CTI Grout & Mortar Systems Flashcards

Which ANSI standard establishes performance requirements for standard Portland cement grouts used in tile installations?

Answer: ANSI A118.6

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

What is the primary advantage of epoxy grout over cement-based grout in a commercial kitchen?

Answer: It provides superior chemical and stain resistance

Epoxy grout resists food acids, oils, and harsh cleaning chemicals, making it ideal for commercial kitchens where these exposures are constant.

What is the minimum cure time for thinset mortar before grout can be applied to a tile installation?

Answer: 24 hours

Thinset mortar must cure a minimum of 24 hours before grouting to develop sufficient bond strength before the grout introduces moisture and stress.

Sanded grout is required for grout joints that are at least how wide?

Answer: 1/8 inch

Sanded grout is recommended for joints 1/8 inch and wider because sand prevents the shrinkage cracking that occurs in wider unsanded joints.

A CTI inspector finds hollow voids within grout joints. What is the most likely cause?

Answer: Insufficient grout was packed into the joint depth

Hollow grout joints result from grout not being fully packed to the joint depth, leaving voids that trap moisture and promote cracking.

What is the primary benefit of adding a polymer modifier to Portland cement grout?

Answer: It enhances flexibility, bond strength, and water resistance

Polymer additives simultaneously improve the grout's flexibility, adhesion, and resistance to water penetration over standard cement-and-water grout.