Question: How Thick Is A Waffle Slab?

Can I pour a 2 inch concrete slab?

If done properly, new concrete can often be poured right over an existing slab.

For this to be feasible, the contractor needs to pour at least 2 inches thick, use smaller aggregate, and incorporate reinforcement such as welded wire mesh or fiber mixed into the concrete..

Do you need gravel under concrete?

Whether you pour concrete for a walkway or patio, a strong gravel base is required to prevent the concrete from cracking and shifting. Gravel is especially important in clay soil because it doesn’t drain well, which results in water pooling under the concrete slab and slowly eroding the soil as it finally drains.

How much does it cost to pour a 12×12 concrete slab?

The average cost to pour a 12×12 concrete slab that is 4” thick is between $888 and $1,584, with professional labor and materials included.

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.

How do you calculate slab depth?

The depth of slab depends on bending moment and deflection criterion….Or, the following thumb rules can be used:One way slab d=(L/22) to (L/28).Two way simply supported slab d=(L/20) to (L/30)Two way restrained slab d=(L/30) to (L/32)

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.

Can I pour concrete 1 inch thick?

There aren’t many reasons to have only a 1-inch thick concrete surface. It is too thin to use as a flooring just by itself; however if you need to resurface damaged concrete, a 1-inch layer is a good amount. The old surface is prepared so that the new concrete will adhere, then the new cement is added.

How thick is a slab on grade?

An article once reported that the thickness of one specified 6 inch slab varied from 2 ¾ inches to 8 inches, but the “normal” range should have been between 4 ½ inches to 7 ½ inches of thickness with an “average” concrete thickness of 5 ¼ to 5 ½ inches.

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 minimum depth of slab?

Slab thickness requires a minimum clear distance of one-twelfth the distance between the ribs and not less than 2 inches.

How much concrete do I need calculator?

For concrete, the formula for volume is as follows: length x width x thickness. To determine how many bags of concrete you will need, divide the total cubic yards needed by the yield. Use the following yields per each bag size: 40 pound bag yields .011 cubic yards.

How many 450mm slabs are in a square Metre?

Size: 200 x 100 x 50mm. Blocks per pack: 396. Blocks per m2: 50.

How far can a concrete slab span?

Reinforced concrete allows a wide range of structural options and provides cost-effective solutions for a multitude of situations—from residential buildings with moderate live loads and spans of about 25 ft, to commercial buildings with heavier live loads and spans ranging from 40 ft to 50 ft and beyond.

What is the lifespan of concrete?

Early 20th-century engineers thought reinforced concrete structures would last a very long time – perhaps 1,000 years. In reality, their life span is more like 50-100 years, and sometimes less.

How do you calculate concrete for a waffle slab?

Concrete CalculationsMultiply the total lineal meter of the edge beam by 150×150.Multiply total lineal meter of edge beam by the total height of slab by 50mm. Divide total m^2 of slab by 8.35 on 260 mm high slab. … Add totals of the earlier steps together and then add a further 3% to allow for wastage.

What is H class slab?

Class H – Highly reactive soil, a high amount of movement due to moisture. Class E – Extremely reactive soil, extreme movement due to moisture. Class P – ‘Problem’ soil, which experiences land slip, mine subsidence and so forth.

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.

What is a waffle pod concrete 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.

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.

What is the standard thickness of slab?

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 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.

Should you put plastic under concrete?

Recently, though, research has shown that the old traditional layer of 6-mil Visqueen (polyethylene plastic) under the slab is seldom effective for two main reasons: Although it may seem water-tight, this grade of material allows a lot of water vapor to pass through.

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.

Why have a waffle slab?

Built ‘on-ground’ rather than ‘in-ground’, the Waffle Pod Slab eliminates the need for labour intensive trenching – which is required in conventional concrete slab construction methods. Construction takes place on cleared level surfaces, allowing work to continue uninterrupted in wet weather.

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.

Is waffle slab good?

A Place for Waffle Slabs Waffle slabs work well on almost flat sites, natural soils or controlled fill, that have good surface strength and where the natural ground surface falls away from the outsides of the building in all directions (ie when the building pad has been built up with solid, water-shedding dirt).

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.

Can you pour concrete directly on dirt?

Long story short, yes you can pour concrete over dirt.

How much weight will 2 inches of concrete hold?

The weight of concrete is approximately 150 pounds per cubic foot, or 4,050 pounds per cubic yard. The formula for calculating the weight of concrete is: Length (in feet) x Width (in feet) x Thickness (in inches) /12 x 150 = weight (in pounds).

How much concrete do I need for a 5×10 slab?

Concrete Extras With a brief look, a 5×10 area at 6 inches deep, you would need approximately 1.31 tons or 0.93 cubic yards of gravel. Concrete reinforcing is also recommended in high traffic areas and medium to large areas.