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

A slab has a 1/2 inch expansion joint under a new tile floor. How wide must the tile's movement joint be?

• a.No joint is needed
• b.At least 1/2 inch✓
• c.At least 1/4 inch
• d.Grout-joint width only

Joints through tile over structural joints must never be narrower than the structural joint.TCNA Handbook via CTEF

Under the VA specification, what space is left at the lip of a tub where backer board meets it?

• a.No space; butt it tight
• b.1/16 inch for thin-set
• c.1 inch for grout
• d.1/4 inch for sealant✓

The VA specification leaves a 1/4 inch space for sealant at lips of tubs, sinks and plumbing receptors.VA 09 30 13

What is the purpose of a foam backer rod in a sealant joint?

• a.Hold grout in place
• b.Waterproof the substrate
• c.Fill the joint instead of sealant
• d.Set depth; stop three-sided bond✓

Backing forms a joint enclosed on three sides at the specified depth, and sealant must bond only to two opposing surfaces.VA 07 92 00

A sealant joint is 1/4 inch wide. How deep should the sealant be under the VA specification?

• a.1/2 inch
• b.1/8 inch
• c.1/4 inch✓
• d.1 inch

At widths up to 1/4 inch, sealant depth equals width. Half-depth applies only to wider joints.VA 07 92 00

Why do acrylic latex caulks fail in tile movement joints, according to industry guidance?

• a.They stain the grout
• b.They are too flexible
• c.They cure too slowly
• d.They harden and shrink✓

Acrylic and siliconized latex caulks dry hard, shrink and fall out when the structure moves. Silicone, urethane and polysulfide are suitable.ANSI A108.01 via CTEF

White powder appears on grout lines over a slab-on-grade after a wet winter. What does it indicate?

• a.Grout that was mixed too dry
• b.Water carrying up minerals✓
• c.A sealer that is curing
• d.Normal cement dust

Efflorescence requires water to carry minerals to the surface, evaporate and leave salts. The water source must be found.CTEF, efflorescence

Under the VA stone specification, how is a damaged stone repaired?

• a.Per the stone producer✓
• b.With any color-matched epoxy
• c.By sanding it flat
• d.By sealing over the damage

Stone is repaired using methods recommended by the stone producer, and replacement stone must not show evidence of replacement.VA 09 63 40

A heated tile floor fails where a toilet was bolted down after tiling. What is the likely cause?

• a.Grout that is too thick
• b.A fastener hit the cable✓
• c.A thermostat set too low
• d.Tile that is too dense

Screws and fasteners from later trades, such as toilet bolts and door stops, are a common cause of heating cable failures.CTEF, radiant heating

A new tile floor over concrete floods 20 days after installation. What does industry guidance recommend?

• a.Ask the mortar maker✓
• b.Tear out all tile at once
• c.Seal the grout immediately
• d.Ignore it; tile is waterproof

For installations within 28 days of flooding, contact the setting materials manufacturer for an opinion on how to proceed.CTEF, flooded installations

Which shower size fails the California minimum listed in city handouts for the 2025 codes?

• a.30 × 60 inches
• b.36 × 36 inches
• c.30 × 30 inches✓
• d.32 × 32 inches

A compartment needs at least 1,024 in² and a 30-inch circle; 30 × 30 is only 900 in². A 30 × 60 receptor is exempt.CPC shower size per city handouts (2025 codes)

What minimum drain and trap size do city handouts list for a shower?

• a.2 inches✓
• b.3 inches
• c.1-1/4 inches
• d.1-1/2 inches

Showers require a minimum 2-inch drain and trap; tub-to-shower conversions increase smaller waste outlets to 2 inches.CPC per city handouts (2025 codes)

A tiled niche shelf in a shower is set dead level. What does the ANSI standard require?

• a.Slope it away from the drain
• b.Seal it instead of sloping
• c.Level is correct for shelves
• d.Slope it toward the drain✓

All horizontal ledges and rims shall slope so fluid flows toward the drain, and TCNA details extend this to seats, sills and curbs.ANSI A108.01-3.6.4 via CTEF

Why does the TCNA Handbook require a pre-slope under the pan liner of a clamping-ring drain shower?

• a.To thicken the tile bed
• b.To hold the liner flat
• c.To feed the weep holes✓
• d.To replace the mortar bed

The sloped fill under the liner lets water that passes the tile reach the drain's weep holes; without it, trapped water eventually smells.TCNA Handbook via CTEF

What slope do industry sources give for a steam shower bench?

• a.1/4 inch per 12 inches to the drain✓
• b.2 inches per foot
• c.Level
• d.1 inch per foot away from the drain

Benches and horizontal surfaces in a steam shower slope 1/4 inch per 12 inches to the drain; 2 inches per foot is the ceiling slope.TCNA SR613 via CTEF

How thick is the mortar bed placed on top of a shower pan liner under ANSI A108.01A?

• a.Thicker at the drain
• b.Tapered from 3 inches to zero
• c.A uniform 1-1/2 inches✓
• d.1/4 inch

The mortar bed over the membrane is the same thickness at the walls and at the drain, 1-1/2 inches; the pre-slope below provides the pitch.ANSI A108.01A via CTEF

In one California city's curbless-shower guideline, where must the top of the drain inlet sit?

• a.At least 1/2 inch above the floor
• b.Level with the threshold
• c.2 inches below the threshold top✓
• d.Anywhere, if sloped

The guideline requires the drain inlet top to be a minimum of 2 inches below the top of the finished threshold, so the receptor holds water.City of Mill Valley curbless shower guideline

A homeowner reports a musty odor from a shower that does not leak. What does industry guidance link this to?

• a.Epoxy grout
• b.Glass tile
• c.Too much grout sealer
• d.No pre-slope✓

Without a pre-slope, trapped and stagnant water on the liner eventually emits an offensive odor even if nothing leaks.CTEF, slope to drain

Which is one of the three categories of glass tile industry guidance describes?

• a.Low-temperature coated glass✓
• b.Quarry glass
• c.Vitreous porcelain glass
• d.Gauged glass slab

Glass tile comes as cast, fused, or low-temperature coated glass, each with different requirements.CTEF, glass tile

A glass backsplash tile is cut at an exposed end. What did the installer in the industry example do with the cut edge?

• a.Covered it with grout
• b.Polished it to match✓
• c.Left it raw
• d.Painted it

The cut edges were polished to approximate the factory edge for a consistent finish.CTEF, glass tile

Why might unsanded grout be chosen for a glass tile backsplash?

• a.Sanded grout will not bond to glass
• b.Unsanded grout is waterproof
• c.Glass needs 1/4 inch joints
• d.Sanded grout can scratch some glass✓

Some glass tiles scratch if sanded grout is used, so an unsanded grout with a narrow joint was chosen.CTEF, glass tile

What substrate flatness must be met at a minimum for gauged porcelain tile panels?

• a.1/8 inch in 10 feet✓
• b.1/16 inch in 10 feet
• c.1/2 inch in 10 feet
• d.1/4 inch in 10 feet

The A137.3/A108.19 installation requires at least the 1/8 inch in 10 feet standard for large tile.ANSI A108.19 via CTEF

In a hydronic radiant floor, what carries the heat?

• a.The grout joints
• b.Water or fluid in pipes✓
• c.Hot air ducts
• d.Resistance wires in a mat

Hydronic systems circulate water or a heat-transfer fluid through pipes; electric systems use resistance wires.CTEF, radiant heating

How far from walls and obstacles should an uncoupling membrane for a heated floor be kept?

• a.Tight against them
• b.About 1/4 inch✓
• c.About 1 foot
• d.About 3 inches

Keep the membrane a consistent 1/4 inch from any obstacle, change of plane and perimeter, the same as backer board.CTEF, radiant heating

How high does grout normally reach on a pebble-stone shower floor?

• a.Over the top of the stones
• b.Flush with the tallest stones
• c.No grout is used
• d.About one-third up✓

Grout normally extends up about one-third of the stone's height and is not intended to cover the pebbles.CTEF, slope to drain

Wood-look planks are laid in a random pattern. What risk does industry guidance flag?

• a.Too many small cuts at walls
• b.Grout that will not cure
• c.Lippage from 33–50% offsets✓
• d.Planks that absorb water

Random layouts can place offsets between 33 and 50 percent, which can cause excessive lippage.CTEF, plank tile

Which installation method does the VA specification call for in pools holding water?

• a.Latex mortar over membrane
• b.Spot-bonded epoxy
• c.A108.1C, no latex mortar✓
• d.Organic adhesive over backer

Pools holding water use A108.1C, and latex portland cement mortar is not used because latex can re-emulsify under water.VA 09 30 13

Where does the federal specification call for abrasive-surface quarry tile?

• a.Bedroom floors
• b.Shower ceilings
• c.Decorative wall panels
• d.Kitchens and coolers✓

Abrasive quarry tile is specified for vestibules, kitchens, walk-in refrigerators and work spaces behind serving lanes.UFGS 09 30 10

According to a Cal/OSHA hazard alert, about how much silica does engineered stone contain?

• a.About 10 percent
• b.Less than 1 percent
• c.About 50 percent
• d.More than 90 percent✓

The Division's alert describes engineered stone as crushed stone containing more than 90 percent silica bound with resin.Cal/OSHA hazard alert, engineered stone

Above what crystalline silica content does working artificial stone become a high-exposure trigger task under section 5204?

• a.10 percent by weight
• b.0.1 percent by weight✓
• c.50 percent by weight
• d.Any content

The trigger is 0.1 percent for artificial stone and 10 percent for natural stone.8 CCR 5204

A delivered granite slab shows a crack running into the cutout area. What does the VA stone specification direct?

• a.Use it if the crack is under 1 inch
• b.Use it facing the wall
• c.Do not use it✓
• d.Use it with the crack sealed

Stone is selected to prevent units containing cracks, seams and starts that could impair structural integrity or function.VA 09 63 40

What minimum thickness does the VA specification set for a marble threshold?

• a.1/2 inch
• b.1-1/2 inches
• c.1/4 inch
• d.3/4 inch✓

Thresholds are one piece, at least 3/4 inch thick, with at least 1/4 inch at the beveled edge.VA 09 30 13

A tile floor meets a vinyl floor 3/16 inch lower. What does ANSI A108.01 allow?

• a.A vertical edge✓
• b.A mandatory 1:2 bevel
• c.A 1-inch threshold
• d.A mandatory 1:12 ramp

Changes in level up to 1/4 inch may be vertical without edge treatment, though protecting the tile edge is advisable.ANSI A108.01-3.2.3 via CTEF

If a construction employer's Code of Safe Practices is not posted at the job site office, who must have it?

• a.Only Cal/OSHA
• b.Only the owner
• c.Each supervisor✓
• d.Only new hires

The Code is posted at each job site office or provided to each supervisory employee, who keeps it readily available.8 CCR 1509(c)

Under Cal/OSHA's construction orders, who may operate a powered wet saw on a tile job?

• a.Only licensed contractors
• b.Any worker over 16
• c.Only qualified persons✓
• d.Anyone after a demonstration

The employer shall permit only qualified persons to operate equipment and machinery.8 CCR 1510(b)

What is Cal/OSHA's permissible exposure limit for respirable crystalline silica, as an 8-hour TWA?

• a.25 μg/m³
• b.5 μg/m³
• c.100 μg/m³
• d.50 μg/m³✓

The PEL is 50 μg/m³; 25 μg/m³ is the action level.8 CCR 1532.3

What is the silica action level under section 1532.3?

• a.50 μg/m³
• b.10 μg/m³
• c.25 μg/m³✓
• d.2 μg/m³

The action level is 25 μg/m³ as an 8-hour TWA; 2 μg/m³ is the lead action level.8 CCR 1532.3

A handheld wet saw is used outdoors for three hours. What respirator does Table 1 require?

• a.APF 10
• b.None✓
• c.APF 1000
• d.APF 25

Outdoors, handheld saws with integrated water need no respirator for up to four hours; indoors they need APF 10.8 CCR 1532.3 Table 1

What controls does Table 1 require for a handheld drill boring holes in tile or concrete?

• a.Shroud and dust collector✓
• b.No controls under 1 hour
• c.Water only
• d.A fan and dry sweeping

Drills use a shroud or cowling with a dust collection system and a HEPA vacuum to clean holes, with no respirator required.8 CCR 1532.3 Table 1

A worker switches to a different make and model of tight-fitting respirator. What does section 5144 require?

• a.A written note in the file
• b.No new test until the annual date
• c.A medical exam only
• d.A new fit test before use✓

Fit testing is required before initial use, whenever a different facepiece is used, and at least annually.8 CCR 5144(f)

Noise from grinders exceeds Table N-1 limits. What must the employer try first?

• a.Nothing below 100 dBA
• b.Earplugs only
• c.Engineering/admin controls✓
• d.Longer shifts

Feasible administrative or engineering controls come first; hearing protection is provided if they do not bring levels within the table.8 CCR 5096(b)

At what outdoor temperature must shade be present for a tile crew under section 3395?

• a.Above 80°F✓
• b.Above 70°F
• c.Above 95°F
• d.Above 100°F

Shade shall be present when the temperature exceeds 80°F; high-heat procedures begin at 95°F.8 CCR 3395(d)

Within what period does acclimatization to heat peak in most people, according to section 3395?

• a.Four to fourteen days✓
• b.One day
• c.One to two hours
• d.Thirty to sixty days

Acclimatization peaks in most people within four to fourteen days of regular work in the heat.8 CCR 3395(b)

Indoors, the heat index reaches 88°F while employees are present. What does section 3396 require?

• a.Its control measures✓
• b.Nothing below 95°F
• c.Only drinking water
• d.Work must stop

When the temperature or heat index reaches 87°F, the indoor order's assessment and control measures apply.8 CCR 3396(a)(2)

Where must safety data sheets for job-site chemicals be available?

• a.At the main office only
• b.At hand every shift✓
• c.With the supplier
• d.In the owner's files

SDSs must be readily accessible during each work shift to employees in their work areas.8 CCR 5194(g)

What does three points of contact on a ladder mean under section 3276?

• a.One hand and one foot
• b.Both feet and the chest
• c.Two feet and a hand✓
• d.Two hands and a tool belt

Three-point contact is two feet and one hand, or two hands and one foot, supporting the user's weight.8 CCR 3276(e)(15)

When may a worker stand on the step just below a stepladder's topcap?

• a.Never
• b.When the ladder is under 6 feet
• c.When 18 in. below the topcap✓
• d.When someone holds the ladder

Employees may not stand on the topcap or the step below it, except that the step below may be used if it is 18 inches under the topcap.8 CCR 3276(e)(15)

At what fall distance does section 1670 require personal fall protection at an unprotected edge?

• a.More than 15 feet
• b.More than 7-1/2 feet✓
• c.More than 30 feet
• d.More than 4 feet

Personal fall arrest, restraint or positioning systems are required for falls in excess of 7-1/2 feet at unprotected sides and edges.8 CCR 1670(a)

Which temporary receptacles on a construction site must have GFCI protection under section 2405.4?

• a.Only permanent wiring
• b.None if cords are new
• c.120 V, 15/20 A temporary✓
• d.Only 240 V receptacles

All 120-volt, single-phase, 15- and 20-ampere receptacles not part of permanent wiring and in use by employees need GFCIs (or an assured grounding program).8 CCR 2405.4

What airborne lead level is Cal/OSHA's construction permissible exposure limit since January 1, 2025?

• a.10 μg/m³✓
• b.30 μg/m³
• c.2 μg/m³
• d.50 μg/m³

The amended 1532.1 sets a PEL of 10 μg/m³ as an 8-hour TWA and an action level of 2 μg/m³.8 CCR 1532.1

Where may a portable ladder's base be placed under section 3276?

• a.On secure, level footing✓
• b.On a stack of tile boxes
• c.On a barrel for height
• d.On wet mortar

The base goes on secure and level footing; ladders are not placed on boxes, barrels or other unstable bases to gain height.8 CCR 3276(e)(7)