I intend installing an en-suite in a bedroom.

Waste from new toilet will go straight through & down the wall then 
underground to meet the waste pipe from the existing toilet.

Question is, do I need a new stack for new soil pipe  or will existing stack 
serve both old & new toilets?

cheers

Andy

you will need to vent this new waste ,or you could cause your self some
problems,a new stack though may not be needed with modern vent systems

"Alex"  wrote in message 
news:des4l3$sof$1@nwrdmz01.dmz.ncs.ea.ibs-infra.bt.com...

> you will need to vent this new waste ,or you could cause your self some
> problems,a new stack though may not be needed with modern vent systems
>
>

Thanks for the reply.

So how would I go about it then?

Andy.