thames water clay pipe - plastic connection - do or don't?

[biryani_boy]

I have a build over agreement from thames water and I need to remove an inspection chamber and connect two of the pipes in there to create a continuous flow. thames water has something in their guidance about using like for like materials, so clay in our case. I see most people using plastic pipes instead, even when only replacing/connecting portions of the entire run.

how strict are those guidelines? it's bloody difficult to find the right angle in clay, we'll need 2 or more pieces and even that is likely to be a few mm off.

thanks

 

[RonnyRaygun]

They won't check what you actually install if it's a domestic sewer.

 

[biryani_boy]

it's a "public" one, I'm afraid. stupid developers routed the neighbour's drainage into mine, from mine into their main one, instead of connecting theirs directly to the manhole in their garden.

we are also working with building control, if that makes a difference.

 

[thomp1983]

If there guidelines and you can't practically use clay then plastic will suffice, if there anything like severn trent they'll be more interested in your final cctv survey and report showing the sewer functions correctly

 

[RonnyRaygun]

it's a "public" one, I'm afraid. stupid developers routed the neighbour's drainage into mine, from mine into their main one, instead of connecting theirs directly to the manhole in their garden.

we are also working with building control, if that makes a difference.

It's "public" but it's still domestic, I assume. Therefore they won't check what you do (at least Thames don't).

Not telling you to bend or break the rules, but when I did mine they wanted me to build the new inspection chamber (basically just a rodding point) in brick to be like for like with the one on the public sewer that was being removed. I didn't see the point so I did it using a plastic chamber...

 

[biryani_boy]

I see. the only issue is that building control also insists on clay, which is a pain. existing pipes are nearly fossilised and at an awkward angle, making it difficult to connect them with existing connections. plastic would be much more reliable.

would it be worth asking Thames Water if they're willing to make an exception?

 

[SpecialK]

What's the issue with using clay? Saves having a lip...

 

[biryani_boy]

The existing pipes are brittle, I’m afraid they’ll crack when removing the concrete inspection chamber around them. Then there is the lack of flexibility in connections, it’s not at a pre-defined angle (15/30/45/90 degrees).

The builder seems confident he can sort it out without damage, but I panic easily, especially since something going wrong means telling the neighbours not to use any water/toilet.

 

[SpecialK]

Be fine, clay is strong. Angles can be cut and flexible joiners used.

 

[biryani_boy]

Thank you, I hope it all goes well.