Greenboard Shower info

[flatfloor]

This from Newsday our local paper. I posted here first for comments, maybe it should go in the Liberry? I'm also going to invite Gary to visit.

It's a Scary Shower Scene
Gary Dymski

November 21, 2002

My daughter Melissa emerged from our steam-filled main bathroom. "Dad, there's something not right in the shower," she said.

What usually follows such a pronouncement is a complaint about the lack of hot water or the shrinking household supply of floral-scented, herbal-injected, honey-colored, overpriced shampoo.

This time, however, the complaint was worth hearing - our shower wall had collapsed. My daughter was convinced our house, built in 1997, was crumbling before her very eyes. "I just put my hand on the wall while getting out of the shower, and the wall just gave way," she explained, looking at the large indentation behind the ceramic tile. "What's the deal?"

The deal is that the shower wall in our main bathroom must be completely replaced. When the tile in our bathrooms was installed, it was installed against greenboard. Eventually, I will have to rebuild three shower walls, and if I go with tile again, you can bet I won't be using greenboard, a water-resistant gypsum wallboard, as a backer board.

Several upcoming columns will deal with this project, from the tearing out of the existing moldy, mildewy shower wall to complete installation of a new wall, either of tile or a one-piece acrylic.

But before we get to the project, my question is: Why are builders and contractors allowed to use greenboard or wallboard as a backer for ceramic tile? My experience is that wallboard fails repeatedly as a substrate for ceramic tile in wet areas. So why aren't newer materials, like water-friendly cement backer boards, required by local building departments for such installations?

As a resident of Brookhaven, I posed this question to Tom Moore, a town building inspector. According to Moore, town building regulations often call for the absolute minimum standards. And in the case of ceramic tile on water-bearing walls, regular wallboard will do in Brook- haven. After a series of questions about my builder and the age of the home, Moore suggested my collapsed wall was the result of installation failure rather than product failure. "If a tile job is done correctly on wallboard, it can last 50 years and never come down," he said.

Robert Wessel, assistant executive director of the Gypsum Association in Washington, D.C., agrees. "Water-resistant gypsum backer board is specifically designed [by their manufacturers] to be used as a substrate for plastic or ceramic tile," Wessel says.

Why did the wall fail then, not after 50 years but after about five? Wessel blames installation and maintenance. "Under the newest installation recommendations," Wessel said, "wallboard is supposed to get a skimcoat of ceramic tile adhesive before the tile is installed." Once the adhesive dries to create a more water-resistant substrate, then the tile can be installed. Wessel said many contractors skip this newer recommendation. "Not knowing how they built your shower wall, the contractor could have missed this step," he says. "Also, the grout and sealants in this wall must be properly maintained. Once water gets between the grout and behind the sealant, the substrate can fail."

That's precisely the problem with using gypsum boards, says Justin Woelfel, director of training and education for the National Tile Contractors Association in Jackson, Miss. "With gypsum board, there's no room for error," Woelfel says. If even a small amount of water gets behind the tile, the substrate can fail.

Woelfel says that members of the National Tile Contractors Association are specifically instructed not to use gypsum board as a backer for tile in extremely wet areas. "The reason builders use wallboard is that it is cheaper and easier to install," Woelfel says. "Some builders don't want to pay the price to do it right the first time." (Cement backer board costs more, is heavier and often more labor-intensive because it should be cut with a reciprocating saw. Gypsum is lighter and can be scored with a utility knife.)

Woelfel said there are more than a dozen newer substrates that can be used, many of which meet the American National Standards Institute guidelines for ceramic tile installation, which his association follows. Many of these newer backer boards are cement-based panels with names like Wonderboard and Durock.

Cement backer boards mimic the traditional way of installing ceramic tile, which was to create a wall or subfloor of concrete held together by metal lathe (called a "mud job" in the trade). These backer boards are cement panes wrapped in fiberglass mesh, and when tile is applied to them using thinset mortar the result is almost as good as a mud job.

In fact, the National Gypsum Co., a major wallboard manufacturer, has recognized the success of cement boards. It now makes its own cement board, PermaBase, to be used as a substrate on wet walls. The company also says greenboard should not be used on walls that come into continual contact with water.

So, if the new shower walls in the Dymski household are lined with ceramic tile, it's a lock that cement backer board will be the substrate.

"I think you're on the right track," Woelfel said.

First, there's a little matter of tearing down the rest of those existing walls.

Although he cannot always respond personally, Gary Dymski welcomes letters. Write to him at Newsday Home Work, 235 Pinelawn Rd., Melville, NY 11747-4250 or e-mail gary.dymski@newsday.com. Include your community of residence.
Copyright © 2002, Newsday, Inc.

[Dave Gobis]

It is them greenboard showers again. I can not disagree entirely with Mr. Wessel, but, I have never seen a shower installed in my lifetime that followed their (Gypsum Associations) recommendations. Here is a copy of what I forwarded to him.

Gary,
Greenboard has not been a recommended substrate for ceramic tile in wet areas for a number of years. The issue is a little more complex than Mr. Wessels comments and space may have allowed you. There are standards for tile installation in the United States. They are referenced by virtually every major American manufacturer of tile and setting material in their literature.

The Tile Council of America, Inc. (TCA) publishes the Handbook for Ceramic Tile Installation, The Handbook is a guide for anyone who uses, works with or specifies ceramic tile. It clarifies and standardizes installation specifications for ceramic tile in the United States. It is a quick-reference details that outlines most installation methods and conditions such as exterior and interior floors, exterior and interior walls, ceilings and soffits, bathtubs walls, counter tops, renovations, shower receptors, steam rooms, swimming pools, fire-related and sound-related walls, etc. The book provides a guide on recommended uses, limitations, requirements, materials, preparation by other trades, movement joints, installation specifications and references ANSI and ASTM standards. The information presented in the Handbook for Ceramic Tile Installation represents a consensus of more than 23 national and regional organizations.

The United States has used the ANSI (American National Standards Institute) A108 as its standard for installation many years. This document sets the definitions and standards for proper installation of ceramic tile. The A108 was last published in 1999. One of ANSI's requirements is that standards are revisited and re-approved every five years. The Tile Council is approved and recognized as the secretariat for the ANSI standards for the ceramic tile industry. All of the ANSI and ASTM (American Society for Testing Materials) standards, definitions, and methods are subject to open review called transparency. This prevents any one group or industry segment from dominating the process and thus promulgating inferior standards. These standards are designed to act as a platform for establishing commonality between the producer, specifiers, middlemen, installers, and end users. Organizations are invited to participate in the standards generating process. Those that have an identifiable interest are invited to send voting members to the committee meetings. The existing committee then approves new applications. It is not an individual serving on the committee but rather an appointee of the organization he or she represents. The fact that standards are being considered and balloted is published in ANSI notifications such that all potentially interested parties are notified. No legitimate interest is excluded and anyone may submit comments and suggestions to the committees. The make up of the committee is audited by ANSI to confirm that no segment dominates the process. Guests may be invited to sit in on meetings to state any particular viewpoint. Once the committee completes its deliberations a draft of the standard is prepared and submitted to ANSI for balloting. To be considered for a standard all one must do is submit their proposed product, installation specifications, and supporting ASTM recognized test data.

[John Bridge]

Davey,

Why didn't you just tell him sheetrock showers ain't no good?

[John Bridge]

Jim,

Get the guy over here. We'll be famous all over Lon Gisland!

[flatfloor]

More than LI, that paper is owned by the LA Times also includes Chicago Times(?) and I don't know what else.

Gary writes a very good syndicated homeowners column. he subsequently sent me this email:

Thanks so much for your reply; I'm expecting some nasty comments from
wallboard manufacturers who still insist that greenboard can be used
successfully as a backer board in wet areas like shower and tub surrounds.
I have NEVER seen it last more than 10 years.



[Edited by flatfloor on 11-21-2002 at 09:35 PM]

[John Bridge]

I think you'd better file this in the Liberry for the time being. Maybe we'll get time one of these days to get all that stuff into usable form.


Or maybe we'll put it on a web page and link it to the real site.

[Mike2]

Greenboard No Longer an Approved Substrate for Tub and Shower Areas

The International Residential Code (IRC) has determined that effective January, 2006, paper-faced greenboard will no longer meet its standards as an approved tile backer substrate for wall tile in wet areas such as tub and shower areas.

IRC, Chapter 7 - Wall Covering

R702.3.8 Water-resistant gypsum backing board. Gypsum board used as the base or backer for adhesive application of ceramic tile or other required nonabsorbent finish material shall conform to ASTM C 630 or C 1178. Use of water-resistant gypsum backing board shall be permitted on ceilings where framing spacing does not exceed 12 inches (305 mm) on center for 1/2-inch-thick (13 mm) or 16 inches (406 mm) for 5/8-inch-thick (16 mm) gypsum board.

Water-resistant gypsum board shall not be installed over a vapor retarder in a shower or tub compartment. Cut or exposed edges, including those at wall intersections, shall be sealed as recommended by the manufacturer.

R702.3.8.1 Limitations. Water resistant gypsum backing board shall not be used where there will be direct exposure to water, or in areas subject to continuous high humidity.

The new requirements are:

R702.4.2 Cement, fiber-cement and glass mat gypsum backers. Cement, fiber-cement or glass mat gypsum backers in compliance with ASTM C 1288, C 1325 or C 1178 and installed in accordance with manufacturers’ recommendations shall be used as backers for wall tile in tub and shower areas and wall panels in shower areas.