How do you seal off redundant pipes

[Rslee]

Our extension will be built over a manhole for foul waste and a new rodding eye installed outside of the extension. Three pipes for foul waste from the existing house converge at this manhole which then turns into a single pipe running to the communal sewer under the new extension.

Two of the three pipes from the existing house won't be needed after the extension is built so we want to make sure they are sealed off. We have had really smelly drains before. Builder says that the pipes will just get capped near the existing house and that is it. Building inspector said the concrete plugs are needed at manhole then half circles are used to close pipes at the manhole before concreting over the manhole. Builder said he spoke with building inspector today and bs said capping of pipes was fine. I will obviously check with bs what was said but wondered if someone could advise me on standard procedure when building over a manhole which does not need access. Capping of pipes seems simple but last thing we want is cap bursting off and sewage leaking somewhere under the house!

Many thanks

 

[Best]

Ideally if the 3 pipe going into 1 pipe manhole is being changed into 1 pipe going to 1 pipe, then the pipe should be connected together with no manhole used at all. May not be easy to do that if pipes are old types or hard to get at

 

[Unregistered]

Many thanks - that is a really good idea - we have a rodding eye which could be one of the forks and the drain from the house the other which converge at the position of the manhole. Will try and speak to builder tomorrow but he seems to be happy just capping pipes near house and doing nothing at the man hole.

 

[Best]

Lots of builders, - and I am not saying your builder, - just want to do it the easy way often.
Manholes tend to be a place where sewers can block easy. Not so bad if they are outside the building, but I wouldn't want one buried inside a property.
You don't want a nightmare in a few months or years below your home

 

[joni os]

Full agreement with previous post. Manholes are a source of blockage and unless access is maintained ,(double seal screw down cover), then it is best to remove manhole and pipe through with Y connection and external rodding access.

 

[spanner]

Lot of work.

 

[Rslee]

Thanks all - so sounds like one pipe from the house and joining to Pipe which leads to public sewer would be best. This would join at point of the existing manhole with a slight chance of direction. Therefore at change of direction (where existing manhole is) there will be a branch for a rodding eye - in effect some kind of y connection. The existing manhole will need to be removed and redundant pipes removed too. Hopefully this is not too much work for the builder!
I'm not confident that builder knows too much about drains. Would this normally be left to builder or plumber?

I may draw this out and scan to people to check I have this correct, if ok

 

[Ermintrude]

You need a build over agreement from local water board. For a start.

Builder sounds like a typical builder.......

 

[Rslee]

Hi there
thanks for your reply- we had a heated discussion with the builder yesterday and he has agreed to use a y connection so that we have sealed pipe coming from the house and to remove the manhole. The other 'fork' of the man hole will lead to a rodding eye.
I have just spoken to a neighbour who removed a manhole and he mentioned something about having to lintel over the new pipes. Is this something we would need to do? I thought that you only lintel over the sewer where the wall of the new extension is being built.
Thanks again!!!!

 

[Best]

I have just spoken to a neighbour who removed a manhole and he mentioned something about having to lintel over the new pipes. Is this something we would need to do? I thought that you only lintel over the sewer where the wall of the new extension is being built.
Thanks again!!!!

All new walls built over a sewer pipe must have a lintel above them with modern regs. Not sure about existing walls. You could ask your local building control

 

[spanner]

If it was redundant I thought you can fill it with grouting concrete cement.. sorry guys I'm just reading through the thread just now.