On 10/11/2011 12:55, Timothy Murphy wrote:

I live in a small part of a very large building (an old orphanage).
Strangely, there are no downpipes from the gutters
in the front of the 4-storey building.
All the water is transferred to downpipes at the back of the building.
Unfortunately the water goes over a valley in our part of the building.
The quantity of water after a heavy rainfall is immense;
it sounds as though a large river is running over one's head.
There is occasionally a slight leak through the ceiling at one point.

I'd like to put up a downpipe in the front of the building.
There is a place where this would not be obtrusive.
I would collect the water in a tank below.

Unfortunately two builders I have consulted have given different opinions.
One (a roofing expert) says that it is not possible
to attach a downpipe to the gutters, because these are cast iron.
The other expert says he can do it.

I wonder if anyone has a view on this?

Would it be possible to extend the downpipe(s) that empty into your
valley, so that the water bypasses it?

Colin Bignell