110mm boss into soil stack

[Inchiquin]

Will a 40-110mm boss fit snugly into an old cast iron soil stack junction (presumably 4")? If it's too small that shouldn't be a problem as I can seal it, but if it's too big I'd rather not find out after I've dismantled the existing waste system.

Alan

 

[Deleted member 267285]

If you’re thinking of a strap boss, how do you expect to drill it?

 

[Hugh Jaleak]

Assuming I have read this right, then a 110mm plastic spigot into a 4" CI socket should be ok.

 

[Emit]

If you’re thinking of a strap boss, how do you expect to drill it?

I can’t make out what the op is saying but for future reference and a bit of ****ing about with a mechanical file or electric file like a dermal then use this after stitch drilling. Long process but can be done https://www.screwfix.com/p/mcalpine...EXi42os8wVZFJenJ2VBoCD8oQAvD_BwE&gclsrc=aw.ds

 

[Emit]

Can also use a very decent hole saw as well

 

[Inchiquin]

Sorry if I was unclear. I thought that "into a stack junction" would make it clear enough that there is already a junction into the stack so no drilling required. I want to replace an old lead bath outlet with 40mm plastic. Currently it's sealed into a 4" junction to the stack (presumably with lead). Since 110mm is slightly bigger than 4" I wanted to be sure that a 40-110 boss was likely to fit before I disable the existing pipe.

 

[Deleted member 267285]

Yes clear as mud I think I know what you mean now though, probably best with Hugh’s advice, or an adapter of sorts.

 

[Hugh Jaleak]

Might save yourself a whole world of pain if you cut the lead off as close to the stack as you can, but leaving enough of a stub to get a compression waste coupling onto, then going from there in plastic. Depends how neat you want it to look, and if you've asbestos hands I think.

 

[Nige F]

As Hugh says = a Mac Alpine compression fitting is the universal fitting one - lead/plastic 40mm