Soil stack help!

Drodough

Hello, I just bought a new house and am planning to create an ensuite. I will need to have a new window installed. However, as the new window is going to be adjacent to the current bathroom, the proposed new window happens to fall in the section of wall the soil stack currently runs up. I have been googling to find the best solution and have 2 questions please:

1. The soil stack is cast iron. Can I add a ‘bend’ to the stack? I assume this will not be an easy job, as it’s cast iron—but is this ok to do? (Regs seem to suggest yes, but would like to check with someone who understands them better )

2. It has been suggested that I could add an external ‘durgo’ value, and cut the stack  off below the height of the window (but above the level the waste exits). However, I can’t find anything to confirm this is ok to do (I’ve found lots about internal use of durgos, but can’t get a definitive answer for my particular query). Is this an option? 

Thank you! 

ChasingtheWelshdream

I'm afraid I can't offer any help but will be interested in the answers as we are in a similar situation and I've just posted a question myself. We've had a couple of people say you can't connect into cast iron, and a couple who have said it's fine.  

We did have an en-suite added to our last house as part of an extension and we did not have a window. I personally prefer windows in bathrooms but it may be an option to forego this if it makes the actual drainage easier?

Mickey666

I have a cast-iron soil stack with two bends that enters the upstairs bathroom, which is jettied, at floor level.  All the bathroom waste pipes (toilet/shower/sink) are plastic and empty into a plastic soil pipe that connects into the external cast-iron soil pipe.  Finally, the plastic soil pipe it terminated inside the bathroom with a Durgo valve.  No problems.
External Durgo valves are widely available.

FreeBear

ChasingtheWelshdream said: We've had a couple of people say you can't connect into cast iron, and a couple who have said it's fine.

Pretty sure you can get fittings to connect to cast iron - I have in the back of my mind, a thread over on the Period Property forum where a similar issue was being discussed.

Myself, I had to replace the upper section of a cast iron SVP as the original was heavily rusted and full of holes. Removed the rotted section back to a joint, inserted a new (plastic) pipe and sealed the joint with mastic.

grumbler

Drodough said:

2. It has been suggested that I could add an external ‘durgo’ value, and cut the stack  off below the height of the window (but above the level the waste exits). However, I can’t find anything to confirm this is ok to do (I’ve found lots about internal use of durgos, but can’t get a definitive answer for my particular query). Is this an option? 

I am no expert, but...

"Air admittance valves should not be used outside buildings"

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/442889/BR_PDF_AD_H_2015.pdf - p.11

ETA: However, if the pipe obstructing the new window is purely for air admission, i.e. without any flow of water, I'd redirect it around the window without hesitation. It can possibly (not sure) be even a smaller diameter pipe at the top.

daivid

Is the house listed and/or in a conservation area, if so you will permission to add the window and very possibly to make alterations to the pipe. If not listed nor in a conservation area then replacing with plastic will make things easier and almost certainly cheaper too. Also: no the 'air admitance' part of the pipe does not need to be the same diameter as the 'soil' section; adaptors can be purchased just in a 'standard' situation using the same pipe all the way up is cheaper and looks neater, for the OP though stepping down may help.