle pod slab to thoroughly dry.

While it does take some patience, the wait will be well worth it..

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.

How long can an I beam span?

The taller the beam, say 10 or 12 inches rather than 8 inches, the greater the distance you can span between support posts. I had spans as great as 14 feet in my own basement using the 10×31 steel beams. Heavier beams can sometimes span greater distances between posts.

How does waffle slab work?

Waffle slabs are a reinforced concrete footing and slab system constructed on the ground. … Waffle slabs achieve their strength by varying the height of the slab above ground. The higher the slab above ground – the deeper the beams. The deeper the beams – the more stiffness the system has.

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.

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 is foam used in concrete slabs?

They reduce the effects of soil movement, decrease the amount of concrete required, and have thermal insular properties making them a cost effective component for any home, building or complex. In traditional slabs, the bottom of the slab uses footings based on concrete beams which require extensive digging.

What kind of foam goes under slab?

expanded polystyreneTwo of the rigid foam insulations most commonly used below grade and under slabs are expanded polystyrene (EPS) and extruded polystyrene (XPS). Although both are closed cell insulations, they perform very differently over the long term.

Can you use spray foam under concrete slab?

Insulating under foundation and basement slabs using SPF (spray polyurethane foam) offers certain advantages over the more common method of using rigid foam board. … Two-pound foam. Only closed-cell SPF can be used in a subslab installation; the open-cell foam does not have adequate compressive strength.

Can you insulate a concrete slab?

Creating an insulation layer and a vapor barrier between the concrete slab and the ground beneath it is the best practice in insulating basement floors. The insulation barrier will help keep warm air in, and the vapor barrier will keep unwanted moisture out.

How much does a waffle pod 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.

Is it normal for a house slab to crack?

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 an M class slab?

Class M means that the soil found on your clay or silt site is moderately reactive. The movement expected from this type of soil is 20-40mm. Class M sites require a stiffened slab with cross beams in the slab. The stiffening prevents the slab from twisting and bending as the clay soil moves.

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.

What is a waffle pod slab?

SLABS. WHAT ARE WAFFLE PODS? 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.

What is the maximum span of a slab?

The answer to question is simple, the limit to span is about 6–15m depending upon how much you spend because as the length increases depth of slab increases since bending moment is increasing and the structure will become more and more uneconomical.

How much does a raft slab cost?

At about $50/m2, the average cost of concrete slabs in Western Australia is the most affordable across the country. This is followed by the average price in Queensland and Victoria which is $60/m2. Concreters in New South Wales charge the highest for concrete slabs. Their rate is around $85/m2 on average.

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.