DIY Doctor UK DIY Forums

We've just moved into a new house which has an internal soil stack. While investigating a leak from shower we unboxed base of the soil stack. Where it enters ground it is surrounded by packing of soil/putty type substance, this was originally damp from water dripping along pipe from shower leak. Having solved the leak we expected everything to dry up. A month or so later the area is drier but packing round base of soil stack is still slightly sticky and there is a small amount of dampness on surrounding floor.

Is this normal or do we have another problem? The base of soil stack is in a small shower room and is obviously now exposed, could it just be attracting condensation? Any insight gratefully recieved.

I had a problem with mine last year - internal soil stack. Where the cast iron joins the clay pipe has fractured and the drain has dropped causing the water to back up.

Had to cut out the cast iron and clay and renew using plastic pipe and fittings.

Lift the manhole and get someone to watch as you flush toilet tissue down the toilet, if the drain is clear the tissue will quickly appear in the main drain. If it doesn't there could be a blockage causing the drains to back up and leak.

If it is clear you could still have a slight leak, you can soundness test drains using hand bellows, bungs and a u gauge.


hope this helps