Capping off Cast Iron Stack Bosses to Prevent Backing up and Flooding

Postby birdman » Fri Aug 08, 2014 5:12 pm

Hi All,
Living as I do the ground floor flat of a tenement I am constantly getting flooded out with waste water backing up into both the kitchen sink and wash hand basin in the toilet which are plumbed into a cast iron waste stack that also takes waste water, I woulld like to cap off the two bosses on this stack within my property after re routing waste pipes from washhand basin in toilet to the bath waste (which in turn is plumbed into its own seperate waste pipe) and the kitchen sink out through the wall to externally connect into the cast waste which only takes the bath waste from my flat.

Can it be done and what do I require to cap of these two bosses?

appreciate the replies guys.
Rank: Apprentice
Progress to next rank:
Posts: 5
Joined: Sat Feb 15, 2014 12:45 pm


Simply Build It

Postby thedoctor » Wed Aug 13, 2014 8:39 am

Hi. As long as you have a viable alternative to getting the waste water out the pipes can be capped off by cutting them off about 2 inches from the stack and fitting a solvent weld access pipe fitting. This has a screwed end which will remain watertight but still allow access to the trap for some "poking about" if a blockage occurs. Hope this helps, please do let us know how you get on.
Posts: 2298
Joined: Sat Apr 08, 2006 12:15 pm

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides

  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!


  • Related Topics