Kerdi-Line Outlet Mod

[RSquirrel]

The Kerdi-Line KL1V60E70 drain channel body has an integral outlet “collar” that is intended to be connected via a no-hub coupling to the inlet of an existing 2-inch drain. I am attempting to reduce the elevation of the drain body as much as possible to minimize the curb height for a shower remodel. By adding a 2-inch PVC elbow (shown in red in attachment) to the collar (shown in green), the elbow’s outlet can be connected via a no-hub coupling to the existing 2-inch cast iron drain inlet at its fixed elevation in the adjacent wall-space.

This arrangement results in a ~4” dimension from the top of the pre-sloped Kerdi shower pan to the center of the elbow’s outlet (see attachment upper image).

With a slight modification, an additional ~1” curb height reduction would be possible (every bit counts). The modification consists of shortening the metal14-ga. collar by 1”, which will then allow the top of the elbow to butt up to the bottom of the channel body (see attachment lower image). In case it’s relevant, I will be using a Schluter-authorized contractor to do my shower remodel.

Q. I assume this will void any Kerdi warranty, but that’s not my major concern, that aside, would there be any plumbing code issues with such a modification?

Q. Other than warranty and/or code issues, is there anything else I should be aware of?

 

[wwhitney]

What's your code compliant method for connecting a stainless steel 2" spigot end to a PVC hub?

Also, the elbow you have drawn is a vent elbow, that is not allowed for drainage.

Cheers, Wayne

 

[Sponsor]

 

[RSquirrel]

Hi Wayne,

Thanks much for your quick response. Your comments served to point out the two issues with my proposal (i.e. no approved connection method and a non-conforming drain component). I did some more digging and found a solution to both of these issues - a Fernco QL 200 90-degree no-hub coupling. Unfortunately it adds ~1-1/4" of curb height, but I can live with that. That leave only the shortening of the drain's collar as a deviation from the "norm." Since you didn't comment on the drain collar modification, I'm assuming that you have no issue with the modification (other than the potential for voiding Schluter's nebulous warranty) - see the new attachment . . .

 

[wwhitney]

Unfortunately, Fernco QL200 is not an acceptable solution to your issue. Per Fernco's website, the only standard it conforms with is ASTM D5926. That standard is not referenced in the California Plumbing Code Chapter 7 on Sanitary Drainage.

Sections 705.10.3 and 705.10.4 of the California Plumbing Code cover connecting dissimilar DWV materials when one side is plastic or stainless. They say:

"705.10.3 Plastic Pipe to Other Materials
Where connecting plastic pipe to other types of plastic or other types of piping material; approved listed adapter or transition fittings and listed for the specific transition intended shall be used.

705.10.4 Stainless Steel Pipe to Other Materials
Where connecting stainless steel pipe to other types of piping, listed mechanical joints of the compression type and listed for the specific transition intended shall be used."

QL200 is not listed for the specific transition.

So the proper solution is to use a Fernco 3000-22 banded rubber coupling (assuming this is above grade; if it is to be embedded in soil/concrete, you would use a 1056-22 or 1056-22 RC) to the street end of a street LT90 (or if underground, you'd need to use a regular LT90 and a section of pipe with 2" sticking out for the 1056 to engage with). Using the street end of a 2" LT90 is a slight cheat, as the straight portion is only 3/4" long, while the socket depth on the Fernco 3000-22 is 1", but seems OK.

If the spigot end on the Kerdi line is much over 1" long, and you are using a coupling like Fernco 3000-22 which only engages 1", I see no performance issue with cutting the spigot end to just over 1" long, as long as you properly smooth your cut edge.

I don't really see any compliant solution with the Kerdiline drain other than the Fernco 3000-22 and LT90. If that gets you too low (or, as I gather you are connecting to an existing trap arm at a fixed elevation, puts the drain body too high), I'd suggest looking at a different drain that lets you exit horizontally or at a 45. E.g. for a round drain (not a trough), Schluter®-KERDI-DRAIN-H. Or some other manufacturer may have a stainless trough drain with a horizontal outlet and a method for integrating with Kerdi.

Also, why do you need to turn horizontally immediately, rather than dropping directly into the trap?

Cheers, Wayne

 

[Breplum]

Dropping into the p-trap is the way to insure odors don't have a place to accumulate and make snaking the easiest.
Tight elbows will never allow snaking. offsetting with 45s are ok

 

[RSquirrel]

Unfortunately, Fernco QL200 is not an acceptable solution to your issue. Per Fernco's website, the only standard it conforms with is ASTM D5926. That standard is not referenced in the California Plumbing Code Chapter 7 on Sanitary Drainage.

Sections 705.10.3 and 705.10.4 of the California Plumbing Code cover connecting dissimilar DWV materials when one side is plastic or stainless. They say:

"705.10.3 Plastic Pipe to Other Materials
Where connecting plastic pipe to other types of plastic or other types of piping material; approved listed adapter or transition fittings and listed for the specific transition intended shall be used.

705.10.4 Stainless Steel Pipe to Other Materials
Where connecting stainless steel pipe to other types of piping, listed mechanical joints of the compression type and listed for the specific transition intended shall be used."

QL200 is not listed for the specific transition.

So the proper solution is to use a Fernco 3000-22 banded rubber coupling (assuming this is above grade; if it is to be embedded in soil/concrete, you would use a 1056-22 or 1056-22 RC) to the street end of a street LT90 (or if underground, you'd need to use a regular LT90 and a section of pipe with 2" sticking out for the 1056 to engage with). Using the street end of a 2" LT90 is a slight cheat, as the straight portion is only 3/4" long, while the socket depth on the Fernco 3000-22 is 1", but seems OK.

If the spigot end on the Kerdi line is much over 1" long, and you are using a coupling like Fernco 3000-22 which only engages 1", I see no performance issue with cutting the spigot end to just over 1" long, as long as you properly smooth your cut edge.

I don't really see any compliant solution with the Kerdiline drain other than the Fernco 3000-22 and LT90. If that gets you too low (or, as I gather you are connecting to an existing trap arm at a fixed elevation, puts the drain body too high), I'd suggest looking at a different drain that lets you exit horizontally or at a 45. E.g. for a round drain (not a trough), Schluter®-KERDI-DRAIN-H. Or some other manufacturer may have a stainless trough drain with a horizontal outlet and a method for integrating with Kerdi.

Also, why do you need to turn horizontally immediately, rather than dropping directly into the trap?

Cheers, Wayne

Hi Wayne,

I greatly appreciate the lengths you went to guide me down the right path. Based on your feedback, I've reluctantly decided to abandon the linear grate feature and stick with the Kerdi-H side outlet flange with the square drain. You have likely saved me a lot of grief, had I tried to pursue the other concept. Thanks again . . .