We have a flat that has issues with a toilet (main bathroom) backfilling into the en suite loo when flushed. Without too much detail, some coloration issues have progressed into 'solids' issues! We're not talking vast amounts, but enough to be obvious.
Now, not being very handy I've got a 'man' in who smashed away some tiles on the boxed in section behind the en suite loo. We had suspected that the fall of the soil pipe was not sufficient (the soil runs from the en suite, past the main loo and then into the communal pipe near the entrance to the flat). We also expected the soil pipe to be a straight line.
However, when the pipework was exposed the situation was slightly more complex. The soil from the back of the en suite goes immediately to a 'T'. From the right is a small diameter drain from the immersion tank. The soil takes a 90 degree bend to the left for about 18 inches before a 90 degree bend to the right, which then straight lines past the main loo to the communal soil. The main problem is the the 90 degree bend to the left (18 inches) is not only suffering from a lack of fall, it actually goes up slightly!!
We have tried raising the soil behind the en suite but leaks begin to appear if this gets stressed too much. Without knocking massive holes in en suite and main bathroom walls (tiled) and re-laying all the soil pipes, the only solution appears to be lifting both the immersion tank and en suite loo onto plinths. Although feasible, the height gain will have to be significant just to climb onto the loo!!
Are there any other methods or solutions (assuming I have explained myself)? The guy that came in started going on about saniflow macerators but tailed off and admitted he was out of his depth...
Any help appreciated. Macclesfield based if any one in the trade in that area?
Thanks


