The waste pipes from my shower and bath to the soil stack, 40mm plastic ones, have runs of approx 2-3 metres. The Shower tray is set on a raised platform of approx 15-20cm. From the shower/bath to the soil stack the pipes rest on the floorboards completely horizontally, with a drop just before they join it. The pipes are hidden underneath/behind floor standing cabinets. All was installed around 3 years ago. I put a (literally) back-of-an-envelope diagram here:
What I did notice though is the unpleasant residue that seem to accumulate in the horizontal part of the pipes, and I am a little concerned that it will eventually cause problems.
Any suggestion as to how to give it the once-over? Pouring a half bucket of diluted Bleach down the bath and shower drains and leave it to rest for a couple of hours perhaps? What is rally important is that it would not be risky, as the access to the pipes (in case of damaging them) is all but impossible without having to rip the cabinets off the wall first.
Many thanks in advance.
J.