CTI CTI Grout & Mortar Systems 1 — Questions and Answers
Question 1: Which ANSI standard establishes performance requirements for standard Portland cement grouts used in tile installations?
- ANSI A108.10
- ANSI A118.6 (Correct answer)
- ANSI A137.1
- ANSI A108.01
Correct answer: ANSI A118.6
ANSI A118.6 covers standard Portland cement grout performance requirements for tile installations.
Question 2: What is the primary advantage of epoxy grout over cement-based grout in a commercial kitchen?
- It is easier to mix and apply
- It costs significantly less per square foot
- It provides superior chemical and stain resistance (Correct answer)
- It offers greater flexibility for movement accommodation
Correct 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.
Question 3: What is the minimum cure time for thinset mortar before grout can be applied to a tile installation?
- 2 hours
- 24 hours (Correct answer)
- 48 hours
- 72 hours
Correct 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.
Question 4: Sanded grout is required for grout joints that are at least how wide?
- 1/16 inch
- 1/8 inch (Correct answer)
- 3/16 inch
- 1/4 inch
Correct 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.
Question 5: A CTI inspector finds hollow voids within grout joints. What is the most likely cause?
- Grout was mixed too stiff
- Insufficient grout was packed into the joint depth (Correct answer)
- Tiles were spaced too closely together
- Wrong grout color was selected for the tile type
Correct 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.
Question 6: What is the primary benefit of adding a polymer modifier to Portland cement grout?
- It speeds up the grout cure time
- It enhances flexibility, bond strength, and water resistance (Correct answer)
- It lightens the grout color for better aesthetics
- It eliminates the need for sealing the finished grout
Correct 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.
CTI CTI Grout & Mortar Systems 1
Which ANSI standard establishes performance requirements for standard Portland cement grouts used in tile installations?