Locating Sewer Pipe

[aaront]

I want to move my WC. This obviously means I have to lay a connection from the new WC site to the sewer line - but how can I find out where it is?

I have rung the council planning dept - they dont know. I have rung both water authorities that deal with my flat - they dont know anything apart from where the main drain is in the centre of the road.

Is there any way of finding out where the sewer pipe is short of digging down the existing soil stack and following it round?

Help me DIYnot, you're my last hope!

 

[masona]

Can you not connect it to your existing soil pipe?

 

[aaront]

The site for the new WC is 2 rooms away. It would mean about 10 metres of pipe around the outside of the building.

 

[masona]

Providing you got a fall and not many bends,I can't see you will have any problem unless I missed something here,the only thing would be an eyesore to look at.

If you want to dig down the sewer line you would have to build a drain inspection manhole which involves a bit of work.If you're thinking putting in a Y-piece you would have dig a long trench and lift up approx 3 to 4 length pipe to slot in the Y-piece and can you unblocked it if you have any problem there?

 

[aaront]

The other thing is that the existing soil stack is cast iron and very old, God knows how difficult it would be to cut into it to join the new pipe.

What sort of fall do I need by the way?

 

[masona]

Can't remember long time since I done one,I think it approx 1:40 ratio fall.Have a look at this website www.pavingexpert.com ,click onto site index tab then scroll down to drains for more info (very useful website)
You can cut into the cast iron with a grinder starting with a ' V ' shape then cut into the back (make sure you got enough support brackets as they are heavy).Might pay you to change over plastic etc.Not sure if this applies to you but found this on the previous post :"If you are in a conservation area you may need permission to change from cast iron to plastic"
If you're keeping the cast iron soil pipe you can connect your existing soil vent with Fernco pipe connections which is suitable for Clay,Cast Iron,PVC-u,Steel,Asbestos Cement,Pitch Fibre and Concrete. Fernco is a flexible couplings can make easy work of an otherwise difficult pipe connection and size range in diameters from 1 1/4" to 15" and a reducer if needed.It is also BBA Approved and should be available from any good quality builder merchant.

 

[wjm]

Not excatly an answer as such, just thought it was worth mentioning,

Have a look here:

http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=37335&id=13126

It might be useful - it allows you to connect a toilet to a standard waste pipe.