# Shower has drywall (not green) can I install Cement board Right over it?



## angus242

You should rip out the drywall and add 1/2" cement backer board. You are talking about a wet location here. You don't want to start cutting corners at this point when you have the opportunity to do it correctly. Even after the cement board is up, depending on your finished wall material choice, you need to consider waterproofing the area also.
If you decide you are going to do this correctly, post back and myself or the other knowledgeable people on this site will help direct you to the _proper_ way to build a shower wall.
Maybe even look around the flooring/tile section to see what other have already been through.


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## jwhiteuwc

Good point, why cut corners. I'll get the backboard.

For sealing it do you recommend hydroflex and trippleflex?


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## Termite

Definately a good move to get the rock out of there and properly install backerboard. Be sure to tape the seams and corners with mesh tape and mud them with thinset mortar to prevent grout joint cracking.

As for waterproofer I'd suggest RedGuard. It is very easy to do because you simply paint it on. On the higher end is Kerdi by Schluter, which is an easy way to a perfectly waterproof shower.


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## Sir MixAlot

jwhiteuwc said:


> *Shower has drywall (not green) can I install Cement board Right over it?*


Remove the regular drywall and install 1/2" cement board.:yes:


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## mikey48

What type of shower are you installing? Tile fiberglass or what?


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## 4just1don

I see those 'flip' shows every saturday,,,putting expensive tile on regular sheetrock,,,I CRINGE. They dont use poly,,they dont use redguard or ANYTHING else!!!


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## AtlanticWBConst.

My Vote: Remove and replace with 1/2" CBU (aka - _Cement Board_).


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## jwhiteuwc

Thanks everyone. I do have one last question.

Regarding the flooring (not in shower). Currenlty it has 12x12 Vinyl Tile flooring. I play on ripping that up and my guess is it's either subfloor or another type of vinyl floor under it. Should I:

A) Durarock the floor
B) Use Schluter Ditra for the floor. Look like it's roled out and a thin-set used under the ditra. Room is only 8x8 so my guess is either should be fine. Home is about 100 years old, so it's Settled already 

C) What does everyone use to cut the durarock? Diamond blade or something else? I thought I saw something by irwin or just some cement cutting skill saw blade?

Thanks for any information.


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## Baron

Dura rock is great for ceramic tile but other products are fine for inlay or vinyl tile.

I have used a utility knife, scored both sides, for Dura rock but yes I think I saw a blade for it.
Any cuts I have done have been with my 3 1/2 inch grinder with a diamond blade.


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## angus242

jwhiteuwc said:


> Thanks everyone. I do have one last question.
> 
> Regarding the flooring (not in shower). Currenlty it has 12x12 Vinyl Tile flooring. I play on ripping that up and my guess is it's either subfloor or another type of vinyl floor under it. Should I:
> 
> A) Durarock the floor
> B) Use Schluter Ditra for the floor. Look like it's roled out and a thin-set used under the ditra. Room is only 8x8 so my guess is either should be fine. Home is about 100 years old, so it's Settled already
> 
> C) What does everyone use to cut the durarock? Diamond blade or something else? I thought I saw something by irwin or just some cement cutting skill saw blade?
> 
> Thanks for any information.


Settling isn't the issue, it's deflection. That's the amount of "bounce" your floor has. Your joists will have a certain amount of movement and so will your subfloor material between the joists. If you post the following information, we can get an _estimate _to what your deflection ratio is:
Joist size (2" x 8" ?)
Spacing of the joists (measure from center to center of each joist)
Overall unsupported length (the joist will rest on 2 supports. What's the length between each support?)
And finally, if you can tell what species of wood it is and how good do they look. Are they a lot of holes cut through them?

If your specs come out alright, you should remove the vinyl and whatever underlayment is has. Basically, remove any material down to the subfloor. Now find out what your subfloor is and it's thickness. Ideally, you'd like to have around 1 1/8"-1 1/4" of material before you tile. You may have to install a layer of exterior grade plywood over your subfloor to stiffen it up.

As for your tile underlayment, I'd recommend the Ditra or CBU. Nothing wrong with CBU but I feel Ditra is a superior product. If you don't mind the added expense, I'd use that.

Durock and be scored and snapped with a carbide knife. 








and yes, you can get a cement backer cutting blade for your circular saw. I CANNOT TELL YOU HOW DUSTY THIS METHOD IS!!!! Protect your lungs and only cut outside!


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## jwhiteuwc

Thank you very much for that information. I'll check out the subfloor and see what needs to be addressed. 

I think I'll also go with the scoring tool, thank you.

-Josh


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## jwhiteuwc

Well everyone, i have all the board (densgaurd) up and am curious. I'm hiring a guy that is layed off to install the tile as he's a brother-in-law of a friend. My quesiton is, do I need to:

Fill in all the seems on the board before the installer arrives, or does the installer typically do this? 

If I have to do it before he arrives, do I fill it in with thinset?

I currenlty used Densegaurd in the shower, more info here: http://www.gp.com/build/product.aspx?pid=6388 

Thanks!


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## Blondesense

Brother-in-law of a friend!?!  What is his experience with tile? 

Seriously, I'm here reading these boards doing research for a similar project I'm planning this spring. 

If I were in your shoes I would be asking him your questions. Also ask about waterproofing. If he doesn't know, or worse yet, doesn't know what you are talking about you probably don't want to go there. From what I've read this is one area you really want to make sure is done right, and that anyone you hire knows what they are doing.

I'd rather (mess) something up myself, than have to pay someone else to (mess) it up for me!


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## jwhiteuwc

Blondesense said:


> Brother-in-law of a friend!?!  What is his experience with tile?
> 
> Seriously, I'm here reading these boards doing research for a similar project I'm planning this spring.
> 
> If I were in your shoes I would be asking him your questions. Also ask about waterproofing. If he doesn't know, or worse yet, doesn't know what you are talking about you probably don't want to go there. From what I've read this is one area you really want to make sure is done right, and that anyone you hire knows what they are doing.
> 
> I'd rather (mess) something up myself, than have to pay someone else to (mess) it up for me!


I hear you 100%, I'm pretty handy, but know my limits. However, he is a professional Tile installer being layed off or cut back in hours (32 from 40). So he knows what he's doing. however, he and his wife just had a baby 4 days ago and I didn't want to bug him yet with all these questions. I figured if there is board out here like this, I could get a good honest repsonse as I have been without bugging him. So I respect your concern, however, i'm respecing my installers privacy during this great time in his life.

thanks!


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