main sewage pipe.help needed!!!

Hi all, hope someone has a idea! I am planning an extension at the rear of my house and have come across a bit of a problem. There is a manhole cover in the way of the footings and i have to move it, the problem is that this is the manhole over a 6inch communal sewer and the pipe the whole width of the garden is coverd with a foot of concrete.I am planning to build over the 6inch sewer pipe but would like to replace the whole length under the new extension with plastic to eliminate any joins and possible problems.Any ideas on how i can transfer the constant flow of poop whist i work on the pipe and is it possible to connect plastic to 6inch clay without causing and possible snag points inside the pipe?
cheers for any advice

If it serves more than one pre-1936 property, it's not yours to play with, it's your local water company's. In which case, you need to - try and - get their permission to build over it and for any alterations that you want to make to the pipework.

If it's not a public sewer and you're concerned about possible future problems, the pipe can be lined with a flexible liner, which is resin bonded to the inside of the pipe. Saves digging it all up, costs about £60/m plus VAT, local drain specialists can sort it out for you.

Pipe upstream of the manhole can be bunged with inflatable stops to allow work to be undertaken. Watch out if it slips though....

Yep, the building control guys will pick it up if its a public sewer and refer you to the local water company who will then squeeze you tightly for fees, permission and scam a free drain survey out of you.

Its either a bung in the pipe, or a bung and some sort of pumping arrangement

Thats a real crappie job you are proposing, and I would phone in sick on those days! lol

And watch out for the ones with dents in the ends....

we have done just the same thing and you are very wise to replace with plastic.

provided you own the pipe and not the water board then it is not a problem.

we bunged the high end with a purpose made screw type bung with a centre water release cap. start the job after 9:00 a.m.

we hoofed out the drains complete with concrete right across his property, using a micro digger

we then used fernco clay-plastic connectors at each end and coupled up the new plastic pipe and back-filled with pea gravel only half way up the pipe. this is so building control can have a look and pass it. you can completely surround the pipe with pea gravel once b.c. have finished their inspection.

don't worry about size difference, the bore of the pipes is pretty much the same.