Moving a toilet and a soil pipe - technical advice needed!

[dodgem]

Hi all,

I want to move a toilet in a ground floor flat by about 8 meters from it's original location, and further away from the manhole it drains into.

This will make the new toilet about 10 meters from the manhole.

I checked with Thames Water and seems this manhole might connect to a manhole in the neighbours garden 2 doors down, which then connects to Thames Water sewage at the front of the house.

Thames Water want 100mm clearance around any new pipes, and allowing for a 1:40 fall, means I need to dig a deep trench about 600mm at it's deepest point (below the internal floor finish level) and hope it can connect to the waste pipe system inside the existing manhole at the right level.

Questions are:
1) What are the chances the new soil pipe can connect to the existing manhole?
2) Anyone know what level top of the footings/foundations in early victorian houses generally is? I.e. What are the chances the new soil pipe avoids the existing footings/foundations - or go through them?
3) As it's a 10 meter run, do I need rodding points under the floorboards?
4) What do you think the cost of doing this is?
5) Any key questions I'm missing?

Look forward to your help!

 

[plastic_peanut]

There are a lot of questions here:

Do you intend routing the new waste pipe into the existing down pipe or creating a new downpipe?

 

[Ian H]

You need to decide where you are going to make your downstream connection, find out the depth of that and see if you have 20cm off fall between there and where your new rest bend will be.

Could you not go outside with it?

 

[Nige F]

As often said on the forums -Pictures please ?

 

[dodgem]

I want to move the bathroom from the back to the front of the flat - as i want the kitchen and living room overlooking the garden.

The old rest bend/downpipe is on the other side of the old toilet wall outside. I don't know how deep into the ground it goes.

The new toilet will be 8.5 meters further away from the old toilet position.

So far I'm thinking I have a couple of options (I may be wrong)

Option 1:
Run a new soil pipe from the new toilet above the floor, around the flat, and box it out till it meets the existing rest bend - and hope it meets it at the right level and doesn't end up lower

Option 2:
Run a new soil pipe from the new toilet, under the floor through the flat, till it meets the existing rest bend - and hope it meets it at the right level and doesn't end up lower.

If the new soil pipe ends up alot lower than the existing restbend, for both options, I would check if the waste pipe in the manhole is lower than the existing rest bend and try to make a new connection to the manhole instead.

Just wondered if I'm missing something - or if these sound like sensible options?

 

[Ian H]

Can you shine a torch down the pipework to see how deep the rest bend is?

 

[dodgem]

Please see attached photo.

I would need to disconnect the SVP pipe.

I'm about to buy this property and only really want it if I know I can move the toilet.

I may be able to look into the manhole next time I go for a viewing.

 

[Hugh Jaleak]

First thing you need to establish is depth of existing drain, unless you can get the required fall, (slope), on the new drain run, your idea is a non starter. Water etc doesn't run uphill.

If the required fall can be achieved, you will need to be able to run in a straight line, (under the floor), from the connection point onto existing sewer, to the proposed new WC position. Forget any ideas about running pipes around walls, it's unlikely you'll be able to get a straight run, bends will only increase the risk of blockages, and the last thing you want to be doing is dismantling/cleaning out a blocked soil pipe inside the property....

If you're not sure either get a Builder to look, or look for another flat, this is not a job you can afford to get wrong.

 

[dodgem]

Thanks for your feedback.

Will check level of the existing drain level.
Hopefully the manhole cover can be easily lifted.

I have seen other jobs, run the waste pipe around a flat on top of the floor (boxed in with access points every 3m) - and have it get signed off by building control, so I know it can be done that way - but I agree that it's a rubbish solution.

 

[Leofric]

Will check level of the existing drain level.

Good start