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Crumbly cement 18 hours later
We've had a sandstone patio laid, the job isn't complete yet but I'm worried about the concrete as it doesn't seem to be set enough.
Dry weather laid in 18 degrees so average weather.
It was finished 18 hours ago and there's still some slabs to lay. I poked a bit of the concrete poking out under the slabs and it was rough but soft enough to push my finger into it. I was able to poke bits of it which then easily crumble back to a coarse sand mixture between my fingers. Is this normal, as my previous experience is that I've been able to walk on solid concrete the next day and this is only a 2 inch layer under slabs and its so crumbly. Your advice would be greatly appreciated as builders are due in an hour.
It won't have completely set in 18 hours and I don't allow people walking on sandstone for at least 24 hours after it's laid. You would still be able to crumble it in your fingers after 24 hours but shouldn't be able to push your fingers into it.
See what its like after 48 hours, if you are still not happy talk to them about it.
Answered 27th Sep 2013