I doing two bathrooms, which are back to back, the toilets I was hoping to run into the same length of soil pipe before it goes out of the wall into the main stack
what minmum distance is recomended between toilets so as not to get back flush problems should both be flushed at the same time
The soil has approx 20mm drop from 1st tiolet to outside wall and is approx 1m long
cheers