Bungs for sewer back-flow?

[N_Cook]

Since the recent Coverack inundation and finding an archive newspaper ref to a similar event ,locally , 60 years ago. Where we are the problem is roof-run off rain getting into the sewer system , from thousands of older houses, then the sewer system directly under us going to a large sewage works, that cannot handle such inundations, and all backs up rainwater and sewage. I assume 4 inch/100mm sewer pipe screw-enlarge test bungs would be too large for the first bend of bog-pan traps. Kids plastic beach ball perhaps , firmly pushed down there and cut to remove later perhaps. Sink and bath plugs weighted down with anything heavy , but how to temporarily block off sink and bath overflow holes? any other ideas?

[Tim+]

Almost the first hit on "sewer pipe valve".

Tim

[Nightjar]

All grey water in my house drains into the foul water sewer via outdoor gulleys. Hence, if the sewers do back up, there is no direct link between them and sinks, handbasins or bath. The water outside would have to be above the height of the kitchen sink to come in via its waste pipe (the WC is upstairs) and I doubt the rest of the house is waterproof to that depth.

[damduck-egg]

or you could possibly find a small inflatable ball and a bike pump will do a similar job for a lot less.

You really need something that can be swollen to make a seal and get some friction to hold against the pressure ,you will be lucky to find a kids ball that will be just right.

Depends if they have grills and sometimes chains fixed in them. You could possibly make something out of a wooden disk of with a couple of small diameter hook bolts through it, poke the hook bolts though grill of overflow through,turn them a bit and then clamp wooden disk with nuts which I would make wing nuts for ease of use. You would have to make the wooden disk thick enough that the nut has some thread to bite on or make your own J bolts by bending some small diameter threaded rod. Around the edge of the wooden disk you would need a seal of softer material or a ring of sealer. If your overflows have holes you would have to make the J of the J bolt quite small.

Isn't the that the sewage works that Southern TV or TVS showed a clip of agitated effluent after the announcer said " and now over to our guest Omar Sharif ", realising the error the controllers quickly switched, unfortunately to a picture of a Donkey.

It was a long time ago so it may have been another actor.

G.Harman

[N_Cook]

Yes the people most liable to marine flooding , 1 in 5 year or so , have one-way valves now fitted in their systems along with loads of other stuff. Put the people in the slightly higher areas, who may get a 1 in

50 year intense rainfall event and should have an emergency procedure available, in the interim, before they know for certain about this other flooding scenario, after the next such event. Incidently the set of new one-way valves presumably increases the chance for house interior sewage flooding, as no longer that pressure releif lower down

[N_Cook]

I was thinking of bar of soap , squashed in the vents ,then a pad/plate and then pre-prepared length of dowel to the other end of bath / sink.

My favourite not-outake, was a young cub reporter on BBC south , presenting a piece about an open-top bus tour somewhere , handing back to Sally Taylor with the line "now back to someone who also likes it on top"

[The Natural Philosopher]

Football bladder surely?

[Brian Gaff]

You would think one of those big flap like sprung wotsits they used to use might have been very handy for back flow protection. Just don't see such things these days. Brian

[N_Cook]

Good idea. Plus a bag of spuds or woven shopping bag of garden soil, placed on top , in case it slips. I'm aware quite a lot of air pressure can build up , prior to the sewage proper , getting anywhere near. Because of marine flooding events , the usual air-balancing vents to the manholes are absent, air-tight covers instead.

[Jonathan]

Our local council has fitted something with a flap inside our main rain water drains around here to stop the river coming back uphill when we are close to flooding. I would have thought something similar would do the job.

Jonathan

[N_Cook]

If they are like the flap-valves local to me, next to useless. Bits of wood, branches, even slabs of polystyrene like to hang around the lip after floating up the pipe and then back down,or from farther up the pipe, but not out, as they are no longer floating at that precise point, clever really