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Sealing off old underground sewage pipe to stop rats?

Postby Suzep » Thu Apr 16, 2009 5:07 pm

Hi, Please can someone help?

We've lived in our house for the last 18 months, and ever since moving in have had problems with rats getting under our kitchen floorboards and dying (even though we weren't poisoning them). After visits from pest control, a drainage survey and inspection all around our house we found a hole in the garden that seemed to lead under the concrete patio. Pest control advised that the houses in this area all had old outdoor toilets, that hadn't been fully blocked off, so we were advised to dig up the concrete to find any old pipes and seal them off. Thames Water advised us that if it was a pipe to an old toilet, then that would be our responsibility - so we should dig down and seal it off - otherwise they charge us £250 to come out and inspect.

This weekend we dug up the concrete outside of our kitchen, and found a pipe leading down in the direction of the main Thames Water sewer. There were a series of tunnels leading off from this area, one of which seems to go right underneath the foundations of the Party Wall with next doors house (we live in a mid-terraced house).

To see if the pipe was still being used by rats, we filled up the opening with soil and sure enough next day there was another hole dug through the soil. We filled the pipe again and the holes going into the walls - but these have not been re-opened. Today (3 days later) I found another dead rat under the kitchen floor - so am wondering if we trapped it inside the house.

We've tried looking under the floors of our kitchen by removing floorboards - and at the moment can't see a clear route through the walls - so it is still a mystery how the rats are getting inside - although now I'm thinking they have tunnelled under next doors foundations, and are then coming through a gap between the bricks under the floorboards into our house. (They never seem to come above ground)

I'd appreciate any advice on the following:

1. What do we buy to seal off the old pipe, and where do we get it from? Everything on the internet seems to be made of rubber, and I would have thought that rats could gnaw through this.

2. How do we seal up any tunnels or holes that the rats have made into the walls / under the foundations? Can we do this ourselves, or do we have to get a builder/specialist in?

3. How do we find out how the rats are getting in? Are there any cameras that you can use to inspect along the walls, or under foundations? (To look any further under our floor, we'll have to remove the fitted kitchen and I really want to avoid this if possible)

4. These houses all used to be council property, and some still are - is there any responsibility of the council to get the pipes properly sealed off and/or repair the foundations?

5. What risk is there to my house if the rats are tunnelling under the Party Wall? It looks as though we have very shallow foundations - maybe 2 bricks deep below ground level. The houses were built c 1900, so I think this is normal, but am not sure what we should/shouldn't be doing with regards digging around outside the house.

Thanks for any help people can give - this is driving me crazy, been hunting them down for around 6 months now, and still dead rats keep turning up!!
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Simply Build It

Postby stoneyboy » Sat Apr 18, 2009 12:49 pm

Seal the pipe and holes under the foundations with concrete - you can buy bags at your local DIY store. Use heavy duty rubber gloves and stuff the holes full of a stiff concrete mix.
You can hire an endoscope from your local hire shop - get one with a light source.
Your chances of getting any help sealing drains, from your council, is less than 1 in 100 but they may help poisoning the rats (there may be a fee payable). If you are finding dead rats the chances are that they are already being dealt with.
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Postby rosebery » Sun Apr 19, 2009 6:48 pm

"There were a series of tunnels leading off from this area, one of which seems to go right underneath the foundations of the Party Wall with next doors house (we live in a mid-terraced house)."

You need to be very careful that you are not sealing off the route to a currently used toilet in your own house or in another house before filling it with concrete.

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