# Is a mud deck always needed for Kerdi drains?



## quick72toy (Feb 4, 2013)

Have a bit of a dilemma, working on a Bsmt shower. The concrete was poured with a pre-slope, so I'm wondering if I can just use a layer of thinset and place the kerdi drainflange over it, and then apply the membrane over that, or do I have to use a mud deck with the Kerdi drain? Really don't want to lose any ceiling height by having to add a mud deck. 

Sorry to open Pandora's box here, but also wondering about liquid membrane alternatives (Hydroban, Aquadefense, Redgard,) and what proper drain setup that can be used with them without having to go the deck mud route. 
Open to all suggestions.

Thanks


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## astor (Dec 19, 2008)

If the shower floor is sloped to the drain, you do not need mud, you can just use Kerdi Drain and membrane over. I use Noble TS or (Dal Tile TS) membrane which is thicker.
Here is a pic of my project that looks like yours.
Some likes liquid membranes, but if you have new wood studs, you have to consider movement.


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## JazMan (Feb 16, 2007)

You don't need another deck mud but you're gonna have to feather out from the outer edge of the Kerdi drain out. It'll work if there's enough slope, and 1/2" per ft. is good. Do a dry fit and see.

Jaz


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## quick72toy (Feb 4, 2013)

Thanks astor and JazMan for the pics and advice. 
Test fit a Kerdi drain yesterday and the slope is good, but I will have to feather out from the drain edge as you said. 
Is it okay to use thinset for this?


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## skyhook (Mar 17, 2007)

The reason for deck mud is to make the floor level with the world. If it's not level, the user could experience vertigo and fall down, promting your GL policy to kick in.


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## Aaron Tritt (Feb 4, 2011)

1/2" of fall per foot is the maximum allowable slope in a shower by code in my area. 1/4" per foot is miminum.


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## astor (Dec 19, 2008)

quick72toy said:


> Thanks astor and JazMan for the pics and advice.
> Test fit a Kerdi drain yesterday and the slope is good, but I will have to feather out from the drain edge as you said.
> Is it okay to use thinset for this?


Thinset would work since it is a small area, or you can get a bag of Mapecem for $7, feather and keep working as it is fast dry.


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## world llc (Dec 9, 2008)

or use cup grinder (and vac attachment) and grind down the little needed to flush the drain


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## quick72toy (Feb 4, 2013)

world llc said:


> or use cup grinder (and vac attachment) and grind down the little needed to flush the drain


 You must hve been reading my mind. Just did that today! LOL


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## world llc (Dec 9, 2008)

quick72toy said:


> You must hve been reading my mind. Just did that today! LOL


glad it worked out, please continue to post progress pics!!


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## quick72toy (Feb 4, 2013)

Drain is in.


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## ohiohomedoctor (Dec 26, 2010)

Is that a steamer or a toe blaster?


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## quick72toy (Feb 4, 2013)

Toe blaster


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## ohiohomedoctor (Dec 26, 2010)

Nice!


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## skillman (Sep 23, 2011)

quick72toy said:


> Toe blaster


That's high class . .


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## ohiohomedoctor (Dec 26, 2010)

Until you blast your athlete's foot and it becomes pink eye...


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## world llc (Dec 9, 2008)

look'n good, quick!


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## nhill2090 (Dec 11, 2010)

1/2" per foot in that shower you could break out your snow skis


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## astor (Dec 19, 2008)

quick72toy said:


> Toe blaster


:no:Nope it is not genuine toe blaster, to call it _*real*_ "toe blaster" it's gotta be made of bricks ----like mine..:laughing:
once you hit, the whole neighborhood should know


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