As I am approching the completion of the extension I have been working
on for far too long, I have started to think a little more about using
some of the extra space which I now have in one of the bedrooms. It
had long been in the back of my mind that we might put an en-suite
shower/wc in. My original thought was that I would run the soil pipe
parellel to the first floor joists between ceiling and floor, out
through the wall and then across the back of the house to connect to
the existing stack.

Last night I had one of those moments when you suddenly realise that
it wont work the way you have been thinking about from the start. The
reason is that at the point where it should pass through the wall,
there is a great big lintel carrying the wall where the opening into
the new conservatory is. I seriously doubt that there is sufficent
space between the floor & ceiling to permit the soil pipe to pass over
the lintel and still achieve any kind of fall across the length of the
pipe. I can't really drop the pipe beneath the lintel as it would
then be visible from beneath and boxing it in would look quite ugly.
Running it above the floor wont really work either without adversly
affecting the proposed layout of the room. I am beginning to wonder
whether we will have to do without the ensuite W/C.

At the moment the only thing I think that might work is if I can get a
smaller bore soil pipe which will pass over the top of the lintel. My
builders merchant does a 3" soil pipe but I'm not sure whether this is
permitted for a W/C, whether you can get all the required fittings if
it were (e.g. pan connectors) or even if this is small enough. The
only other way I think would be to use a macerator toilet but I have
no experience of these and I don't even know what size waste pipe it
would need. Any opinions on these will be greatly appreciated, as
will any other ideas you may have.

Thanks.

Kevin.