# Using Durock for the first time



## NCDrywall (May 29, 2014)

Hello, this is my first post here. I've been lurking for a few months and have read several threads on here already. I'm still fairly new to drywall so I have a lot to learn. I searched for durock and permabase threads and couldn't find much.

I am doing a new custom house job for drywall and the homeowner (a relative) heard about durock and wanted to use it in his showers and tubs. I did some reading on it, including website install materials, but he also has some questions for me that I can't answer. He is a relative, so I want to make sure I do the best job for him. I recommended glue and screw for all of his regular drywall, but he balked at the cost of glue and is worried about the VOC emissions. He is a little neurotic. :wacko: I wouldn't do the job if he wasn't a relative!

It is a single family home on an acre lot so I don't think that a fire rated assembly is required in North Carolina, but I'm not sure. He asked if there should be a 1/2" sheet of green board and then a 1/2" sheet of durock around the showers and tubs. 

He wanted to know if it was ok to screw the durock directly to the wood studs and then tile it, or if anything else is required. 

Then he asked if I needed to add a water barrier between the wood and durock because durock can transfer water. Then he asked if the durock tile membrane is necessary between the durock and the tile. He was worried about possible mold growth sometime in the future. He watches those 20/20 and 60 min type news shows in addition to the Doctors. I think all the  that they put on these shows just makes him more :wacko: .

I said I'd have to get back to him about it.

Anyway, what would be the best install method for using durock? Is there anything else I should be aware of? 

I know I need to use the special screws and mesh tape with mortar. Although, I should probably pass the taping and mortar off to the tile contractor, whomever it might be.


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## nodnarb (Apr 25, 2014)

Just screw it as normal but be more careful as it is EASY to go all the way through. Clutch em in to hold well. You can get serrated utility blades that can cut it pretty well although it takes a couple passes because of the threads in rock. Circular saw and diamond blade lays waste to it but is super dusty and nasty. Definitely wear a mask, its a very distinct and awful smell..

I should say outright I do commercial on steel framing 95%+ of the time, I am unsure of any special preventatives for wood framing.


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## MrWillys (Mar 10, 2014)

A minimum of a grade D felt paper should be installed starting at the bottom and lapping each row 2" as you go up. Tell him to ask the tile contractor about barrier between cement board and tile. Your job is done with felt paper and board. Felt should lap over fiberglass pan lip if one is used.


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## NCDrywall (May 29, 2014)

If grade D felt paper is the minimum, what is the maximum? Grade D, 60 min? I know he used #30 felt (or maybe asphalt kraft paper) for the roof (with 50 yr shingles  ) and probably has some left over. He has cast iron for the tubs, but the shower pans are fiberglass. I know he also has some vinyl wrap rolls left over from the window install, would that work also? He likes function over form and he's putting in high quality building materials everywhere. 

Thanks for the heads up on the cutting, I'll just use my serrated utility blades for it.


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## Corey The Taper (Mar 18, 2014)

Around here they just screw the tubs to the studs with nothing else and for stand up showers or anything that calls for durarock they usually just screw it to the studs also with some kind of screw. But im no hanger


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## imaginethat (Apr 16, 2014)

Just hang the durock to the studs ne felt. Make sure you use the screws made for it. Mesh tape the seams with the mesh for mortar. Mortar all seams and corners. Then apply 2 coats od red guard.


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## nodnarb (Apr 25, 2014)

imaginethat said:


> Just hang the durock to the studs ne felt. Make sure you use the screws made for it. Mesh tape the seams with the mesh for mortar. Mortar all seams and corners. Then apply 2 coats od red guard.


What screws "made for it"? Ive hung TONS of perma base with plane jane sheetrock screws. If you clutch them in they hold as good as anything. Its silly to buy special screws for one or two pieces on a shack when people dont use these special screws for 20-30 pieces on a commercial job. I HAVE used coreboard screws on an especially brittle piece going into wood though. Are these special screws coreboards by chance? 

The tapers here hit joints with hot mud and mesh tape before tile goes up, only time I've seen mortar used is if the wall wasnt prepped for tile guys before hand. Honestly I think durabond is tougher than tile grout anyday. Just my .02


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## imaginethat (Apr 16, 2014)

They are called rock-on or backer-on. Home depot carries them. Sheet rock screws will rust. Just because other people doesn't use them doesn't mean you should do subpar work to. The mortar ties everything together making a better surface for tiling. Then you put 2 coats of red guard on. It rolls on like paint but dries to make one continually rubber water proof membrane.


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## MrWillys (Mar 10, 2014)

Here it is from USG.

 D​​​​urock cement board is vapor permeable and does not deteriorate in the presence of water. For interior​
applications, if a vapor retarder or waterproof construction is specified, a separate barrier must be applied​over or behind the Durock cement board.

http://www.usg.com/content/dam/USG_...durock-cement-board-system-guide-en-SA932.pdf

a shower must be waterproof, so whether you put the vapor retarder behind, or on top is up to you.


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## nodnarb (Apr 25, 2014)

imaginethat said:


> They are called rock-on or backer-on. Home depot carries them. Sheet rock screws will rust. Just because other people doesn't use them doesn't mean you should do subpar work to. The mortar ties everything together making a better surface for tiling. Then you put 2 coats of red guard on. It rolls on like paint but dries to make one continually rubber water proof membrane.


My work is insured. And I do high end work, id hardly call it subpar and I bet you wouldnt should you see it . Certainly not to my face !! Keep in mind im not doing showers 99.9% of the time im doing restruants and bathrooms and whatnot where water doesnt directly go on it 24/7 and there hasnt been an issue with ANY of it . 
I havent seen a detail one that calls for any "special screws" . No need to be a  and make assumptions.

If my screws rust through someone ELSE didnt do their job right! Be it plumber or tile guy.


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## imaginethat (Apr 16, 2014)

Nodnarb, not trying to insult you. For your work that you do your method works and I would probably do it the same. He was asking how to do a shower. So I told him the best way to do a extremely wet area. I hate to see people have to tear out a shower a few years down the road. In a non wet area regular screws work fine. I'm sure you do good work but what you described just isn't the best for showers.


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## MrWillys (Mar 10, 2014)

imaginethat said:


> Nodnarb, not trying to insult you. For your work that you do your method works and I would probably do it the same. He was asking how to do a shower. So I told him the best way to do a extremely wet area. I hate to see people have to tear out a shower a few years down the road. In a non wet area regular screws work fine. I'm sure you do good work but what you described just isn't the best for showers.


And the correct fasteners are listed in the USG SA .pdf I posted.


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## NCDrywall (May 29, 2014)

Thanks for all the tips and pointing me to the red guard product. It looks like I will use that.


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## NCDrywall (May 29, 2014)

My relative had some issues with the local USG distributor not wanting to get regular drywall instead of the lite drywall. So he had to special order from an NG distributor. Now he will be using Permabase. It looks very similar to the Durock. Can someone confirm that it installs the same?


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