CTI Grouting & Finishing Techniques 2

Question 1

When grouting a floor with large-format tiles (24"x24" or larger), which grout joint width is typically the minimum recommended to allow for lippage tolerance?

Accepted Answer

1/8 inch

Answer

Large-format tiles generally require a minimum 1/8-inch grout joint to accommodate slight warpage and lippage inherent in manufacturing.

Question 2

What is the primary purpose of back-buttering tile edges before grouting a stone installation?

Accepted Answer

To fill voids left by the notched trowel

Answer

Back-buttering tile edges before grouting fills voids beneath tile edges that notched trowel ridges may not have fully covered.

Question 3

Efflorescence appearing on a grouted tile surface is caused by:

Accepted Answer

Soluble salts carried to the surface by water migration

Answer

Efflorescence is a white crystalline deposit formed when water carries soluble salts through the grout and they crystallize on the surface as water evaporates.

Question 4

Which tool is best suited for packing grout into joints on a mosaic tile installation with small joints?

Accepted Answer

A hard rubber float

Answer

A hard rubber float provides the firmness needed to force grout deeply into the small joints of mosaic installations without tearing the mesh backing.

Question 5

After grouting, you notice grout haze has dried on a polished marble surface. What should you use to remove it?

Accepted Answer

A manufacturer-approved grout haze remover safe for natural stone

Answer

Only a stone-safe, non-acidic grout haze remover should be used on polished marble, as acids and abrasive pads will permanently damage the finish.

(CTI) Certified Tile Installer Practice Test

(CTI) Certified Tile Installer Practice Test

CTI Grouting & Finishing Techniques 2