Concrete floor flatness


Hi,
We've just had a concrete floor done by a professional builder and I'm proposing to lay a wood floor over it. However I'm not convinced the floor is level enough - I'm seeing variation of maybe 7-8mm over a 1m length of floor, and there's no way the underlay is going to be able to take up that much undulation.
Would you agree that this isn't flat enough to lay a wood floor onto as it stands?
I'm going to insist that the builder comes back and improves the flatness (levelling compound or rescreed the floor or whatever) before we make the final payment. Does anyone know if there's a standard for acceptable flatness of a domestic concrete floor specified in Buildings Regs or anywhere similar?
Cheers, Nick
snipped-for-privacy@SPAMTRAPDELETEiee.org
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8mm to 1 metre is almost guttering specification for water drainage are you sure the whole area is'nt deliberatly slanted to allow water to drain away?
If its up in one place and down in another, get him back to re-do -- Vass
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I remember being around when our new kitchen floor was laid, and the builder couldn't have been more careful with spirit level on a long straight edge etc. I was very surprised when I later installed my kitchen units to find that there was a 19mm in 60cm slope under the units.
At work we had builders relay a floor 3 times trying to get <6mm in 10m - they claimed they could do it, but we measured and rejected as it was necessary for correct assembly of a screened room. Eventually we employed the guys responsible for the fountains in Milton Keynes, and they got it right - no problem.
--
M Stewart
Milton Keynes, UK
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I should emphasise that what I'm talking about here is not a slope - it's undulation, i.e. there's at least one 'valley' in the floor that is about 70cm wide and about 7mm deep in the middle.
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I did my floor screeding 5M x 4M I was told to lay out the floor with 2x4 timbers leveled and just drag with stright/flat 2x4 worked fine for me, installed new kit no problems
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