Soil Pipe in my House ( new connection help )

2 Feb 2020
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United Kingdom
Hi All,

Wonder if you can help. I've taken on a home DIY project of adding a new bathroom in my house and planned on moving my down stack from upstairs. The big issue i have is the Cowboy of a builder who built my house never ran my soil pipe outside of my property it goes directly underneath my kitchen through my garage and into my neighbors house.

With this in mind there is no way i can install chamber outside of the property to allow for easy simple connections. ( floor plan image, "red line is exisiting" "blue line is new pipe" )

To complicate matters futher my soilpipe is 1.2m below the level of my garage floor making access for rodding nearly impossible.

Im attaching some pictures of my excavated pipe in the hope you might be able to assist me.

My hope was that i can connect into this existing pipe with a Y piece which runs at an uphill gradient to my new bathroom area with a rodding/acces point in the bathroom. Then with the exisiting run put a rodding point there to go down the straight run.

Still futher making this a tricky sitiuation the propery currently has NO Rodding points outside the toilet and the Main drain location 3 houses away!!

I do hope someone is able to assist or advise on this. Do i need to do some pleading with my BCO!

Thanks in advance,



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What has your BCO said? Are you not able to re-route in front of kitchen externally and connect back up in garage or install a manhole in garage?
I am doing an extension at the front of the kitchen which would make the svp that currently comes down in the kitchen be even further into the house. I need to run a new pipe for the kitchen utilities once the extension foundations have been placed.
This still doesnt help that much with the fact that my outgoing Soilpipe exits directly into my neighbors garage. I am unable to dig up my neighbors drive / property to install a new pipe.

I havent spoken to my BCO yet as i only found the pipe today.
Plenty of houses out there with drains running underneath, manholes would only be provided where needed. Had a few head scratchers in my time, trying to locate where the drain goes, only to find the manhole was 3 doors away...

If there is absolutely no other option available, installing a chamber internally will be the only solution. It will need to be fitted with an airtight, screwed down cover, (and hope you never need to open it!), at 1.2m you should be ok with a 450mm diameter plastic chamber.
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Thanks for the reply hugh, unfortunately I don’t think another option is available. A 450mm chamber could work I’d have to excavate more underneath the floor to get a larger chamber instead, I was hoping the smaller chamber would work but if I understand correctly you can’t put them more than 600 below ground. I’m planning on making a hatch in the floating floor that’s being used to raise the floor level up.

we only found our soil pipe due to gps tracking/ camera work. Tho we knew where it ended up we didn’t know how it got there.
You cant use the smaller chamber over 600mm as you wont get rods or a jetting hose down there to clear any blockage. 450mm chambers are only permitted to a certain depth for the same reason. Unfortunately you need to dig some more out I suspect.
Do you think I might be able to get away with a slow 90 with rodding access in the bend? As it won’t be the main flow side as it will be at the top?
I have BcO coming today at 1pm. I’ve just measured and a 450 chamber physically won’t fit between my beams even on its side..
so an update on the situation given by the BCO this is what they suggested.

In my existing kitchen i remove my current soil stack / vent and install a digo valve at 250mm from the floor.
In the garage they will accept a Y piece connection into a Slow 90 then straight up to the upstairs bathroom waste and vent.
Within the upright i need to put in an access point, and on this Stack i then T-piece in my new downstairs bathroom and put a dirgo vent on that as well.

As my drain is a unique one and not shared it can be rodded back from the main road chamber and then also from the 3 different directions.

All in all best possible outcome and alot easier than trying to install chambers that dont fit!

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