Soil stack update for ensuite and bathroom remodel

[NickB_99]

hi,

This may be the first of a few posts along the way!

I want to add an ensuite into one of my bedrooms by taking a slice off against the outside wall. Stud wall etc.
It will be well located for soil stack access and also hot/cold water supply etc. The boiler is in the garage, right below.

The current soil stack is cast iron and I'm after some advice how to accommodate best what I'm trying to achieve.

The current main bathroom is to the left, and when it gets updated later I'd like to move the loo a short distance to the side, as shown below.
I'd like to get the ensuite fully working before tackling the bathroom so we keep working wash facilities.
I'm wondering if it's possible to update the stack (with at least some in plastic) and incorporate the waste from ensuite loo whilst supporting both the existing and new positions for the main loo?

Is it necessary to disturb the base of the stack or is joining higher up ok?

Some pics:-

Soil stack base, with downstairs loo

IMG_3441

• NickB_99
• 14 Mar 2017

Soil stack and approx locations of ensuite and main bathroom plumbing

EnsuiteStack

• NickB_99
• 25 Apr 2017

Thanks!

 

[muggles]

You need a Fernco coupler to adapt it to plastic. It's notifiable to Building Control so you should discuss your plans with them prior to carrying out any work

 

[Hugh Jaleak]

To be honest, I'd replace the lot with plastic, it's going to be much easier when you want to add connections and move the existing WC.

I'd be wary of cutting in mid way, cast is extremely heavy, and can rely on the structure of the pipework to some degree to support the weight above. For the sake of £100 I'd take it down, and replace it.

 

[NickB_99]

To be honest, I'd replace the lot with plastic, it's going to be much easier when you want to add connections and move the existing WC.

Would you recommend joining the plastic into the cast iron connector at floor level or take that out and replace that too with plastic?
Wary of damage.

 

[NickB_99]

The other relevant pic is the stack passes through the roof

IMG_3443

• NickB_99
• 14 Mar 2017

 

[Hugh Jaleak]

As its all encased in concrete at floor level, go from a suitable point between the branch for the ground floor WC and the point where you need to couple the new pipework in. If you can get the joint apart level with the outside light in the pic, that would probably be ideal, assuming the pipe below that point is sound.

Once old pipe is (carefully) withdrawn from the hole through the soffit and tiles, the new pipe should go through the same hole, although the weathering slate will probably need changing for a new version that will seal around the plastic pipe. Make good the hole in the soffit with silicon or similar.