Replies

1. 
   Taylor | Jun 12, 2005 01:26am | #1

   What I've heard: GB was developed for tiling over. Now several decades later, it has finally been outlawed for tiling (use CBU instead). It basically doesn't have a reason to exist any more.

   Don't use GB on the ceiling (unless you're framing 12"oc).

   Don't use GB with a vapor barrier behind it.

   If it gets wet, it turns to mush, same as SR.

   It is not as stiff as SR.

   Other than that, it's great.

2. 
   NickNukeEm | Jun 12, 2005 02:32am | #2

   Ahhh, what he said.

   The only real problem with greenboard (other than what was pointed out by Taylor) is that it gives those who don't know better a false sense of security about using it where it shouldn't be used, which, arguably, could be just about everywhere.

    

    

   I never met a tool I didn't like!
3. 
   cic317 | Jun 12, 2005 03:32am | #3

   Here in NY it's a standard install in bathrooms for the last 20 years w/ no problems. Just don't use it in wet areas of the tub or shower, stick w/ cement board.

4. 
   dIrishInMe | Jun 12, 2005 03:35am | #4

   Are you talking about tiled areas?  If a contractor wants to set bathroom tile on regular sheetrock, get another contractor.  Like Nick said though, even greenboard isn't that great - it's more under the "water resistant" category.  For tile, backer board is the way to go.  Some guys around here are setting wall tile on Denseshield (sp?) as it is more like working with sheetrock with than Durock or similar cement backer board.    Really though, for a wet tile location like a shower, cement backer is the best way to go.

   On the other hand, if it's a 1/2 bath, (no bath/shower) regular sheetrock is OK porvided you don't have little boys who like to pee on the walls ;-)

   Matt

   
   

   ---

   Edited 6/11/2005 8:40 pm ET by DIRISHINME

1. 
   JoeyB | Jun 12, 2005 06:06am | #5

   Nope, not talking about tiled areas, just the rest of the bath, ceiling and walls.Coming to you from beautiful Richmond, Va.

1. 
   quicksilver | Jun 12, 2005 06:54am | #6

   My understanding is greenboard is more water resistant. In my experience I have never seen is behave differently than regular sheetrock, but I've only used it in bathrooms, so there might be some merit to the comment above. Today there is much hubub about mold. FHB ran an article a couple of months ago, saying mold needs water, air and organic material such as the paper face of DW or GB to grow. So on our next job we are going to use cellulose covered drywall eliminating one of the necessary ingredients for mould. These may be unnecessary or overkill, but it can be used as a selling point to the clients here in the city. Allow me to edit so I can concur with your last statement: I'm not talking about tiled areas either.

   Edited 6/11/2005 11:57 pm ET by quicksilver

1. 
   BillBrennen | Jun 12, 2005 07:24am | #7

   You wrote: " So on our next job we are going to use cellulose covered drywall eliminating one of the necessary ingredients for mould."Huh? Tell me more. Paper is mostly cellulose. If not joking, you refer to something I've never heard of. Mold will eat cellulose.Signed, Cornfused

1. 
   quicksilver | Jun 12, 2005 01:43pm | #8

   http://www.usg.com:80/navigate.do?resource=/USG_Marketing_Content/usg.com/web_files/products/prod_details/FIBEROCK_Brand_Aqua-Tough_Fiber-Reinforced_Gypsum_Interior_Panels.htm Try this link Sorry my bad, memory banks were sparking a little last night. Cornfused is a word I hear often - one of my bosses favorites. I was at a trade show last summer where I saw the product first. It has like a shiny glaze over it hence how I got cornfused. Here in DC the real estate market is really hot. and our clients are well to do professionals. I don't really know how real this mold scare is, I guess with well executed construction techniques -its really no scare at all. But it is something in the cients mind. And there seems to be some lawsuits happening. My cousin, a major player in a much larger company than ours, told me once "mold is the 21st century's asbestos" Maybe that's lawsuit wise. I don't know. But a comfortable client is more apt to buy. Thanks for keeping me on my toes.

   Edited 6/12/2005 8:31 am ET by quicksilver

2. 
   rez | Jun 12, 2005 05:35pm | #9

   I'm curious what system you are using to provide such a wide page on your last response?

   I even opened the page into a full window and still can't get the last couple words of each line to show.

   be quizzed

   A person with no sense of humor about themselves is fullashid 

3. 
   quicksilver | Jun 12, 2005 05:47pm | #10

   I have a mac. I'm using OSX. I think it (the URL) works as a link. If not try pasteing it. Go to the usg homepage. It's not hard to find

   Edited 6/12/2005 10:49 am ET by quicksilver

4. 
   BillHartmann | Jun 12, 2005 09:16pm | #15

   Prsopero, like many BB and websites automattically wraps the screen at the next available line break (SPACE) to fit the users screen.However, when you post something without a space, like a URL, there is no place to break the line thus you get long scrolling windows.If you know HTML you can post a "title" to the link and the link it'self is not shown. Some BB handle that automatically and convert it to something like http://www.xyz.com....thispage.htmlWhen I find a long URL like that I http://www.tinyurl.com to make a short one.

5. 
   BillBrennen | Jun 13, 2005 07:30am | #20

   QS,Thanks for the link. Reading it through, it appears that this new "Fiberock" is seeking to be the upgrade from regular drywall. Reading the disclaimers makes it sound like "son of greenboard." It handles splash, but not soaking. Has to be replaced after a flood, etc. Not enough about what it is made of, but the lack of a facing paper is intriguing. It looks like a potentially superior alternative to regular drywall, but can't be sure without trying it. Did the rep give out samples at the show?Cornfused no longer

6. 
   quicksilver | Jun 13, 2005 12:56pm | #21

   He had small pieces at the table.. I will do more research myself, I don't consider this an alternative to cement tile backer. Man there sure is a lot to learn about new products today. I saw some carpenters that II sort of know working across the street from me the other day. There were replacing some, a lot, of rotted trim with a product called miratech, an MDF like product that I guess is made with a special resin. Anyway on terms of friendly criticism with them so I asked if they read the instructions. Of course not. I picked up the paper of the ground. field prime all end cuts - everything you would expect, but I thought "there is no way this stuff is going to hold up". I got home and went to their website and they make some impressive claims. My point is that many new products are much more dependant on the required installation techniques than the traditional ones most of us are used to, and to many of us aren't following directions. I guess that's a good thing about this website: 'it' keep ya on yer toes' Ryan

7. 
   BillHartmann | Jun 13, 2005 02:57pm | #22

   That is the type of DW that Andy Engel suggested using in the basement finishing story a couple of months ago.

8. 
   Taylor | Jun 15, 2005 03:12pm | #25

   That Fiberock might also be good as backing for Kerdi. Schluter recommends plain old DW but Kerdi has a perm rating of about 14, so there will be air vapor getting back there.

2. 
   Piffin | Jun 12, 2005 11:36pm | #17

   It is not more water resistant. It is more moisture resistant.We use it regularly in bathrooms and kitchens but not behind wet areas 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

1. 
   Fonzie | Jun 14, 2005 04:50am | #24

   Piffin, Am I remembering wrong or did the insides of greenboard used to be "clay like", dark in color - whereas what comes now looks the same except for the paper & ugly green.

5. 
   Zano | Jun 12, 2005 06:42pm | #11

   Greenboard is garbage..should not be used as it acts as sponge and it takes a long time for it to dry out.  Use the Dens-Shield ..it has a layer of plastic for tile backers or Hardi board.

1. 
   JoeyB | Jun 12, 2005 06:54pm | #12

   I probably was not clear in my earlier post, I am NOT talking about tiled areas. Cement board is used behind tile. I am asking if greenboard is neccesary for the ceiling and walls in the REST of the bathroom.

   Coming to you from beautiful Richmond, Va.

   Edited 6/12/2005 12:03 pm ET by Joey B

1. 
   Zano | Jun 13, 2005 05:18am | #18

   I am asking if greenboard is neccesary for the ceiling and walls in the REST of the bathroom.

   No!  Just use regular drywall and use a good primer/sealer and a semi gloss paint.

1. 
   Dinosaur | Jun 13, 2005 07:12am | #19

   We use green gyprock in baths, kitchens, and laundry rooms in the application you describe. I used to use it behind tile, but I have converted to ½" CBU exclusively now. No troubles so far from the past, but I'm not looking for any new ones, either....

   One thing about greenboard is that it will take at least 1 coat of primer and three colour coats before the dratted green colour stops showing through.

   As it's used in damp areas, we use paint formulated specifically for kitchens and baths.

   Dinosaur

   A day may come when the courage of men fails,when we forsake our friends and break all bonds of fellowship...

   But it is not this day.

6. 
   doodabug | Jun 12, 2005 07:48pm | #13

   It may depend on code in your area. I only use it behind vanity and toilet.

7. 
   DanH | Jun 12, 2005 08:04pm | #14

   My experience is that greenboard is maybe twice as water resistant as regular drywall. That is to say it can take three or four moderate soakings before going bad, while drywall will go bad in one or two.

   This makes it worthwhile for drywalled areas that may be occasionally splashed (adjacent to shower/tub, eg) and for areas where a plumbing malfunction may result in some water squirting about (behind the toilet, etc). Also, it may be worthwhile in situations such as an entryway where rain seems to blow in on occasion.

   However, the stuff is in no way waterproof, and should not be used for surfaces that will be regularly splashed or soaked.

1. 
   BillHartmann | Jun 12, 2005 09:24pm | #16

   Apparently it is (was) being used behind wet walls in CA.http://forums.jlconline.com/forums/showthread.php?t=27000

8. 
   jonblakemore | Jun 14, 2005 01:21am | #23

   Joey,

   We use MR drywall in any potentially wet area. Bathrooms, behind countertops in kitchens, etc. It may or may not hold up better than regulare DW but the extra cost is minimal so it's cheap insurance.

   Of course tile always goes on top of either concrete or CBU.

    

   Jon Blakemore

   RappahannockINC.com Fredericksburg, VA

9. 
   JTC1 | Jun 15, 2005 09:52pm | #26

   Joey,

   I'm really late getting into this fray.

   Remodeler, mostly kitchen and baths.  Bathrooms I use 1/2" green board on all walls except areas to be tiled, they get 1/2" cement board.

   Ceilings get 5/8" greenboard - the 1/2" will ultimately sag even on 16" centers.  %/8" is typically not available at the big boxes, but all of the drywall suply houses have it here.

   If the house has 24" roof truss centers then add your own strapping on 12" or 16", attach greenboard to that.

   Screw everything with corrosion resistant screws, vinyl corner beads work well -- no rust stains.  The perforated edge stuff attaches nicely with SS staples to hold until mudded.

   Jim

   Never underestimate the value of a sharp pencil or good light.

    

   P.S.: I tear out a lot of bathrooms with standard drywall as the original install, sometimes good, sometimes not.  Always not when behind a tile tub surround.  Usually OK when on walls, mixed on ceiling, standard is usually bad on ceilings with marginal or no insulation (lots of condensation in winter).