Cast iron main stack, need to connect toilet waste pipe, please help
Anonymous user 03/03/2024 - 2.56 PM
Hi, i am fitting a new bathroom in my house next month and need some advice before i purchased the items i need, the main stack is made out of cast iron, and the new toilet pipe is make from plastic, i need to attach the toilet waste pipe to it is there some sort of sort strap boss that i can get to attach to the main stack? really want to avoid replacing the main stack with plastic.
As there is already a toilet waste pipe connected to the left of the main stack and the new toilet is going on the right side of the main stack and i cant use the old toilet waste pipe can i cut it down and block it off??
Am also looking at putting in a new shower, the pipes will be behind tiles, where do put the isolating valve or should i not bother.
Thanks in advance.
Tim
Thanks for your help, just wanta be sure in what I'm doing as this is my first time doing this but it wont be the last I'm sure, as I go to college part time and study plumbing,
Do you have a link where I can see a picture of this,
Are you a tradesperson and able to answer this question?
Hi Tim, afraid I don't know of any boss to go in cast iron, fairly sure it doesn't exist. I do know of large black rubber straps that fit around the cast and new plastic soil, you could cut out section going to the left fit new plastic branch going towards desired location and use the black rubber straps either end. They have adjustable jubilee clips to create seal and as they go on the outside they do not restrict flow. I personally wouldn't bother with valves as it sounds like they won't be accessible if pipework is either under the floor or in the wall. Hope this is helpful. David
time saver,cut out existing branch with angle grinder support stack above,fit new time saver branch with iron collars supplied with branch,you could use the rubber connectors with plastic branch between, but with cast iron above you could have a problem of weight above,old cast iron stacks are nailed to wall through the ears on them and often come loose leaving all the weight above on rubber and plastic you could of course renew whole stack there are also strap bosses you can use on cast iron soil stacks,try to put isolation vales in if you can you may be able to install them in a duct or where they enter the room.
A cast iron ‘strap on boss‘ is available for this situation- they’re only stocked by specialists, but you’ll find them on google. They are quite expensive! Be careful not to over tighten, cast iron not great in tension and you can easily crack the strap.
Hi,
you can find adaptors from cast iron to pvc, if you search on google harmer,ensign, saint-gobain, all cast iron you can find exactly what you need. If you want to use the same drainage for toilet and only changing the orientation it's easy depending what kind of cast iron you have installed one it's with coupling and screw or with rubber have a look. A picture will help to see and understand better the situation.
unfortunately there is only one answer to this that will future proof all other works that you plan. McAlpine do a cast to plastic adapter that allows you to move to plastic 110mm. Its a simple process of cutting out the cast at low level then insert the adaptor then replace you entire stack.
