Matt wrote:
On Sat, 16 Dec 2006 19:53:25 GMT, "Phil L"
wrote:

Matt wrote:

Only if you have the house built by a bunch of incompetent monkeys

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

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.

+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.

BTW, 10mm and 21mm lower and higher than what exactly?

The datum.

Is that above or below the DPC?

The datum, there might not even be a DPC.

There may not have been a datum, we are guessing.