On Sat, 06 Sep 2008 05:40:19 +0100, John Rumm
wrote:


Depends on the wall... on a wall made from 4" block or brick with
plaster over, you would not be cutting that far into the blocks. Stud
walls you could obviously run in the void. Also less of a problem on non
load bearing walls.

I'm afraid they are not stud walls, unfortunately. The problem is that
I don't know what is under the plaster. I think the door frame is
about 9 cm wide, so I guess it's a 9 cm block, and I know from having
lifted floor boards that the joists start over it, so it is bearing
the upstairs floor on it.

You can get chrome rad vales with built in drain points

I have seen these but they would drain to the bottom of the radiator
rather than the bottom of the pipe run, wouldn't they? I don't know
whether this would be a major problem? I think I might be better
tee-ing off the pipe.

Thanks,
Stephen.