# Connecting ABS to Cast iron....



## pzeiler (Apr 2, 2010)

Just brainstorming....I'm trying to figure out if there's a way to connect 1-1/2" ABS Vent line running horizontally TO a 3" cast iron existing vent running vertical. I've never encountered this situation. Suggestions?? Thanks.


----------



## rex (Jul 2, 2007)

most "GC's" round here would use a 3" fernco T and some bushings...


----------



## griz (Nov 26, 2009)

Don't brainstorm too hard or too long.
Stock items at the plumbing house.
Heck, hardware store has this stuff.
Cut in a 3" x 1-1/2" San-T & glue it together.
Why you mixing ABS with cast?


----------



## Smatt (Feb 22, 2011)

Make sure your cast iron is supported well before you cut. I prefer no hub bands myself.


----------



## pzeiler (Apr 2, 2010)

griz said:


> Don't brainstorm too hard or too long.
> Stock items at the plumbing house.
> Heck, hardware store has this stuff.
> Cut in a 3" x 1-1/2" San-T & glue it together.
> Why you mixing ABS with cast?


 
Existing through roof vent is 3" or 4" cast. I don't want to have to redo the through-roof penetration, but I do want to tie into it. I just haven't had to do a connection like this before, nor seen one. So you're saying to cut the cast above and below the fitting, then insert the San T? Thanks!


----------



## KillerToiletSpider (May 27, 2007)

Cut in a cast iron tee and yarn and pour the ABS into it. It's not rocket surgery.


----------



## psolutions (Jun 15, 2009)

We would use a no hub band with a bushing.


----------

