# Granite shower curb



## Xtrememtnbiker (Jun 9, 2013)

So after the thread where Spencer asked about how people handle the top of the curb on a shower and quite a few of you guys mentioned granite, we are trying that on a job right now.

My questions is how do you attach the granite? I have kerdi fix for doing niches Angus style and thought I could do a cris cross pattern of that but I didn't know if that would support it or should I just use thinset?

And while you're reading anybody have a trick for pre-sloping a kerdi curb on top without just tilting it which messes up the sides? I plan to slope the granite with a shim that I will rip.

Thanks guys.


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## TAHomeRepairs (Jun 18, 2012)

I've always just used thinset to attach granite curbs. I also use the mud to create the pitch, just build up the mud bed on the outside.


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## angus242 (Oct 20, 2007)

You should preslope the curb itself, never use thinset to create a slope. Thinset is not waterproof. Therefore, any moisture that does get under it doesn't have a slope to pitch it towards the drain.

To pitch a Kerdi curb, I just put a slight tilt on my table saw and run the foam through. Yes it's messy but for that 30 second task, you are done.

To adhere the granite to a membrane, put a skim coat of thinset on the curb, let it dry and silicone the stone to the curb.


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## Xtrememtnbiker (Jun 9, 2013)

angus242 said:


> You should preslope the curb itself, never use thinset to create a slope. Thinset is not waterproof. Therefore, any moisture that does get under it doesn't have a slope to pitch it towards the drain. To pitch a Kerdi curb, I just put a slight tilt on my table saw and run the foam through. Yes it's messy but for that 30 second task, you are done. To adhere the granite to a membrane, put a skim coat of thinset on the curb, let it dry and silicone the stone to the curb.


That makes a lot of sense on the slope issue. I will do that. So just 100% silicone no need for kerdi fix?


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## angus242 (Oct 20, 2007)

Kerdi-Fix is badass, no doubt. I'm just not 100% sure what it will do to the stone (will it seep in and stain?) Just go with what the stone installers use on millions of successful installations. 

Most important is to preslope your curb BEFORE you add any waterproofing, skim coats, etc.


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## Xtrememtnbiker (Jun 9, 2013)

angus242 said:


> Kerdi-Fix is badass, no doubt. I'm just not 100% sure what it will do to the stone (will it seep in and stain?) Just go with what the stone installers use on millions of successful installations. Most important is to preslope your curb BEFORE you add any waterproofing, skim coats, etc.


Sounds good. Silicone it is.

At your recommendation on the slope I pulled the curb yesterday, ripped it 3° and re-installed it. I'll wrap kerdi and skim it before installing granite.

I should go ahead and say thanks to you now that your back. I've read 100's of your posts and learned so much more about tile than I knew. Thanks for all your advice you give on here!


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## rrk (Apr 22, 2012)

Another way to get the slope is to layer 2" and 1" strips of kerdi before covering the curb with kerdi. If you dont have a table saw handy


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## nhill2090 (Dec 11, 2010)

why wouldn't you just use thinset? Would you use silicone to install granite tiles?

I use thinset for granite marble and quartz curbs. works fine


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## cath8r (May 2, 2014)

I've always used thinset and u spacers to get theright slope and then siliconed the joints on top of the grout after it cured.


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## bowtie (Feb 4, 2012)

nhill2090 said:


> why wouldn't you just use thinset? Would you use silicone to install granite tiles?
> 
> I use thinset for granite marble and quartz curbs. works fine




I would pass on the silicone too, it has to compress somewhat ... thin set will not ...


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## angus242 (Oct 20, 2007)

Does anyone use thinset to set granite counter tops?


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## rrk (Apr 22, 2012)

Nope


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## angus242 (Oct 20, 2007)

Boom!


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## bowtie (Feb 4, 2012)

I use thinset on granite tops, 12x granite tops ... Don't think I'd ever use silicone for that either ...


Boom ...


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## angus242 (Oct 20, 2007)

Ah, so you're a 1%er


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## Xtrememtnbiker (Jun 9, 2013)

I used silicone cause angus said to...

For the sake of learning though, why would you use that over thinset angus? Because of an adverse reaction to the granite?


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## angus242 (Oct 20, 2007)

I don't install slabs. The stone installers that I've used (many 4-5 different ones over the years) all use silicone. If that's what the pros use, why would I question that?

But yes, the biggest reason I wouldn't want to use a thinset would be the potential reaction. Especially with a lighter colored granite, I would worry about possible staining from underneath rising up to the surface.


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## Xtrememtnbiker (Jun 9, 2013)

So does that mean you don't use granite curbs? Or you just don't install them yourself?

That's pretty much what my reaction was, Angus (the pro) says use it. So I did, and it worked great.


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## angus242 (Oct 20, 2007)

I don't install them. If they are used, the granite guys do the install.


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## Eaglei (Aug 1, 2012)

Silicone is not an adhesive , it's a sealant . If your going to go that route I would use phenoseal , it's a sealant and adhesive in one . It can also be used to hold down granite tops . I would use thinset to install a granite curb just as I would use thinset to in stall a marble or granite door saddle .This was how I was taught and believe it's done this way in my neck of the woods . As far as being the 1 % I guess you can say it's how you were taught or how it's done in your neck of the woods .


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