I am doing a job in a building that has just been built. The concrete floor has been poured 10mm low in places and 21mm high in others - does anyone know the tolerances in British standards for poured concrete. I may make a clai if they are over the limits.
Poured Concrete Tolerances
Dec 15, 2006
12 Replies
I'd say that's entirely up to you to negotiate with them beforehand.
No, negotiate what's appropriate for the job, and what you are willing to pay for.
For some jobs, +-150mm may be quite appropriate. For others, +-1mm would be appropriate.
Any standard can only logically reflect this.
If the tolerance wasn't specified, you haven't got a lot to go on - though that does sound rough -just pokering it would bring it up more level than that.
Who laid the floor? - whoever it was, get them back and tell them to get it fixed...there are no such thing as tolerances in pouring concrete, the idea is to stop when it's full to the desired level, although if this 30mm deviance is over a large area, IE, the floor area of a house, then this is generally accepted.
BTW, 10mm and 21mm lower and higher than what exactly?
I don't think there are any.
One wold normally screed over poured concrete anyway. For levelling. Its a bitch to get it flat at the best of times.
Only if you have the house built by a bunch of incompetent monkeys
The datum.
No, it's accepted everywhere, get a long straight length of timber and a spirit level and you'll soon find discrepancies in your own (and everyone elses) house
Is that above or below the DPC?
The slab is a lowered portion of a larger building I am building a music studio with a floated floor in. I meant the discrepancies are higher and lower than the figure of 200mmm below the finished floor level of the rest of the building. I think I am going to have it screeded now. I wondered about the BS standards as when I complained to the architect she said she thought it would be within the tolerances of British standards. I asked for this to be 200mm below FFL and they knew my tolerances were tight. I'm interested as to whether I can get them to pay for the screed as it is now at my expense.
Phil L wrote:
No, if you get it laid correctly +/- 5mm over 10m is easy - finding the long straight length of timber is in my experience more of a problem.
The datum, there might not even be a DPC.
+or- 5mm over 10m is acceptable by you then? - as I said earlier, 10 - 30mm is generally acceptable, especially if it's over a large area, you say 10m, the Op doesn't state his area size, nor what he considers acceptable.
There may not have been a datum, we are guessing.
If you are using the concrete slab as a finish, then you should have specified this and the builders used proper leveling and finishing equipment.
Many industrial units require level floors, so it is possible. But this may not be feasible in a domestic setting.
In either case, the standard expected should have been specifically stated in the contract documents, otherwise how do the builders know what you want?
dg
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