So, first morning of the long weekend.

Have you noticed that wet patch says she!

Fortunately near an existing access point in the landing floor. A 15mm
copper pipe with a slight weep although her vanity mirror got lost under
a Gorilla's armpit of pipework. Bathroom soil, shower waste, basin
waste, 6 lots of 22mm pairs... heating, boiler flow/ret. and hot/cold
offtake.
So, through the ceiling then. Nice rectangular cut for easy re-fitting.
Levered it down carefully and got an immediate shower of water, about as
fast as I used to be able to piddle!

Not mains, turned off. Not gravity cold, turned off. Not hot.... oh ****
it must be central heating. But the valve is off, the rad stats should
be closed... oh **** again it must be the bathrooms which are open for
boiler overrun!

Luckily we have buckets and the water was surprisingly clean.

The fault turned out to be a galvanised nail (plasterer) which had just
entered the pipe wall leaving a neat square hole. Nicely sealed for 23
years so why pick today?
--
Tim Lamb