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IN MY OPINION-- the greenboard is a joke. I would not use it on my own house. If you will have tile use a tile backer board like PermaBase, DuRock, or HardiBacker, this is the only way to go. For untiled areas I think the new fiberglass face drywall would be far superior to greenboard, it is like DensGlas for the indoors I think and has been too long in coming. Mold eats paper and green board still hase paper. This new stuff eliminates the meltable paper face on the board. Can't tell you on how many remodels I have seen melted greenboard in the bath.
Brent Smith, President
American Dreams Construction, LLC
I am not familiar with the range of wet area products available in the US, but here goes...
If you have to use cement sheet, double the quote for the room (labor time), and then add the extra material costs. I have a builder who insists on the stuff, and they have good reason because it is indestructable. It is also a complete pain to work with. Other wet area products may be a welcome alternative.
As for the green board, it probably is unsuitable for truly "wet" areas, if it's anything like the so-called wet-check in Australia. However, the problem with the product has probably been recognized by a few inventive folks, who will be happy to sell whatever waterproofing systems they have available. Any chance of suffering through with the cement sheet where you have to, and using sub-tile waterproofing where you can? Also, do US manufacturers OK the use of waterproofing membranes to standard sheet? If so, you might avoid the extra cost of the green board altogether in places like tiled kitchen splashbacks.
Keep us posted on the new products you find though. A true wet area sheet that doesn't take all day to install would be something I'd like too see down here.
While I switched to Hardibacker and Durock several years ago for most of our marble and granite slab tub and shower surround applications, Sheetrocks Water Resistant Gypsum Panels (Greenboard) are still called out by Cesarstone, Silestone, and several cultured marble manufacturers. We have a tile sub who prefers it for the ease of hanging wire for his motar float. Here in California several communities have not accepted WR Gypboard as a wet wall for years. Recently USG changed its limitations on use of their Water Resistant Sheetrock to state the product was not to be used in tub or shower surround walls. Check their website: http://www.usg.com/navigate.do?reso...psum_Panels.htm
I have heard that the use of greenboard and water resistant mud (also a usg product) might be a mostly California issue. This is causing a fairly good stir out here, as the product was quite regularly used by tile setters.
The first notice I had was a sign posted in the drywall section of a large local material supplier, "Water Resistant Joint Compound no longer available, contact your inspector for substitutes"??? It did not even refer to the gypsum panel issue. I called the Contra Costa County Building Department (usually more causual than the local small cities) and was told to use 45 minute mud "for now". Then they told me the problem wasn't the WRMud, it was the Water Resistant Sheetrock Panels. The manufacturer had pulled his product certifications and there was no need for WRmud as there would be no WR panels. The County will give contractors a little time with this, for now.
Not so in the City of Walnut Creek, CA., the Inspectors office in this Bay Area community of 66,000 said Water Resistant Sheetrock is no longer allowed in wet wall construction, from the moment they got the news. Glad I don't keep stockpiles of materials on hand (the owner of the company thinks I should, but I'm the PM).
Just wondering if this news was out and about, of if I'm the last to know.
On the usg.com site they mention preventing, repairing, cleaning MOLD 3 or 4 times, I wonder if there was a lawsuit over mold???
I use very little MR Bd because I don't even know what it really is good for. I prefer the new mold resistant products or in areas more subject to moisture I use a product like the DensShield. I don't think the MR will be around much longer. I have never seen moisture resistant compound. What company makes it or should I say used to make it? I had it specked in a job once but used a setting compound because that was the best I cound do.
United States Gypsum made Water Resistant Compound made specifically to use with fiber tape on their Greenboard. It was a soft rubbery sort of stuff that never set up completely, couldn't sand it, but of course didn't have to, it was under fiberglass or tile.
They pulled it when they changed their limits of use for Greenboard, while GB is still on the market and can be used for countertop backsplash areas, I suppose, but so can regular drywall.
It's not really a notice they just quietly changed their "limitations on use" on the product page.
You could try www.usg.com then click on products, then in the product selector #1-pick type; #2 pick drywall walls; #3 gypsum panels.
Then scroll down and look for fire code and water resistant panels (or sheetrock) and the product page for Greenboard should come up.
I've copied and pasted the page here:
Fire-rated panels for use in interior areas that require moisture and fire resistance
SHEETROCK® Brand Water-Resistant FIRECODE® C Core Gypsum Panels are manufactured with a 100% recycled green multi-layered face paper treated to resist moisture; a water-resistant gypsum core formulated with superior FIRECODE C fire protection technology; and a 100% recycled moisture-resistant, multi-layered back paper. Perfect for use in areas such as bathrooms, powder rooms, kitchens, and utility rooms with incidental moisture exposure. Not designed for use in high-moisture areas such as tub and shower surrounds.
Features and Benefits
SHEETROCK® Brand Water-Resistant FIRECODE® C Core Gypsum Panels are low-cost, moisture-resistant gypsum panels for areas subject to incidental moisture exposure. (Do not use in tub and shower surrounds; use DUROCK® Brand Cement Board for these applications). Made with moisture-resistant, FIRECODE C gypsum core and 100% recycled, moisture-resistant face and back papers.
Water-resistant face paper, core, and back paper
Offers added fire resistance
SHEETROCK® Brand Water-Resistant FIRECODE® C Core Gypsum Panels are available in 1/2" (12.7 mm) and 5/8" (15.9 mm) thicknesses, 4´ (1,219 mm) wide and available in 8-14´ (2,438-4,267 mm) lengths.
SHEETROCK® Brand panel products are distributed throughout the United States. For specific information about products in your region, contact a United States Gypsum Company sales office or sales representative.
Limitations of Use
1. Do not use in tub or shower surrounds, or other areas subject to constant or excessive moisture. DUROCK® Brand Cement Board or FIBEROCK® Brand AQUA-TOUGH™ Interior Panels are recommended for these applications (see USG system folder SA932).
2. Do not expose to sustained temperatures exceeding 125ºF (52ºC).
3. Avoid excessive or continuous exposure to moisture during delivery, storage, handling and installation. Eliminate sources of moisture immediately.
4. Use adhesive (mastic) materials to apply tile. Do not use mortar-type materials.
5. When applied on ceiling, framing must be 12" o.c. maximum for 1/2" thick panels and 16" o.c. maximum for 5/8" thick panels.
6. When used as a base for tile, fasten panels through to framing (wood or steel).
7. Single-layer application on resilient channels is not recommended where tile is to be applied.
8. Panels to receive tile or other surfacing acting as a vapor retarder should not be installed over a vapor retarder.
9. On wall applications, maintain a gap of 1/4" to 1/2" between the bottom edges or ends of the panels and the floors, or any other horizontal surface where water could accumulate.
Inspect for signs of moisture damage, which may include water stains, paper bond failure, softness in board core or mildew growth. Eliminate sources of moisture immediately and provide adequate ventilation.
Panels may be damaged in a number of different ways. The following information outlines how to repair panels that have edge damage, water damage, paper delamination, improper fit, surface fracture and ceiling panel sag.
Cut back any severely damaged edges to sound board before application.
Use caution when evaluating and repairing water-damaged building systems. Do not investigate or begin repairs unless you are qualified to do so and understand the potential risks involved. In all situations, immediately identify the source of water to prevent reoccurrence of the problem.
Where mold growth is extensive, a qualified independent construction professional should assess your specific situation and help develop and implement a plan that addresses each of the following:
−Eliminating the conditions for mold growth
−Cleaning mold from surface of material(s)
−Removing damaged material that cannot be cleaned
Elimination of conditions
Focus your efforts on removing the conditions that cause mold growth. In the cases of leaking roofs, ceilings, walls, or plumbing problems, repair the source of the water immediately. In a flood situation, follow the American Red Cross and FEMA (Federal Emergency Management Agency) guidelines for the safe return to affected areas. Once you eliminate the conditions for mold growth, the cleaning, repair, or removal begins.
Cleaning or removal
With the help from a construction professional, evaluate your situation to determine if cleaning the water-damaged panels or removing them is the best solution for your situation.
Cleaning water-damaged panels
If cleaning the surface of the materials is your decision, proper scrubbing removes surface mold and mildew. Once conditions for mold growth has been removed, the following procedure is suggested to remove mold growth and staining:
−Use appropriate protective equipment
−Mix detergent and potable water in a clean container
−Use detergent, bleach and potable water for stubborn stains (follow manufacturer´s instructions for use of cleaning supplies; never mix bleach and ammonia); provide adequate ventilation with use of bleach
−Scrub areas that exhibit growth and staining
−Rinse with water make sure you do not soak the gypsum board while cleaning and rinsing
−Allow gypsum board to dry and inspect for visible growth and staining
−Repeat as necessary until affected areas are clean
Proper cleaning addresses the surface of the gypsum board. However, when construction materials get wet, mold and mildew can also be present in the material or structure itself (e.g. wall cavity where they cannot be seen). Eliminating the water source takes care of part of the problem. If you doubt the effectiveness of cleaning, replacement of all water-damaged materials may be your solution. The decision to remove and replace affected materials should be made with care by qualified individuals such as an independent construction professional. USG does not require the removal of SHEETROCK® Brand Gypsum Panels simply because they once were wet. However, if you have conditions for mold and growth and your gypsum board has gotten wet continuously for more than 24 hours or intermittently for many days or weeks, the best assurance against mold growth is elimination of the conditions for growth along with replacement of affected materials. For additional detail to assist your decision, contact the FEMA office near you for more information about the repair of water-damaged structures. Many university extension programs and public health departments can also provide guidance on flood and moisture remediation measures.
All trademarks used herein are property of USG Corporation or one of its subsidiaries.
The Highlights were my own. I had to remove the last few paragraphs on product safety so it would fit. Quite a bit about mold, eh?
While I'm here, Schluter (I don't know if that is the correct spelling) who makes a lot of tile setting products and accessories apparently has a membrane that you can attach over regular drywall that waterproofs it. Then mortar board or thinset and the tiles. So as a drywaller you just hang the rock, the Tile setter of marble guys take care of the wet wall waterproofing. Check with your local Building Department, of course.