One of the most exciting developments in the 2021 edition of the International Building Code (IBC) are the new opportunities to use large-format adhered porcelain tile and ultra-large-format tile panels on building exteriors. The new code language represents the first major update for porcelain tile since its introduction to the IBC in 2009.
The International Masonry Institute (IMI) and the Tile Council of North America (TCNA), with the cooperation of tile and setting material manufacturers, jointly proposed these new criteria for exterior tile to the International Code Council (ICC), who unanimously approved the proposal and implemented the language into the 2021 IBC.
The new requirements respond to the increased availability of larger, thinner porcelain tiles, improved technologies in bonding mortar, and the tile industry’s focus on qualified labor. The updated section from the 2021 IBC reads as follows in its entirety:
1404.10.2 Exterior adhered masonry veneers – porcelain tile. Adhered units weighing more than 3.5 pounds per square foot (0.7 kN/m²) shall not exceed 48 inches (1219 mm) in any face dimension nor more than 9 square feet (0.8 m²) in total face area and shall not weigh more than 6 pounds per square foot (0.29 kN/m²). Adhered units weighing less than or equal to 3.5 pounds per square foot (0.17 kN/m²) shall not exceed 72 inches (1829 mm) in any face dimension nor more than 17.5 square feet (1.6 m²) in total face area. Porcelain tile shall be adhered to an approved backing system.
Code Requirements from 2009 Through 2018
In 2009, porcelain tiles meeting ANSI A137.1 American National Standard Specifications for Ceramic Tile were typically manufactured to a thickness of ⁹/₃₂ to ⁷/₁₆ in. (7 to 11 mm), and were adhered with mortar manufactured in compliance with ANSI A118.4 American National Standard Specifications for Modified Dry-Set Cement Mortar. Due to safety concerns and recommendations of the tile industry at that time, the IBC limited the size of these relatively thick and heavy tiles to a maximum of 24 inches (610 mm) in any dimension and a maximum area of 3 ft² (0.28 m²) for any one tile. Moreover, the IBC imposed the restriction that any one tile shall not weigh more than 9 pounds per square foot (0.43 kN/m²). By today’s standards, these requirements seem overly restrictive, but they served the tile industry well in the last decade.
What Factors Sparked the Code Changes?
It is now safer and more efficient than ever to use larger, adhered porcelain tile. This is a result of major industry improvements over the last decade like larger and thinner tiles, stronger mortars and increased focus on installer training and certification programs.
Larger, Thinner Tiles
Porcelain tile manufacturers worldwide now have the technology to produce tiles that are significantly thinner and larger than tile manufactured in previous decades. Porcelain tile manufactured to ANSI A137.3 American National Standard Specifications for Gauged Porcelain Tiles and Gauged Porcelain Tile Panels/Slabs are commonly ¹/₈ to ⁷/₃₂ inch (3.5 to 5 mm) in thickness. Gauged porcelain tile panels (GPTP) also frequently have facial dimensions nearly as large as 6 x 12 feet (1,800 x 3,600 mm in actual size). The thinner profile of these tiles results in units that remain relatively lightweight despite their ultra-large format.
Just as tile manufacturers were developing technology that would test the limits of tile size and thickness, setting material manufacturers were improving their products to provide more tenacious bond strength. ANSI A118.15 American National Specifications for Improved Modified Dry-Set Cement Mortars was approved as a new standard in 2014, establishing more rigid criteria for resistance to shear forces. For example, the required 28-day shear strength of mortar meeting ANSI A118.15, the standard recommended by most GPTP panel manufacturers, is double the requirement for mortars meeting ANSI A118.4, at 400 psi (2.76 MPa) and 200 psi (1.38 MPa), respectively.
Industry Focus on Qualified Labor
Even with these tremendous improvements in materials, the tile setters, finishers and contractors installing them must be qualified. Trained, skilled craftworkers and contractors are paramount to the success of any tile project, and when the public’s health, safety and welfare are at stake, qualified labor is critical.
The tile industry has made great strides in the last decade in expanding the delivery of longstanding programs like the apprenticeship and training program of the International Masonry Training and Education Foundation (IMTEF) and joint apprenticeship and training committees. These programs provide union installers with training and technical expertise that reflect the latest technologies and ANSI requirements. Further, the Tile Contractors’ Association of America (TCAA)’s Trowel of Excellence certification establish credentials for best practice tile contractors who are signatory with the International Union of Bricklayers and Allied Craftworker (BAC). For installers who aspire to be the most technically proficient in their field, the Advanced Certifications for Tile Installers (ACT) assess and certify installers in seven critical skill areas, including large-format tile (LFT) and GPTP. Each of these qualified labor training and certification programs works closely with manufacturers of tile and setting materials to ensure that the union labor force is constantly kept up to date with the latest material and installation technologies. Architects can ensure qualified labor on their projects by making one or more of these credentials a requirement in their specifications.
New Code Requirements in 2021
So how large can a porcelain tile now be adhered to a facade? To simplify the new code requirements, the criteria in the 2021 IBC may be summarized as follows:
For tiles greater than ¹/₄-inch-thick (6 mm), the maximum tile size is 9 ft² (0.84 m²), which in common tile sizes is 36 x 36 inches (915 x 915 mm) or 24 x 48 inches (610 x 1,220 mm). Tiles of this thickness may not have any face longer than 48 inches (1,220 mm).
For tiles less than or equal to ¹/₄-inch-thick (6 mm), the maximum tile size is 17.5 ft² (1.6 m²), which translates to 48 x 48 inches (1,220 x 1,220 mm) or 36 x 72 inches nominally (900 x 1,800 mm in actual size). Tiles of this thickness may not have any face longer than 72 inches.
Finally, while this update applies to large and ultra-large-format tiles, it is important to remember that ceramic and porcelain tiles in traditional sizes continue to be allowed under the IBC for exteriors. With this code change, architects can now specify these larger size tiles without submitting any special requests to the local building code official. If an architect wishes to specify tiles that exceed these requirements, it may still be possible to do so with the approval of the authority having jurisdiction. This is exactly what was done on the recently completed Perry’s Steakhouse restaurant in Schaumburg, IL
Perry’s Steakhouse, designed by Aria Group Architects Inc., is a great example of ultra-large GPTP as an adhered facade. ICI was the general contractor and the tile work was performed by Ready Tile of Bartlett, IL. The panels are 40 x 117 inches and they were set in an improved, modified thinset mortar over a substrate of cementitious backer board (CBU) on heavy gauge steel studs and glass mat-reinforced gypsum sheathing. Waterproof membrane was applied in two coats directly over the CBU prior to the tile installation.
Among the many challenges was the necessity to coordinate crews of tile setters and finishers working from three lifts to reach heights of almost 30 feet, simultaneously spreading mortar on the substrate and backbuttering the tile while working from the lifts. Ready Tile LLC employed tile setters who were trained and certified for GPTP installation, an important criteria that should be included in the architectural specifications. Because the installation of GPTP requires special tools, material handling and installation techniques drastically different than those used in conventional tile installation, the training and skills of the installers were paramount to the success of this project.
“We are always looking to explore new technology and materials that help our designs,” said Brian Zielinski, AIA of Aria Group. “We faced some review board challenges in Schaumburg on exterior materials we typically use for our client, so the opportunity presented itself to use ultra-large GPTP, which we believed was the best choice to achieve our design intent. We couldn’t be happier with the outcome and are now considering the incorporation of GPTP as a standard material in the design evolution of the restaurant brand’s future locations.”
Architects and designers are encouraged to consider ceramic and porcelain tiles in all sizes, installed by qualified BAC craftworkers. The durability, low maintenance, sustainability, health benefits and unlimited design aesthetics of expertly installed tile make it the perfect choice for building facades, and it is now easier than ever to meet building code requirements and deliver a beautiful, healthy building.
Note: this article is adapted from a TCNA Bulletin written by IMI published in the 2021 Tile Council of North America Handbook for Ceramic, Glass, and Stone Tile Installation.