As the popularity and sales of glass tile increase, a group of professionals have begun gathering to discuss problems associated with some of the products.

The issues include product-quality questions, the unwillingness of some manufacturers to stand behind their merchandise and a voluntary installation standard.

“We’re afraid that because of bad installers or bad glass, people will shy away from the use of glass in these environments,” said Steve Slutzah, president of Westside Tile & Stone in Los Angeles.

“And some of these people have been doing pools for 15 or 20 years [without] having a problem.”

Slutzah and others attribute the issues, in part, to a recent influx of manufacturers entering the glass-tile market, some with inferior quality products.

For instance, some of the tile aren’t suitable for pool applications but aren’t labeled as such. This tile can be subject to a phenomenon called thermal shock, a cracking in the glass caused by drastic temperature fluctuations. In pool settings, this can occur when the tile bakes in the sun for a long period of time, then has water spilled on it, as on vanishing-edge walls and waterfeatures.

“If you’ve ever taken a glass out of the freezer and then put hot water over it, you’ll see it just shatter,” Slutzah says. “I’ve had experiences with that, where, before the tile was even grouted, it shattered just from the heat.”

Slutzah said his customers are seeing these and similar instances more often than before and questions are arising as to whether the tiles are tested consistently for the problem.

Another issue lies in the way the tile is mounted. In the past, glass tile was manufactured using a paper front rather than mesh backing, so installation took much longer. But more mesh-mounted glass tiles are entering the market as producers try to make the product easier to install.

Problems have been reported with some of the glues bonding the tile to the mesh. Some are water-soluble, Slutzah hears, causing tiles to come off when immersed in a pool or spa. Other times, professionals said, mold will grow behind the mesh due to the lack of an anti-microbial agent — something they hope will be required soon.

“The grid can be a food source for mold to grow underneath the tiles and [in] the grout joints,” said Greg Andrews, owner of Andrews Tile in Agoura Hills, Calif. “If you’re dealing with a clear or translucent glass, you start seeing weird stuff underneath. ...”

Because of this, Andrews has turned down jobs if he doesn’t trust the mesh mounting. But somebody else usually will take on the project.

In response, the tile industry has begun to acknowledge these problems and move toward reducing them. Until recently, no industry standards existed for glass tile, but earlier this year, ANSI A137.2 was released to address issues such as thermal shock.

“When [a product becomes popular], a lot of people want to capitalize on it,” said Stephanie Samulski, project manager for The Tile Council of North America in Anderson, S.C. “All of a sudden people jump on board, and they’re paying attention to selling material and not quality control. So it sort of exacerbates the problem of not having a standard.”

But installers claim that when a problem does occur, some manufacturers are hiding behind another industry standard — this one pertaining to installation. Detail EJ171 of the Tile Council of North America’s handbook states that, on exterior applications or those exposed to moisture, movement joints should be placed every 8 to 10 linear feet, regardless of the type of tile. This allows the material to shift. The standard includes other provisions for interior, dry environments.

“We’ve all faced the manufacturer that says, ‘Well, you didn’t use movement joints, so you own the failure,’” Andrews said. “In some of these cases, they’ll blame the failure on the contractor’s installation method when, in fact, it’s a problem with the product.”

At least in Southern California, some professionals report seeing few, if any, glass-tile projects that actually have the joints, which they call unattractive and perhaps unnecessary. “I understand where it snows and they have freeze/thaw issues that [the joints] may be critical,” said Scott Cohen, president of The Green Scene Design & Construction in Los Angeles. “But the reality is that those aren’t being installed in temperate climates.”

But the TCNA and the National Tile Contractors Association say the standard should be followed despite pressure that sometimes comes from designers and customers to forgo the joints. Glass expands and contracts more than ceramic or porcelain, they said, so movement is inevitable, even if the shell stays completely still. “We’re encouraging people in glass to go on the conservative side,” said Samulski of the TCNA.

The joints actually allow designers to have more control over the final product because they create a controlled location where movement is addressed and consistent, said Johnny Marckx, executive vice president of Oceanside Glasstile in Carlsbad, Calif.

“I think there are creative ways to fulfill the technical specification and still come out with an absolutely beautiful installation,” he added.

Samulski added that the problem can cut both ways, with installers blaming the product for errors made in the field. “If somebody calls somebody out because there’s cracked tile, thermal shock is sort of an easy thing to point to,” she said. “But we don’t necessarily think that all the reports that have alleged that thermal shock is the failure mode necessarily [reflect] really what’s happening there.”

All parties agree that the root cause of failures can be hard to pinpoint, and there may be multiple culprits. With that in mind, it’s important for builders and tile installers to protect themselves as much as possible.

Too often, concerned professionals say, manufacturers fail to provide installation instructions or clarify whether their products are suitable for water environments. This is more common among tiles that are private labeled, purchased online or otherwise of unclear origin. Experts advise that if no instructions and specifications are available, the product should be avoided.

“Because of the nature of glass ... we’re adamant that our members request in writing warranty and product recommendations from the manufacturer,” said Bart Bettiga, executive director of the National Tile Contractors Association in Jackson, Miss. “If a distributor is selling that product, we want that distributor to provide specific recommendations that [the] glass can be used in submerged applications or in different climatic conditions, in wet areas or showers. And then we specifically ask for installation instructions.”

For example, Oceanside will specify the exact products that should be used for setting and sealing its tile. Company officials stand firmly behind the movement joints, but they recommend collaboration between designers, tile setters and even the manufacturer to decide on the number and locations.

Said Marckx: “We believe that you [should] have a team that’s working together toward the same end — not someone who picks a beautiful color mosaic and then an installer who’s left to their own devices to reconcile well-documented best practices for installation vs. an architect who doesn’t like to see that visual break.” After his company has seen the specifics of a project, he said, it sometimes will allow a deviation from the standard.

As for Slutzah’s group, it plans to meet periodically and, in the meantime, help each other resolve specific problems and disputes.