Unknown rodent problem - advice sought

[MarkClacton]

Hi everyone,

Back at the end of last year, I noticed that the flexi pipe between the toilet pan and soil stack was leaking, and it turned out to be what I think was a rodent problem. There is little or no movement in the waste pipe, so this ruled out friction/rubbing so the only conclusion was rodents!

I have had the pest control people out, and all drains under the covers have been baited, but despite this, after 3-4 weeks, none of the bait has been touched. This leads me to think that the problem is not with rats, but possibly with squirels instead???

So, I have been to a number of local plumbing supplies shops, and no-one seems to be able to come up with a solution.

I have a standard flexi (long) 4" waste pipe connected to the back of the pan, which then connects off to the soil stack. I need a solution, ideally a non-return valve at the soil stack end to prevent any ingress at the point of the stack.

The only problem is that McAlpine do a non-return valve, but it's designed to be fitted to the pan, to prevent rodents coming up into the pan. This for me is no good, as I want to prevent whatever it is that is coming in via the soil stack from getting past that point. So that means a non-return valve at the soil stack.

Ideally I would have liked to have used proper plastic polypipe, but the angles involved just wont allow it.

Now - the McAlpine valve does actually look like it would fit onto the end of a standard 4" flexi pipe when the existing gasket/seal is removed, but guess what, they are indeed different sizes!!! The non-return valve is bigger than the end of the flexi-hose!!! The difference is probably only 2-3mm, but as we are talking water, I need to know that whatever I put in place is going to be water tight.

HELP - this toilet has been out of action for 2 months now, and I am getting serious aggro from the other half to get it sorted.

My layman thoughts -

1. Would one of these McAlpine non-return values fit inside the waste pipe - on the vertical drop (if you get what I mean - if I could get access)?

2. If the problem isn't rats coming up the soil stack, and it's something else coming from the top of the stack (I am sure the top is capped off with a soil vent) - is there any grates that I could insert above the toilet soil entry that would allow the ventilation to happen but prevent any ingress from above?

Any suggestions would be really appreciated.

Thanks, Mark.

 

[PhoenixServices]

You sure a stand bit of plastic soil pipe won't go in? Can you post some pics to a photobucket account and a link?

 

[Whyme]

Doubt its rats inside the soil and doubt its squirrels coming from above..Do you use rim bleach blocks or in cistern blue blocks cos they eat away at flexi wc connectors..?

 

[JCplumb]

Cheapest way would be to get your soil pipe or toilet in a position where you don't have to use a flexi pan connector.
There are soil pipe grates for the top of soil pipes, I used to call them crows nests, not sure if anyone else did 😉
There are also underground one way valves for soil pipes, so to fit one you'd be doing some digging.
There may be one way 110mm valves that you can fit vertically but I haven't come across any.

 

[MarkClacton]

Doubt its rats inside the soil and doubt its squirrels coming from above..Do you use rim bleach blocks or in cistern blue blocks cos they eat away at flexi wc connectors..?

The flexi was in-situ for 4 years of normal cleaning with usual toilet cleaners, not obsessively, with no problems at all. I replaced it, same problem in 2 weeks, and then replaced again and same problem in another 2 weeks.

In between the 2nd and 3rd one I used no toilet cleaning products!

Also, the punctures in the flexi appear in both the bottom of the pipe, where the water and waste would be in contact with most, but also above the water line too!!!

I am totally confused what could be causing it!!

I see fragments of the plastic flexi on the floor as if something has attacked it from the inside!!!

help!!

 

[MarkClacton]

I shall take some pictures of the flexi pipe, the damage etc and the positioning. I am not easily able to relocate the pan!!!

Thanks for the help so far!

 

[PlumbBobBob]

you could get something like this from mcalpine

 

[MarkClacton]

you could get something like this from mcalpine View attachment 20836

I went to my local shop and looked at this, but it is designed to fit the pan itself, not at the other end of the flexi. I offerred it up to the end of a flexi and they are different sizes (approx 2-3mm) so I don't think this will work.

🙁

 

[PlumbBobBob]

if you get a flexi on which you can remove the finned bit on the end, this will fit in it's place.