Consequences Of Moisture Problems -- Due to poor dam construction, moisture infiltrated structural components of this shower enclosure. A complete tear-out and replacement installation remedied the problem.

From dealers and specifiers to installers and inspectors, almost everyone involved with the tile and stone industry knows that the Tile Council of America's (TCA) Handbook is the preeminent reference guide for installation methods and standards.

The handbook -- which is updated, revised and published annually -- should be given a permanent place in everyone's files. It is readily available from a number of sources, including Anderson, S.C.-based TCA itself, the Ceramic Tile Institute of America (CTIOA) in Los Angeles and various manufacturers.

The handbook, now in its 40th edition, clarifies and standardizes ceramic tile installation specifications. The CD-ROM version of the manual offers quick reference CAD details, and a complete library of more than 70 U.S. manufacturer catalogs featuring ceramic tile, raw materials, equipment, and installation products.

Along with ANSI A-108, the TCA Handbook goes a long way in helping to prevent job-related problems. In this column, I'll cover what I consider to be among the more noteworthy revisions to the handbook.

Don't take a bath on a failed installation

One TCA installation detail that draws constant criticism is Detail B413-02, which covers bathtub walls where water-resistant gypsum board is used and the ceramic tile is bonded with an organic adhesive (hopefully type I) or latex-modified Portland cement mortar.

If you review this detail, you'll notice the word "Caution" in bold type. This admonition is a warning about substrate limitations. In other words, the success of an installation is dependent upon the durability and dimensional stability of the substrate (i.e.: plain or water resistant (WR) gypsum board.)

Detail B413-02 goes on to say that some materials in wet areas are subject to deterioration from moisture penetration. Generally speaking, moisture penetration or damage from the ceramic-clad side is minimal provided a skim coat of mastic is spread first (as many manufacturers recommend).

Unfortunately, many of the problems that occur are the result of pipe leaks. In such instances, disintegration begins on the reverse side of the tile where the installation has no water-resistance capability.

I dislike contributing to the current litigation Super Bowl relating to mold problems. However, it is in these situations where mold can occur, particularly as the moisture being absorbed into the substrate also infiltrates the studs. Alternative installation systems possibly could relieve the trade of becoming mired in costly litigation.

Another factor contributing to bathtub wall problems is the common practice of using hard grout (such as Portland cement grout) at the joint between the wall tile and tub. These joints will crack eventually -- sometimes due to improper mixture of the grout and sometimes because of floor or building movement or settling, or studs shrinking and twisting.

Again, this can be a window for moisture intrusion and the problems associated with it. TCA details and ANSI A-108 show that flexible sealant should be used at these wall-tub joints. Personally, I would be more concerned about a using a sealant to maintain a watertight joint then I would about having a color match.

Keeping the shower dry

While we are still discussing the bath/shower room, I must point out that there are many problems associated with drains -- primarily problems at the weep hole configuration. Many contractors fail to keep these weep holes clear. Some allow mortar mud to block these holes.

Under the heading "Preparation By Tile Trade," the TCA Handbook advises that the drain should be surrounded with broken pieces of tile or crushed stone to prevent mortar from blocking weep holes. That doesn't sound difficult or complicated to me.

Another problem encountered is associated with the entry to a handicapped shower enclosure. Other flooring materials are frequently affected by moisture that escapes from the entry. The minimum distance between the opening and drain should be 4 feet.

In addition, because no dam exists, protection for flooring immediately outside the handicapped shower should include not only a membrane but also the extension of the floor tile into the floor area.

Other than the details I've discussed here, the 2002 TCA Handbook is basically the same as the 2001 edition. Apparently, TCA details are performing satisfactorily. Be sure to get a copy of this handbook and increase the odds that your installations will perform satisfactorily, as well.


Tile Council of America: (864) 646-8453;

Ceramic Tile Institute of America: (310) 574-7800;