# cement board &shcullter system



## bbgcarpentry (Apr 11, 2009)

My dry wall guy put up the cement board with dryall screws,i know should use the green special screws but before the tiler tiles the shower enclosure he is waterproofing all the walls with the schulter waterproffing orange membrane.My thinking is as its going to be waterproffed i should let it go that theres drywall screws.But my tile guy has slagged off the drywall guy to my customers dad?what do you think???


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## rselectric1 (Sep 20, 2009)

Uh Oh! I'm afraid you just laid the groundwork for WWIII here.:laughing:


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## Splinter (Apr 5, 2005)

I believe the issue is the alkalinity of the cement board corroding the drywall screws. Does it really? I dont know... In my area of the country, I've pulled out a few cement board showers with drywall screws, and the screws were in decent shape. I suppose it's a gamble. What's a box of the greenie's cost? 

Oh, you'd better correct your spelling of Schluter... Angus get's very defensive about such things... 

(kidding A-)


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## TileLady (Apr 8, 2008)

Well it would probably be fine but it does void warranties for both products I'm sure.

So......


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## Static Design (Nov 30, 2008)

I thought the membrane could go directly over the drywall? Why add cement board if it's not needed?


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## bbgcarpentry (Apr 11, 2009)

*your wright*



Static Design said:


> I thought the membrane could go directly over the drywall? Why add cement board if it's not needed?


 
my customer wanted it even though i told him is was not needed,13 to 14 hours a day working scrw the spelling?

so its the alcaline that could damage the screws, i like my drywall guy and just thought the tiler was out of order slagging him off.


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## angus242 (Oct 20, 2007)

The use of alkali-resistant screws is so there isn't a chemical reaction between the thinset and the metal. Not sure how long this corrosion takes to occur.

If guys are still putting tile over 3/4" subfloors, not using vapor barriers with CBU in showers and using mastic in wet locations...I don't really think the world's gonna end on you.


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## angus242 (Oct 20, 2007)

Splinter said:


> Angus get's very defensive about such things


_*
Yeah....what the F is &shcullter*_?

:furious:    :wallbash::thumbdown:ban:


That's just plain offensive..


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## angus242 (Oct 20, 2007)

Splinter said:


> Oh, you'd better correct your spelling of Schluter


I think even RS is offended....:whistling


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## rselectric1 (Sep 20, 2009)

angus242 said:


> I think even RS is offended....:whistling


I sure as heck am! I hate bad spelling.:laughing:

OMG what am I doing up this late?

Hint-day off tomorrow so I will be littering the forum with my usual smack---only earlier!:clap:


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## Static Design (Nov 30, 2008)

Why are people still using cement board if using schluter?


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## WarnerConstInc. (Jan 30, 2008)

that was denshield.


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## Splinter (Apr 5, 2005)

angus242 said:


> :furious:    :wallbash::thumbdown:ban:


Wow! you'd even ban the dude for that, eh? You ARE hardcore Schulter... I mean Schluter....


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## angus242 (Oct 20, 2007)

Splinter said:


> Wow! you'd even ban the dude for that, eh?


:blush:


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## NorthernSails (Apr 7, 2010)

You do need an alkai-resistant screw if you work with cement because drywall screws will react with the product (I think the screws react with the board and not the thinset but I could be wrong). Oddly enough I was just talking about tile backers in another thread but I don't use cement board anymore and I use a product called GREENE-BOARD. You can use regular drywall screws with this product and they don't react with the board.

It's almost redundant placing a tile backer behind the Ditra system but I think they do recommend it. I love the system but damn it can be pricey.


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## angus242 (Oct 20, 2007)

NorthernSails said:


> (I think the screws react with the board and not the thinset but I could be wrong)


Cement is alkaline. There is cement in thinset. :thumbsup:


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