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CTI Certified Ceramic Tile Installer EXAM ACTUAL
Exam ALL 200 QUESTIONS AND CORRECT
ANSWERS LATEST UPDATE THIS YEAR
CTI Exam Coverage: Full Exam Overview
• Substrate Requirements: Deflection limits (L/360 for ceramic, L/720 for stone) and
surface preparation.
• Mortar & Adhesives: Selection of thin-set, modified vs. unmodified mortars, and "Large
and Heavy Tile" (LHT) mortar.
• Layout & Installation: Trowel selection, "Back-buttering," and coverage requirements
for wet vs. dry areas.
• Expansion & Movement: ANSI A108.01 (EJ171) standards for movement joints.
• Waterproofing & Membranes: Liquid-applied vs. sheet membranes for showers and
steam rooms.
• Grouting & Cleanup: Proper water ratios, timing, and specialized grouts (Epoxy vs.
Cementitious).
CTI Certified Installer Exam: Batch 1 (Questions 1-100)
1. According to ANSI A108 standards, what is the minimum required mortar coverage for tile
installed in a "Wet Area" or for "Natural Stone" tile?
• A. 65%
• B. 80%
• C. 95%
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• D. 100%
• Answer: C. 95%
• Rationale: While dry interior walls require 80% coverage, wet areas (showers/pools)
and all natural stone installations require a minimum of 95% coverage with no voids
exceeding 2 square inches to prevent water accumulation and structural failure.
2. When installing Large Format Tile (LFT), defined as any tile with one side longer than 15
inches, what is the maximum allowable "Lippage" between adjacent tiles?
• A. 1/32 of an inch
• B. 1/16 of an inch
• C. 1/8 of an inch
• D. 1/4 of an inch
• Answer: B. 1/16 of an inch
• Rationale: ANSI A108.02 specifies that for grout joints 1/16" to 1/4", the maximum
allowable lippage for large format tile is 1/32" plus the inherent warp of the tile,
generally totaling no more than 1/16".
3. What is the primary reason the TCNA Handbook requires a 1/8-inch gap between the tile
and a vertical transition, such as a bathtub or a wall?
• A. To make it easier for the grout to flow into the corner.
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• B. To allow for the structural movement and expansion of the different materials.
• C. To prevent the tile from absorbing water from the bathtub.
• D. To provide a decorative border for the application of silicone.
• Answer: B. To allow for the structural movement and expansion of the different
materials.
• Rationale: Known as a movement joint (EJ171), these gaps must be filled with a flexible
sealant (caulk) rather than hard grout to prevent tiles from cracking or "tenting" when
the house settles or expands.
4. When preparing a wooden subfloor for tile, what is the maximum allowable "Deflection"
for a floor that will receive natural stone tile?
• A. L/360
• B. L/480
• C. L/720
• D. L/100
• Answer: C. L/720
• Rationale: Natural stone is brittle and less flexible than ceramic. It requires a stiffer floor
with half the allowable bounce (L/720) compared to ceramic tile (L/360) to prevent the
stone from snapping.
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5. Which trowel technique is considered the industry standard for ensuring maximum mortar
coverage and air release during tile installation?
• A. Swirling the trowel in a circular motion to create suction.
• B. Combing the mortar in straight, parallel lines in the shortest direction of the tile.
• C. Spot-bonding the four corners of the tile with "pats" of mortar.
• D. Applying a thick layer of mortar to the floor and none to the tile.
• Answer: B. Combing the mortar in straight, parallel lines.
• Rationale: Combing in straight lines allows air to escape when the tile is "collapsed" into
the ridges. Swirling traps air pockets (voids), which lead to hollow sounds and broken
tiles.
6. What is the specific purpose of "Back-buttering" a tile before placing it into the combed
mortar bed on the substrate?
• A. To make the tile more waterproof before it touches the wet mortar.
• B. To ensure a 100% bond by filling the deep recesses on the back of the tile.
• C. To change the color of the tile's edge to match the grout.
• D. To prevent the tile from sliding once it is placed on the wall.
• Answer: B. To ensure a 100% bond.
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CTI Certified Ceramic Tile Installer EXAM ACTUAL
Exam ALL 200 QUESTIONS AND CORRECT
ANSWERS LATEST UPDATE THIS YEAR
CTI Exam Coverage: Full Exam Overview
• Substrate Requirements: Deflection limits (L/360 for ceramic, L/720 for stone) and
surface preparation.
• Mortar & Adhesives: Selection of thin-set, modified vs. unmodified mortars, and "Large
and Heavy Tile" (LHT) mortar.
• Layout & Installation: Trowel selection, "Back-buttering," and coverage requirements
for wet vs. dry areas.
• Expansion & Movement: ANSI A108.01 (EJ171) standards for movement joints.
• Waterproofing & Membranes: Liquid-applied vs. sheet membranes for showers and
steam rooms.
• Grouting & Cleanup: Proper water ratios, timing, and specialized grouts (Epoxy vs.
Cementitious).
CTI Certified Installer Exam: Batch 1 (Questions 1-100)
1. According to ANSI A108 standards, what is the minimum required mortar coverage for tile
installed in a "Wet Area" or for "Natural Stone" tile?
• A. 65%
• B. 80%
• C. 95%
1
, Page 2 of 125
• D. 100%
• Answer: C. 95%
• Rationale: While dry interior walls require 80% coverage, wet areas (showers/pools)
and all natural stone installations require a minimum of 95% coverage with no voids
exceeding 2 square inches to prevent water accumulation and structural failure.
2. When installing Large Format Tile (LFT), defined as any tile with one side longer than 15
inches, what is the maximum allowable "Lippage" between adjacent tiles?
• A. 1/32 of an inch
• B. 1/16 of an inch
• C. 1/8 of an inch
• D. 1/4 of an inch
• Answer: B. 1/16 of an inch
• Rationale: ANSI A108.02 specifies that for grout joints 1/16" to 1/4", the maximum
allowable lippage for large format tile is 1/32" plus the inherent warp of the tile,
generally totaling no more than 1/16".
3. What is the primary reason the TCNA Handbook requires a 1/8-inch gap between the tile
and a vertical transition, such as a bathtub or a wall?
• A. To make it easier for the grout to flow into the corner.
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, Page 3 of 125
• B. To allow for the structural movement and expansion of the different materials.
• C. To prevent the tile from absorbing water from the bathtub.
• D. To provide a decorative border for the application of silicone.
• Answer: B. To allow for the structural movement and expansion of the different
materials.
• Rationale: Known as a movement joint (EJ171), these gaps must be filled with a flexible
sealant (caulk) rather than hard grout to prevent tiles from cracking or "tenting" when
the house settles or expands.
4. When preparing a wooden subfloor for tile, what is the maximum allowable "Deflection"
for a floor that will receive natural stone tile?
• A. L/360
• B. L/480
• C. L/720
• D. L/100
• Answer: C. L/720
• Rationale: Natural stone is brittle and less flexible than ceramic. It requires a stiffer floor
with half the allowable bounce (L/720) compared to ceramic tile (L/360) to prevent the
stone from snapping.
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, Page 4 of 125
5. Which trowel technique is considered the industry standard for ensuring maximum mortar
coverage and air release during tile installation?
• A. Swirling the trowel in a circular motion to create suction.
• B. Combing the mortar in straight, parallel lines in the shortest direction of the tile.
• C. Spot-bonding the four corners of the tile with "pats" of mortar.
• D. Applying a thick layer of mortar to the floor and none to the tile.
• Answer: B. Combing the mortar in straight, parallel lines.
• Rationale: Combing in straight lines allows air to escape when the tile is "collapsed" into
the ridges. Swirling traps air pockets (voids), which lead to hollow sounds and broken
tiles.
6. What is the specific purpose of "Back-buttering" a tile before placing it into the combed
mortar bed on the substrate?
• A. To make the tile more waterproof before it touches the wet mortar.
• B. To ensure a 100% bond by filling the deep recesses on the back of the tile.
• C. To change the color of the tile's edge to match the grout.
• D. To prevent the tile from sliding once it is placed on the wall.
• Answer: B. To ensure a 100% bond.
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