CTI Surface Preparation & Adhesives 3

Question 1

When preparing a wood subfloor for tile installation, what is the maximum allowable deflection under live load according to TCNA?

Accepted Answer

L/360

Answer

TCNA requires a subfloor deflection of no more than L/360 of the span under live load to prevent tile and grout cracking.

Question 2

What is a primary advantage of using a medium-bed mortar over standard thin-set?

Accepted Answer

Ability to fill voids up to 3/4 inch without slumping

Answer

Medium-bed mortars are formulated to support large/heavy tiles at greater mortar depths (up to 3/4 inch) without slumping.

Question 3

An epoxy adhesive is specified for a commercial kitchen floor. What is a critical characteristic of mixing and using epoxy mortar?

Accepted Answer

It has a limited pot life and must be used within the working time

Answer

Epoxy mortars have a finite pot life once mixed; unused material hardens and must be discarded, making working time critical.

Question 4

How should existing ceramic tile be prepared before applying a new tile installation over it?

Accepted Answer

Clean, ensure bond, fill cracks, and scarify glossy surfaces

Answer

Existing tile must be cleaned, tested for bond, have cracks repaired, and glossy surfaces scarified or primed to ensure adhesion.

Question 5

What does the ANSI A118.11 standard specify?

Accepted Answer

Standard specifications for EGP (Exterior Glue Plywood) latex portland cement mortars

Answer

ANSI A118.11 covers EGP (Exterior Glue Plywood) latex portland cement mortars used for bonding tile to plywood.

(CTI) Certified Tile Installer Practice Test