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Plumberpro, Plumber
Category: Plumbing
Satisfied Customers: 634
Experience:  Heating and plumbing answers. 20 years experience
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I have recently moved into a new flat. The building was built

Customer Question

I have recently moved into a new flat. The building was built in 1860's, and the previous occupier has recently installed a new en suite toilet. The issue I am facing is during heavy rain the shower is acting an an overflow to the rainwater pipe and risks flooding my flat.
To explain the building has a double pitched roof, with a flat section in the middle that has a drain in the centre to clear the rainwater water. The water goes through a lead pipe that falls vertically through an enclosed section in my hall, then the pipe curves underneath where the ensuite is, to run horizontally underneath my bedroom and leaves to join a outside pipe.
It appears the shower and sink plumbing have been connected directly into this pipe (toilet is on a separate saniflow system). After an initial incident, where water came up from the shower, I had an energy plumber who cleared the pipe. His thought this should solve the issue.
How're in recent heavy rain the issue has happened again, and so I now need to seek a solution. It is a fully tiled bathroom so access is not easy without causing issues etc. One though I had was that perhaps a one way valve system that could be installed to prevent the rainwater backing up into the shower. While this would take some work to do, at least it would not mean having to do a more major job of installing new pipe work. Would appreciate advice if this could work, or any other potential solutions.
Submitted: 2 years ago.
Category: Plumbing
Expert:  Plumberpro replied 2 years ago.
Hi yes,there are non return waste valves.The best is the hep2o by wavin. It can go inline on the waste pipe or on the shower as a trap..There is a link to it here
Customer: replied 2 years ago.
Thanks. My one concern with this solution, is if these style of one way traps are designed to deal with the potential water pressure possible from the drain pipe carrying rainwater.Your thoughts on this would be appreciated.
Expert:  Plumberpro replied 2 years ago.
Hi, yes they are designed to cope with this. Personally I would look to renew the pipe disconnecting from the rain water but I understand there are difficulties with this.