Simple Kerdi Drain Question . . . [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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02-12-2010, 01:45 AM
I am in the middle of a remodel of my master bath down to the studs. The 60-year-old house has a perimeter foundation, plywood subfloor [original 5/8" + 3/8" I added] on 16" joists with accessible crawlspace. I am installing a Kerdi shower and have already ordered the 2" ABS drain. This area still has strong trade unions that have influence on the local building code and among plumbers and inspectors, PVC and ABS are persona-no-grata. Accordingly, my plumbers roughed in 2" copper drain pipe for the shower. When they completed the job, they left behind a very substantial-looking traditional cast iron drain. When I received my ABS Kerdi drain in the mail, I have to say I was somewhate disappointed. It looked downright wimpy compared to the cast iron one. Questions:

1. Is there a Kerdi stainless steel drain that would fit my application? I.e. is the "KDAR/ABS/E Residential floor drain adapter kit with stainless steel intergrated bonding flange" what I am looking for? [I can't find a picture or further description of that product on the internet and I suspect it is partly made of ABS.]

2. If not, do I have any reason to be concerned about the durability of the ABS drain? This is the last showerpan I plan to do in this bathroom in this lifetime.

3. How do I attach my ABS drain to the 2" copper pipe? Glue? Neoprene connector?

This is my first post on John Bridge and I look forward to your informed advice.


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02-12-2010, 02:13 AM
This area still has strong trade unions that have influence on the local building code and among plumbers and inspectors

:cry:Don't get me started....

But to your questions. I wouldn't worry about the durability issue. IMO pvc hold up better over time than cast iron, on of the benifits of being non-biodegradeable and non oxidizing I guess.

As for connecting it, my guess would be a metal sleeved rubber connector from the copper to a small section of pvc pipe, which is then connected to the drain. But that is just a guess. You might want to post this question at Terry Loves's plumbing forum. But there maybe someone that will come along and give a definitive answer.

Dave Taylor
02-12-2010, 02:36 AM
Hi and welcome to Tile Your World forums, John.

I merged and deleted your dup threads.

Carry on. :---)

02-12-2010, 11:38 AM
Have you checked to see if they will approve Kerdi in the first place? Seems if they are that tied to old-school that they may not allow it?

02-12-2010, 11:38 AM

Thanks for the advice. I searched the Terry Love plumbing site and could not find anyone with the same issue on a Kerdi drain. Generically, there are some who discuss connecting PVC/ABS to iron pipes using a rubber collar. My only concern with is whether the collar will last as long as the ABS and copper. In hindsight this might be a better question for the plumbing forum. If I can't get an answer here, I'll have to sign-up at Terry Love and put the question out there. Thanks,


Thanks for cleaning up my repost. Still not sure how I did that.

02-12-2010, 06:43 PM
The connection can be made with a Fernco Fitting. There are several available and any decent plumbing supply house can get them for you.

Have no fear about the Kerdi drain. It'll be around a lot longer than you will!

02-12-2010, 06:52 PM
Ditto.. A Fernco (brand name) is acceptable, and will outlast you. You'll need a short section of 2" ABS to glue into the Kerdi drain, and then use the Fernco to transition to the copper.

02-12-2010, 11:25 PM
Alex and Laz,

Thanks for the advice and the reassurance. I will go with the Fenco sleeve.


Yes, Kerid is allowed. Go figure . . .

John Griffith
02-13-2010, 03:11 PM
I have a similar problem. I am about to install the Schluter shower tray on a concrete slab. I am replacing an old fiberglass one-piece shower, so the drain is already installed, with the 2" PVC pipe stub solvent-glued in place. I am hesitant about gluing the Schluter drain stub directly onto the existing PVC drain, so can I use the rubber sleeve mentioned above to make the transition? Will it be as water-tight as the Schluter system purports to be? Any other caveats of which I should be aware?

Houston Remodeler
02-13-2010, 03:20 PM
Yes, a mission / fernco fitting will be equivalent to gluing it in place. Can you get a screwdriver in there to tighten the rubber fitting?

John Griffith
02-13-2010, 03:25 PM
Yes, I've never used the Fernco sleeve before, but if it isn't over 3 inches tall, I think I can get to it with a screwdriver to tighten the bands. The concrete floor is broken out about 10 inches around the drain, and it's about 6 inches deep. I should be able to install the Fernco sleeve,with a short PVC stub on top to glue to the drain hub. It's just that I was hesitant to glue the drain directly to the waste stub, since I would never be able to change it out after that.

Houston Remodeler
02-13-2010, 03:32 PM
There are these nifty little tools to remove a drain that is glued into place. It fits into any drill, available at big box store.

John Griffith
02-13-2010, 04:18 PM
Well, this tool may relieve my fears, then. But again, I don't ever expect to need to remove this shower floor in my lifetime ( I'm 66 yrs old). I was just thinking of the next fellow who may want to remodel this bathroom after I'm gone.

Houston Remodeler
02-13-2010, 07:07 PM
Then glue it together. It should be what he is expecting.