CSLB C-54 Ceramic and Mosaic Tile (Trade Exam) — All Questions

A kitchen floor measures 7 ft 6 in. by 10 ft. What is its area?

• a.76 ft²
• b.75 ft²✓
• c.86 ft²
• d.70 ft²

7 ft 6 in. is 7.5 ft, and 7.5 × 10 = 75 ft². Reading 7 ft 6 in. as 7.6 ft gives 76 ft², the common error of treating inches as tenths of a foot.NIST Handbook 44, App. C (units)

How many 2 × 8 inch tiles cover one square foot, ignoring joints?

• a.16
• b.12
• c.8
• d.9✓

A 2 × 8 tile covers 16 square inches; 144 ÷ 16 = 9 tiles per square foot. 16 is the tile's area, not a tile count.NIST Handbook 44, App. C (144 in² = 1 ft²)

On a plan drawn at 1/2 inch = 1 foot, a wall measures 2-1/2 inches long. How long is the wall?

• a.10 ft
• b.2.5 ft
• c.1.25 ft
• d.5 ft✓

At 1/2 inch = 1 foot, each inch of paper is 2 feet, so 2-1/2 inches is 5 feet. 1.25 ft comes from dividing by 2 instead of multiplying.Plan scale arithmetic

A 320 ft² floor gets 12 × 24 inch tile with a 10 percent waste allowance. How many tiles are needed?

• a.160
• b.176✓
• c.352
• d.320

Each 12 × 24 tile covers 2 ft². 320 × 1.10 = 352 ft², and 352 ÷ 2 = 176 tiles. 352 is the square footage with waste, not the tile count.NIST Handbook 44, App. C

A job needs 188 ft² of tile including waste, and each carton holds 11.6 ft². How many cartons must be ordered?

• a.18
• b.17✓
• c.16
• d.11

188 ÷ 11.6 = 16.2, and partial cartons cannot be bought, so order 17. Rounding down to 16 leaves the job short.Estimating arithmetic

A 10 × 12 ft room gets cove base on all walls except a 3 ft door opening. How many linear feet of base are needed?

• a.44 lin ft
• b.120 lin ft
• c.38 lin ft
• d.41 lin ft✓

The perimeter is 2 × (10 + 12) = 44 ft; subtract the 3 ft opening for 41 linear feet. 120 is the room's area, not a linear measure.Estimating arithmetic

An installer lays 40 ft² per hour. How many hours does a 500 ft² floor take?

• a.12 hours
• b.12.5 hours✓
• c.8 hours
• d.20 hours

Hours equal area divided by production rate: 500 ÷ 40 = 12.5. Rounding to 12 drops half an hour of paid labor.Estimating arithmetic

A shower drain sits 30 inches from the farthest corner. At 1/4 inch per foot, how much must the pre-slope rise to that corner?

• a.1/4 inch
• b.1-1/4 inches
• c.7-1/2 inches
• d.5/8 inch✓

30 inches is 2.5 feet; 2.5 × 1/4 inch = 5/8 inch. 7-1/2 inches comes from multiplying 30 by 1/4 without converting inches to feet.Plumbing code slope as described by CTEF

A 4 × 6 ft shower floor gets a 1-1/2 inch mortar bed. What volume of mortar is that?

• a.36 ft³
• b.1.5 ft³
• c.3 ft³✓
• d.6 ft³

Area 24 ft² × 0.125 ft (1.5 in ÷ 12) = 3 ft³. 36 comes from multiplying by 1.5 without converting the thickness to feet.NIST Handbook 44, App. C

Which submittal shows the proposed tile pattern at inside and outside corners and around items mounted on the tile?

• a.Product data sheets
• b.Shop (detail) drawings✓
• c.Material certificates
• d.Warranty letter

Federal tile specifications ask for detail drawings showing the pattern at corners, terminations and mounted equipment. Product data describe materials, not how they are laid out.UFGS 09 30 10, submittals

Glazed ceramic wall tile made for interior walls typically falls in which water-absorption class?

• a.Non-vitreous✓
• b.Vitreous
• c.Semi-vitreous
• d.Impervious

Glazed wall tile is typically non-vitreous, absorbing 7 percent or more, and is recommended for walls only. Impervious describes porcelain.ANSI A137.1 via UFGS 09 30 10

A tile tested at 0.3 percent water absorption belongs to which class?

• a.Vitreous
• b.Semi-vitreous
• c.Impervious✓
• d.Non-vitreous

Impervious tile absorbs less than 0.5 percent; porcelain is typically impervious. Vitreous is 0.5 to 3.0 percent.ANSI A137.1 via UFGS 09 30 10

Under the federal tile specification's note, where should a tile with a wet DCOF below 0.42 be installed?

• a.Commercial kitchens
• b.Any level interior floor
• c.Floors kept dry in use✓
• d.Exterior walkways and ramps

The note says tiles under 0.42 wet DCOF should only be installed where the surface will be kept dry when walked upon, with safe cleaning procedures. A commercial kitchen is a floor expected to be walked on wet, where 0.42 is the threshold minimum.UFGS 09 30 10; ANSI A137.1

Where may 6 mm (1/4 inch) gauged porcelain tile be used, according to the federal tile specification's note?

• a.Floors, walls, counters✓
• b.Walls only
• c.Countertops only
• d.Exterior walls only

The note says 6 mm gauged porcelain is suitable for floors, walls and counter tops, while 3 mm is for walls only.UFGS 09 30 10 (ANSI A137.3/A108.19)

Tile arrives with opened cartons and torn labels. What does the federal specification require of delivered materials?

• a.Any cartons, if the tile is uncracked
• b.Resealed cartons with new labels
• c.Unopened containers with labels intact✓
• d.Loose tile on pallets

Materials are to be delivered in the manufacturer's original unopened containers with seals unbroken and labels intact. Resealing does not restore the identification.UFGS 09 30 10, delivery

Which ANSI standard covers an EGP (exterior glue plywood) modified dry-set mortar?

• a.A118.11✓
• b.A136.1
• c.A118.6
• d.A118.1

A118.11 is the EGP latex-portland cement mortar for plywood. A118.1 is unmodified dry-set mortar and A118.6 is standard cement grout.ANSI A118.11

A floor has 3/16 inch grout joints. Which grout type fits the joint width?

• a.Latex caulk
• b.Sanded grout✓
• c.Unsanded grout
• d.Organic adhesive

Sanded grout is used for joints 1/8 inch or wider; unsanded grout is for joints 1/8 inch or narrower.VA 09 63 40 spec note

Before bidding, a contractor finds the drawings show no movement joints in a large tile floor. What is the correct action?

• a.Omit them to match the drawings
• b.Send the designer an RFI✓
• c.Add grout joints at 40 feet
• d.Wait and ask the inspector

Movement joint locations are the design professional's call, so the gap goes to the architect in writing. Omitting them is the tempting reading of the drawings, but EJ171 treats movement joints as required.TCNA EJ171 via CTEF