November     2003
Feature
Inspection News and Views from the American Society of Home Inspectors


Tile Problems You Say?

DAVID M. GOBIS

I doubt it! Everyone is quick to blame the tile when it comes loose or cracks or when the tub, shower, or floor leaks, but rarely is the tile itself the real problem. While many issues facing the unsuspecting homeowner can be obvious, flooring is not one of them. Showers are especially difficult to evaluate, and often cost unsuspecting buyers thousands of dollars in repairs and days of inconvenience. As executive director of the industry sponsored Ceramic Tile Education Foundation, it is my job to teach proper installation of ceramic tile and related products. We work in close association with the Tile Council of America (TCA) who represents the majority of American manufacturers. While not our primary focus, we receive thousands of calls and e-mails about ceramic tile and installation problems.

TCA+ANSI+HNDK.gifThe tile industry, unlike other floor covering products, has an American National Standard for the Installation of Ceramic Tile (ANSI A108), an American National Standard for Setting Materials (ANSI A118 ), and an American National Standard for Ceramic Tile Products (ANSI A137.1). Additionally, for the last 41 years, The TCA has published the Tile Council of America Installation Handbook. TCA also has a testing and research lab, which is co-located with the National Brick Research Center on the Clemson University campus in Clemson, SC. The handbook is a guide for anyone who uses, works with or specifies ceramic tile. Photo: These consensus documents serve as a basis for tile installation and setting materials. The current document for tile products, A137.1, is being reballoted and should be available after the first of the year. They are available at www.tileusa.com or 864-646-8453.

Inspecting tile

So what does all this mean to a home inspector? Tile installations have specific guidelines to follow to assure successful installations. These methods are tried and true. In fact, none of the four of us who answer calls about problems with tile can remember an instance where the methods were followed and resulted in a failure. All U.S. manufacturers base their recommendations on either the TCA or American National Standards (ANSI). Some manufacturers offer innovative products that will allow for installations not otherwise deemed as acceptable under industry standards.

This is good, and encouraged, so don’t be quick to fault an installation without complete knowledge of the process and products. We compiled a list of the most frequent problems we hear about from unhappy building owners and others. Below are the top five reasons people called us in 2002. Most of them should be familiar to you, but some may come as a surprise.

#1: loosened tile

The leading contender by far is delaminating or debonding tile. By this we mean tile that has come loose from the substrate (mounting surface). The tile may sound hollow, have a grinding sound, or actually come flying off the floor. This especially occurs on concrete slabs. The cause of the failure may be primarily due to a lack of control joints or soft joints in the tilework and around the perimeter of the area and/or insufficient coverage of adhesive. It is important to the long-term success of a tile installation to provide for movement, which is certain to occur.

The technical reason this failure occurs is that ceramic tile expands and contracts with moisture and temperature at a different rate than a concrete slab or plywood does. Generally speaking, concrete slabs tend to shrink as they cure. This shrinkage can take place for many years. If there is no space to allow a release of the tension created by this “differential expansion,” the tile will come loose. Only the grout will be holding it in place and only for so long. When it goes, it can really cut loose. We had one case where the tile exploded off the floor with such force we found tile shards in the drywall ceiling. In the case of plywood, seasonal movement of not only the sheathing but also of the structure occurs with the change of the seasons. Ceramic tile must be installed with the proper setting materials and provisions made for this expected movement. Also buildings move with seismic shifts, settling, heavy winds, material changes over time, and other factors. It cannot be stressed enough that movement accommodation and/or control joints are required in a tile job of any size, even the smallest bathroom.

#2: Cracked tile and grout

The second most common problem is cracked tile and/or grout. Frequently cracked grout is a precursor to cracked tile, although not always as there are many causes of cracked grout. Tile cracks because of movement of the substrate or cracks in a slab telegraphing through the tile. If a concrete slab cracks and a ceramic tile is adhered to the slab, the tile will crack too. Slabs may crack at any time; however, as years go by the likelihood of cracking decreases. The slab should be cured for at least four weeks or longer depending on cement to water ratios and ambient conditions. For plywood, specific nailing patterns and spacing of sheets is necessary. Improper installation of the subfloor and underlayment are very common problems. Tile industry recommendations are based on continuing joint research with the American Plywood Association as well as with numerous other organizations and manufacturers. Satisfactory performance can be achieved using a plywood substrate when installation guidelines are closely followed for the entire floor system.

Sometimes use of a membrane may be appropriate. Crack suppression techniques include the use of anti-fracture membranes. A slab that has cracked should not be tiled directly, although it can be tiled if preventative measures are taken. Regardless of what is done, the membrane does not eliminate the requirement for control joints described in the section on delimitation.

Deflection.gifAnother major cause of cracked tile is excess deflection in the substrate. Typically this happens on plywood or OSB construction methods, however suspended concrete systems also deflect. Ceramic tile industry specifications call for deflection less than L/360. This means that in any given span the deflection must not exceed 1/360th of the span. The most deflection does not occur over the joists but midway between joists. If a span is 10 feet, for example, the deflection should not exceed 10x12"/360 or 1/3 of an inch. This is usually engineered into the construction by the selection of properly sized and spaced framing members, subfloor, and underlayment; but it can be measured in the field, using a laser level to check deflection under an expected load. Illustration: Deflection not only applies to the floor joist but the entire flooring assembly. The test number for tile floor systems is ASTM C-627 and uses a 300# point load.

One classic call the TCA received was about a large home in the Aspen ski area. This 6,000 square foot home had marble and ceramic tile through most of the floor area. The homeowner called and reported that tile was cracking in all rooms in the house. It had been tiled within the past year. We asked if he had talked to the tile setter to see what he claimed. According to the homeowner, the tile setter said it was normal for tiles to crack. In fact the tile in his own house was cracked. Who would hire a tile setter who had cracked tile in his own house? This problem was traced to inadequate floor thickness, which includes the sub-floor and underlayment thickness in total.

The TCA Handbook for Ceramic Tile Installation, in conjunction with the ANSI standards, spells out the thickness required and the installation techniques specified. Of course manufacturers’ own specifications prevail over generic standards.

#3: Poor Workmanship

Third on our list of oldies but goodies is workmanship. This broad category includes visual results such as grout work, tile spacing, layout, cutting, lippage, and other items that result in a less than desirable job. We find this category tough to deal with because it is subject to the homeowner’s expectations. Sometimes the consumer demands too much, for example very narrow grout joints or no caulk in the control joints. Or designers specify wall-washer lighting that highlights every variation in the tile surface. We literally have heard of consumers who have gotten down on their hands and knees to inspect floors with a magnifying glass.

ANSI standards allow tile to be inspected at a normal floor viewing distance, about 6 feet. To inspect tile at closer range is unfair and uncalled for. Yet there are still many examples of truly unsatisfactory tile work out there. The fix is to remove the tiles in question and replace them correctly. Not a good thing to do, nevertheless sometimes it’s the only way.

#4: Misuse of materials

Next on the list of the fabulous five is the use of improper materials. Materials that are suitable for some uses may not work in others. For example, roofing felt won’t work as a moisture barrier, as an anti-fracture membrane, or as a shower pan liner. Improper placement of certain types of backerboards also causes failure. Bluntly put, there are materials designed for specific purposes. Proper shower pan membranes, high temperature membranes for steam rooms, floor backerboards, vapor barriers, crack suppression membranes, sound reduction materials and other materials must be selected and used properly. When this is done, the manufacturer will stand behind its products; if not, it’s take your own chances.

We can only assume this problem comes from a desire to use cheaper materials and to reduce the types in use. But this will create a potential failure and is false economy indeed.

#5: Moisture

Uncoupling.gifLast on our list is moisture and the attendant problems when it encroaches into wall and floor systems. Incorrectly installed shower pans are a major component of this category. We are asked to define this method by phone fax and email. This is not practical as it takes at least a few days to train an experienced tile setter to properly install a shower pan, the mortar bed and the tile. Some of the causes of failure are puncturing the membrane during installation; failing to slope a shower membrane to drain; installing porous backerboards into wet areas (such as mortar beds and tub lips); failing to caulk joints that move (such as the junction of a tub with the tile work); and other lack of attention to detail that result in gaps in the system. Photo: This example of an uncoupling membrane compensates for structure movement, disipates moisture, and offers crack protection and waterproofing.

It is always a surprise to callers when we tell them that tile work is not waterproof. Tile itself generally is waterproof, but water will get through grout no matter what type and how well it’s installed. The mounting surface must be waterproof in wet areas. This is a key to preventing moisture from entering the wrong areas. And just a drop of water a day can lead to dry rot, mildew, and other undesirable results.

Conclusion

These are the current top five problem areas based on calls we receive. There are obviously many other types of failures that may occur. It is seldom we see a failure as a result of one specific item. Most often it is a combination of issues. Sadly we must report, the overwhelming majority are installation related. As a contractor of many years prior to my current position, I would have readily argued that point until I spent the last five years here answering thousands of calls and e-mails. Product failures of either tile or setting materials are rare, and when they do occur, most often were preventable. When the problems call for answers beyond the scope of a home inspection, there is a resource available. It is an independent but wholly owned subsidiary of the TCA that is designed to fill a need for inspection and consultation. Tile Council of America has a wholly owned subsidiary know as the TCA Team. The TCA Team will perform field inspections, submit a written report, provide advice, testify in court, provide product testing and consultation. In short, the TCA Team has the resources to resolve problems.

Home inspectors who see an unusual amount of tile problems may want to consider the inspection course recently launched by the Ceramic Tile Education Foundation. You can call for more information at 864-222-2131. If you do not have a
current copy of the TCA Handbook or desire a copy of the American National Standards, both can be purchased from the Tile Council of America at 864-646-8453.