How long does a Slab take to 'settle?'

Our slab sat for three weeks before they started the frame. It seemed like a long time then, but the rest of the house is going up so fast, that we have overtaken other houses that were being started at the same time that used waffle pods and had the frames put up the next day.

Our slab used Waffle Pods, was exactly three weeks from the day the slab went down to when the frame work was up and finished (frame work took two days). Think that was more about the scheduling of the builder, not so much the time it took to set. We had steady showers on our slab so hopefully it should have cured nice and slowly.

Here is some information that I found on a website

Curing of all cement-based building materials is critical to achieving the design strength and other desired properties, especially with structural concrete slabs. Concrete takes 28 days to reach the design strength, although a sufficient minimum design strength may be achieved in less time if the concrete is specified accordingly. It is essential that the curing regime specified by the design engineer is followed exactly.

http://www.greenhouse.gov.au/yourhome/t ... /fs34f.htm

Yet on another website it says

Q:
What is curing and how do I cure my new concrete slab?

A:
Concrete hardens as a result of hydration, that is the chemical reaction between cement and water. Hydration occurs only if water is available and if the concrete's temperature stays within a suitable range. After placing concrete, the concrete surface needs to be kept moist for a period of time to permit the hydration process. this period is referred to as the curing period and is usually 5-7 days after placing conventional concrete. New concrete can be wet with soaking hessian, sprinklers or covered with wet hessian or plastic sheets or can be watered with commercially available curing compounds which seal in moisture.

http://www.concrete.net.au/faq.php#4

Could not find anything about when you could start building on it exactly

For us our Waffle Pod slab went down on the 2nd of july.
7th july they began laying out bottom plates.
9th July they began framing.
Hardwood tassie oak frame.
currentlythey are finishing off brickwork and roofing, windows and glass sliders are in.
cheers

cry&cbear,

There's some amazing information on the web, if you just know where to look (and have plenty of time).

Thanks to law18, one of the websites that was listed led me to a great concrete website. I call it everythign you ever wanted to know about concrete, but didn't have a lifetime to read it. It's the Cement, Aggregates and Concrete Australia website:

www.concrete.net.au

One of the datasheets on the website is entitled Curing. From the datasheet we have, compared to curing for 180 days, "concrete
allowed to dry out immediately achieves only 40% of the strength of the same concrete water cured for the full period of 180 days. Even three days
water curing increases this figure to 60%, whilst 28 days water curing increases it to 95%. Keeping concrete moist is therefore, a most effective way of increasing its ultimate strength."

So I would go for curing for 28 days. This should result in a great concrete slab and minimal problems in the future. Note, this is curing for 28 days, not just waiting for 28 days. From what I can gather, curing can be as simple as leaving it covered with plastic.

Hope this helps.

Cheers,
Casa