Cast Iron Boss for 40mm waste

[Leonruss]

Hi All.

Apologies if this has been asked previously. I have searched for days but cannot find the exact answer.
I am installing a new shower room downstairs and need to connect the water waste (40mm) from the shower and basin. There is a 90mm cast iron soil stack right outside so this seems the best place to run my waste outlet to.

I know there are many options to connect to a 110mm pipe but the only Boss I can find to connect to 90mm is the McAlpine BOSS90TCAST-BL
The problem with this is it is made for connecting a condensate outlet so needs a 22mm hole. It doesn't sound sensible to reduce from 40mm to 22mm but there doesn't seem to be an appropriate boss for a 90mm pipe that a 40mm pipe can be connected too.

I know there have been suggestions of removing the whole stack and replacing with plastic but this seems like overkill to solve one connection. The other option I have come across is to cut a complete section out of the cast iron pipe and replace with plastic and then fit a boss but again I have not found anything for 90mm.

What other options are there? I would have thought a lot of old houses have 90mm stacks so would have been easier to find a solution but I have still not found anything that suites my situation.

Would appreciate any help!

Regards

 

[goz666]

McAlpine BOSS90TCAST-BL 1½" Pipe Mechanical Cast Iron Soil Pipe Boss Connector

Google that !!

 

[lame plumber]

next question, how to make a 40mm hole in cast iron

 

[PhoenixServices]

It's definitely a foul drain and not a rainwater one.

 

[PhoenixServices]

?....

 

[lame plumber]

?....

patience..

 

[Leonruss]

McAlpine BOSS90TCAST-BL 1½" Pipe Mechanical Cast Iron Soil Pipe Boss Connector

Google that !!

Thanks, however that is exactly what I have found but the McAlpine website says you need to drill a 22mm hole. I am connecting a 40mm pipe so that can't be the correct fitting.

 

[Leonruss]

It's definitely a foul drain and not a rainwater one.

Yes, the upstairs toilet, basin and bath all connect to the same pipe.

 

[goz666]

Thanks, however that is exactly what I have found but the McAlpine website says you need to drill a 22mm hole. I am connecting a 40mm pipe so that can't be the correct fitting.

The 22mm hole will be to accommodate the fitting in the pipe, the external fit is 11/2".

 

[Leonruss]

The 22mm hole will be to accommodate the fitting in the pipe, the external fit is 11/2".

Yes I understand that but then I will be reducing from 40mm to 22mm. That particular fitting seems to be for a condensate pipe:

From McAlpine website
"Additional Info: Pipe Boss Connector allows condensate discharge from condensing boiler to be discharged via cast iron soil pipe"

So would this be suitable for shower/basin waste? Would it even be according to regulation?
I spoke to two plumbing companies today. One said this boss is what I need, the other said its not the correct solution because of the 22mm hole so I'm just not sure if it will be OK or not.
I'm pretty sure the water will run away through the 22mm hole but it would be comforting to know if anyone else has actually used one of these for this situation?

 

[lame plumber]

wrong boss you want a 11/2 inch one as you say, plumbers merchant will have one, or a good one will, most nationals wont

 

[Leonruss]

wrong boss you want a 11/2 inch one as you say, plumbers merchant will have one, or a good one will, most nationals wont

The only boss I have found is 1 1/2 inch (40mm) external connection as suggested by goz666 but this requires a 22mm hole. I have not come across any mention of a boss that will require a 40mm hole that is suitable for a 90mm soil pipe.
The boss that needs a bigger whole is for the more standard 110mm soil pipe. I'm starting to doubt there is such a boss for a 90mm pipe but maybe it is hard to come by because the 90mm pipe is not very common but I just don't know who to contact to get hold of one.

 

[lame plumber]

try post 11 again as to where to look

 

[Leonruss]

try post 11 again as to where to look

Not quite sure what you mean. If you are referring to "plumbers merchant" I have tried a few one saying that part is OK and one saying it isn't. I came onto this forum to try find out if such a part is even available as if I can't find any reference to such a part maybe it doesn't exist.

Would local merchants have some sort of custom part? If it was available from a manufacturer wouldn't I have found a reference to it? Believe me I have searched online for many hours so just knowing if this type of fitting is even possible would help a lot at this stage.

 

[lame plumber]

like i mentioned a good independent merchant will have staff that know the stock, fm memory though the internal bit is smaller to allow for the mechanical attachment to the soil pipe, just need an 11/2 female on other side, unless you can lead weld/seal your not going to be able to avoid a drop in internal size

re online search, expertise is often found the old way as computer nerds dont work in cast iron now