# Concrete Board in shower, need help please!



## floxy (Dec 17, 2007)

I just installed concrete board in a shower in preparation for tiling. I installed it with the smooth side out, but now reading more (which I should have done before) I'm thinking I should have put the rough side out. Can someone tell me if the smooth side will work or do I need to take out and redo. I really don't want to have to rip all of it out but I'd rather know now.

Thanks!


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## ponch37300 (Nov 27, 2007)

I know that the smooth side is for mastic which shouldn't be used in a shower and the rough side is for thinset. Can you use thinset with the smooth side? I'm not sure. Hopefully someone else will be along to answer that.


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## Ron6519 (Mar 28, 2007)

I never saw any insrtuctions relating to smooth vs. rough on the instructions pasted on the board. I wouldn't worry about it. But if you are, contact the manufacturer and ask them.
Ron

From the Durock website:
Dual surface texture - use mastics on smooth side for bonding material economy, and thin set mortars on the rough side for improved resistance to tile slip during installation. 

Shouldn't make any difference in the tile install. I use a ledgerboard for tile stabilization at the bottom, so the tiles aren't slipping anywhere.


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## ponch37300 (Nov 27, 2007)

This is a quote right from USG website for the durock brand cement board. Dual surface texture - use mastics on smooth side for bonding material economy, and thin set mortars on the rough side for improved resistance to tile slip during installation 

Here is the link, scroll down to find it. http://www.usg.com/navigate.do?reso...ts/prod_details/DUROCK_Brand_Cement_Board.htm


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## floxy (Dec 17, 2007)

Ron, thanks a lot for the help. I was hoping it was just a little more grip for slipping as well, but I'm planning to use a ledger as well.


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## AtlanticWBConst. (May 12, 2006)

Ron6519 said:


> I never saw any insrtuctions relating to smooth vs. rough on the instructions pasted on the board....


There's either a sticker or printing (dependant on the manufacturer) on every sheet of cement board that states which side goes outward (towards the tile).

There shouldn't be problem.
Tho, for others planning on installing cement board, they should try and adhere to the maufacture's instructions on this.


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## floxy (Dec 17, 2007)

I had an extra sheet and went back and looked at the sticker. Unless I missed it I didn't see anything stating which side should be out. I would think most people would put the smooth side out since it looks like the "finished" side. Thanks for all the help.


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## tverhoef (Feb 24, 2008)

I didn't see anything either...However I did ask my contractor before installing and I asked if it went like this ( smooth side out) he said it was fine, and it was inspected as well and passed with flying color, 
The inspector asked if I was gong to tile I told him yes he just said ok...had no problem.

oooppp's I found it...It's more like a MSDS lable but it states:smooth side mastic, rough side mortar. hmmm...I will think on this one and figure out the best way to handle this...I think I will be fine. I'm doing a walk in shower that is 4x7 so I hope its fine.

No worries I'm pretty good at improvising


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## tverhoef (Feb 24, 2008)

*Very glad for contractors*

After learning about the smooth side and rough on the concrete board I was thinking all that work.

so the solution I came up with was getting a product called Red gard "By Custome Building supply" I was going to roll the membrane on the cement board to create a rougher texture and this I know for sure would have worked...It can be applied to cement board and is ready for mortar tiling Glad it took the time to learn about special coatings over the years in the trades



floxy said:


> I just installed concrete board in a shower in preparation for tiling. I installed it with the smooth side out, but now reading more (which I should have done before) I'm thinking I should have put the rough side out. Can someone tell me if the smooth side will work or do I need to take out and redo. I really don't want to have to rip all of it out but I'd rather know n


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## McGaw (Sep 27, 2007)

Use rough. I always have for tiling. It will bond much better.


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## tverhoef (Feb 24, 2008)

*yes but I already used smooth*



McGaw said:


> Use rough. I always have for tiling. It will bond much better.


that was why I came up the idea in my last fourm message but thanks


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## McGaw (Sep 27, 2007)

Seems like it's just a waste of money to do that when you could theoretically take it off, flip it, and put it back on.


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## tverhoef (Feb 24, 2008)

*think about it*



McGaw said:


> Seems like it's just a waste of money to do that when you could theoretically take it off, flip it, and put it back on.


I have cuts that wont match up if I flip them and well I tend to think that my time is money. If you think about it I need to seal the seams anyway plus it just adds extra protection to the shower and will create a rougher surface for the mortar.

I was told by a contractor once you can never to to much when it comes to waterproofing inside a house.


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## McGaw (Sep 27, 2007)

Why wouldn't the cuts line up? If anything, it would be the screw holes.


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## floxy (Dec 17, 2007)

Here's the response I got from USG (manuf of durock)

" Yes you can install the smooth side out for thin set mortar we recommend the rough side because of the heavier texture it will accept more mortar in the texture."


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## McGaw (Sep 27, 2007)

So "It will bond much better" Is the same as what they're telling you.


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## tverhoef (Feb 24, 2008)

I don't know if your replying to my last message, but what the red gard will do is waterproof you seems and you can put it over your cement board and create a rougher surface for the mortar.


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## McGaw (Sep 27, 2007)

No, I was replying to Floxy.


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## Bill_Vincent (Feb 20, 2008)

Although the rough side will give you more area to grab, the smooth side can also be used..... even for thinset. Don't waste your money on Redgard, if the only reason you're using it is as a bonding surface. it's completely unnecessary, unless you were planning on waterproofing the cement board anyway.


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