CFI Tile & Stone Installation 3

Question 1

Which type of mortar is specifically designed for use with glass tile installations?

Accepted Answer

White non-sanded polymer-modified mortar

Answer

White non-sanded polymer-modified mortar prevents color show-through and provides the flexibility needed for glass tiles.

Question 2

What should an installer do when encountering a crack in a concrete substrate before installing tile?

Accepted Answer

Apply a crack isolation membrane over the crack

Answer

A crack isolation membrane prevents existing cracks from reflecting through the tile assembly.

Question 3

When setting a 12-inch tile, what size V-notch trowel is typically specified to achieve proper mortar ridge collapse and coverage?

Accepted Answer

1/4" x 3/8" x 1/4"

Answer

A 1/4" x 3/8" x 1/4" V-notch trowel provides sufficient mortar volume for 12-inch tiles to achieve full contact when collapsed.

Question 4

What is the correct sequence of steps when installing a mortar bed (mud bed) for tile?

Accepted Answer

Apply cleavage membrane, pack mortar, screed to grade, allow to cure, then tile

Answer

The proper sequence is membrane, pack, screed, then allow the bed to cure before tiling to prevent settlement.

Question 5

When installing natural stone tile on a floor, why is a penetrating sealer applied before grouting?

Accepted Answer

To prevent grout from staining the stone surface

Answer

Penetrating sealers protect porous stone from grout staining during the grouting process.

(CFI) Certified Flooring Installer Practice Test