Tile can be easily installed when the proper substrate preparation is provided and jobsite conditions are addressed. However, when a tile job is outside and the weather raises concerns, the problems, if not addressed, can be catastrophic.

This was the case for tile being installed on the exterior of a building using Tile Council of America (TCNA) method W202E, Exterior Walls with Ceramic Tile on Masonry or Concrete. The substrate was properly prepared and ready for tile, but unfortunately, the upcoming weather was not. Similar to the weather experienced throughout much of the United States this summer, the consistent 95°F days with a heat index of 105°F  were not suitable for installing tile. In addition to the hot temperatures, the site experienced consistent winds of 30 to 40 mph.

The installation began in the shade of the building early in the morning while the temperatures were in the mid-seventies, yielding a satisfactory environment. However, regrettably, when the shade of the building disappeared, the afternoon sun shone directly on the area where the tilework was progressing. The combination of the hot sun shining on the concrete substrate and the winds blowing across the thin set caused it to skin over, which should have been a clue to the installers that these conditions were not ideal; however, the work continued until the job was completed.

The completed tile installation appeared to be satisfactory for a while. Shortly after the building was finished and occupied, the hot sun shone on the chestnut brown porcelain tile, causing it to expand and shear off the concrete wall. To the casual observer, the tile still looked to be okay. However, after several days of consistently high temperatures and continued heat expansion, the tile came loose and fell to the ground, some of which was twenty-five feet high. Fortunately, the yet-to-be-completed landscaped area immediately in front and below the wall allowed the tile to fall harmlessly to the ground. Nobody was hurt, but the tile installation was a total loss.

This failure included numerous errors. The thin set, per the manufacturer, should have been used at between 40°F and 90°F, the environment was prohibitive, and the job should have been stopped. If work was to be continued, the area should have been tented to shield  it from the sun and wind or installed at night when the temperature was within the manufacturer's recommended range. Image # 1 shows that the trowel used did not provide enough mortar to meet the TCNA required 95% mortar coverage, and the skinned-over mortar did not transfer to the back of the tile, as seen in the “clean” back of the tile in image #2. One additional issue that is essential for exterior tile installations is the inclusion of movement joints per TCNA EJ 171. This job lacked the capacity to manage the experienced expansion.