CTI Study Guide 2026

Tile thickness is a crucial specification because it directly impacts the tile's durability and the overall installation process. Thicker tiles generally offer greater strength and resistance to impact and heavy loads, making them suitable for high-traffic areas. It also affects the finished floor height and requires careful consideration for proper leveling and setting material selection to ensure a stable and long-lasting installation.

Grout haze refers to a thin, cloudy film or residue that remains on the tile surface after the grout has been applied and the initial cleaning has been performed. This haze is caused by fine grout particles that dry onto the tile surface. It typically requires specific cleaning methods and products to remove completely and restore the tile's original appearance, ensuring a clean and professional finish.

Backer rod should be approximately 1/8 to 1/4 inch larger than the joint width so it compresses slightly when inserted, ensuring a snug fit and preventing sealant from bonding to the bottom of the joint.

Sheet membrane seams must overlap at least 2 inches and be fully bonded to create a continuous, leak-free waterproofing layer.

ANSI A118.6 covers standard Portland cement grout performance requirements for tile installations.

TCNA EJ171 recommends movement joints at maximum 20–25 feet in each direction for interior tile installations to relieve built-up stresses.