CTI Surface Preparation & Adhesives 1 — Questions and Answers
Question 1: Why is surface preparation critical before tile installation?
- To change the tile color.
- To increase the tile's cost.
- To ensure a clean, level, and dry substrate (Correct answer)
- To make grout dry faster.
Correct answer: To ensure a clean, level, and dry substrate
Proper surface preparation ensures tile adhesion and prevents future tile failure.
Question 2: What is the purpose of a crack isolation membrane?
- To make the floor slippery.
- To add color to the adhesive.
- To prevent cracks in the tile caused by substrate movement (Correct answer)
- To help grout cure faster.
Correct answer: To prevent cracks in the tile caused by substrate movement
This membrane helps prevent cracks from the substrate from transferring to the tile surface.
Question 3: What is the most common adhesive used for tile installation?
- Hot glue
- Carpet adhesive
- Thinset mortar (Correct answer)
- Wood glue
Correct answer: Thinset mortar
Thinset mortar is widely used for its bonding strength and flexibility.
Question 4: Which substrate requires a primer before applying adhesive?
- Sealed concrete
- Plywood
- Gypsum board (Correct answer)
- Cement backer board
Correct answer: Gypsum board
Highly absorbent substrates like gypsum may require a primer to prevent premature drying of the adhesive.
Question 5: Why should dust be removed before adhesive application?
- It helps the adhesive spread faster.
- It enhances the color of tiles.
- It promotes strong adhesion between surface and tile (Correct answer)
- It allows tiles to slide easily.
Correct answer: It promotes strong adhesion between surface and tile
Dust prevents adhesive from bonding properly to the substrate.
Question 6: Which trowel is best for applying thinset?
- Flat trowel
- Margin trowel
- Notched trowel (Correct answer)
- Grout float
Correct answer: Notched trowel
A notched trowel is used to ensure even adhesive coverage on the tile and surface.
Question 7: What happens if adhesive is applied too thickly?
- It bonds better.
- It evens out lippage.
- It can cause tile leveling issues (Correct answer)
- It speeds up curing.
Correct answer: It can cause tile leveling issues
Excess adhesive can cause uneven tile placement and longer drying times.
Question 8: How long should adhesive cure before grouting?
- 1 hour
- 4 hours
- 24 hours (Correct answer)
- Immediately
Correct answer: 24 hours
Allowing thinset to cure for at least 24 hours prevents tile movement during grouting.
Question 9: Why use modified thinset mortar?
- It’s cheaper than unmodified.
- It requires no water.
- It enhances performance and adhesion (Correct answer)
- It dries instantly.
Correct answer: It enhances performance and adhesion
Modified thinset contains polymers that improve flexibility, bonding, and strength.
CTI Surface Preparation & Adhesives 1
Why is surface preparation critical before tile installation?