less than three tiles or tile assem- blies are removed for inspection. • Check tiles for presence of exces- sive white powder (manufacturer’s release agent) on back of tile. If necessary, brush or remove white powder before attempting to bond tile. • Porcelain tiles have extremely low water absorption rates. As a result, the setting time of many latex-Portland cement mortars may be extended. Therefore, working on or exposing the installation to traffic prior to a good bond forming may result in poor performance of the completed job. • Proceed with caution when installing large porcelain tiles over substrates subject to bending or deflection. When installing materi- als with special or unique proper- ties, the code minimum may not be sufficient to provide satisfactory performance. Each project presents its own conditions; consult with owner or builder to determine if any modifications to the structure can be done prior to the installation when you suspect problems or have concerns. • Web floor trusses and engineered I-joists are used in ways that weren’t possible with traditionally sawn lumber. Be aware of the conditions you face prior to installation so adjustments can be made if nec- essary. See NTCA’s document on Installations over Engineered Wood Products for additional information. • Require architect or construction manager to locate movement joints in tile work as recommended in the TCNA Handbook. Design, loca- tions, spacing, and actual instal- lation must conform with require- ments in the TCNA Handbook and ANSI Standards. Movement joint recommendations apply to residen- tial construction as well as com- mercial and industrial construction. LARGE FORMAT TILE ––––––––––––––––––––––––––––––––––––––––––––––––– 86 TileLetter | May 2017