CSLB C-17 Glazing (Trade Exam) — All Questions

A sheet is 72 by 120 inches. Lites are 34 by 50 inches. In straight rows in either orientation, how many lites come from one sheet?

• a.5 lites
• b.6 lites
• c.3 lites
• d.4 lites✓

The first layout gives 2 across (72 ÷ 34) by 2 down (120 ÷ 50) for 4, and the rotated layout gives 1 across by 3 down for 3. Six would need three lites across 72 inches, which does not fit, and five would need a layout that neither orientation has room for.CSLB C-17 study guide 13E-17 (job-related calculations)

Lites of 18 by 24 inches are cut from a 60-by-80-inch sheet in straight rows, either orientation. How many fit on the sheet?

• a.8 lites
• b.10 lites
• c.9 lites✓
• d.12 lites

The first layout gives 3 across (60 ÷ 18) by 3 down (80 ÷ 24) for 9, and the rotated layout gives 2 by 4 for 8. Twelve would need four lites across 60 inches at 18 inches each, which does not fit, and ten needs a tenth lite that neither orientation has room for.CSLB C-17 study guide 13E-17 (job-related calculations)

A sheet costs $240 and yields 6 lites. What is the glass cost of one lite?

• a.$24
• b.$6
• c.$40✓
• d.$4

240 ÷ 6 = $40 per lite. The 6 is the number of lites, $4 divides by 60 instead of 6, and 24 shifts the decimal.CSLB C-17 study guide 13E-17 (job-related calculations)

A job costs $12,000. What is the price at a 15% markup?

• a.$12,180
• b.$13,800✓
• c.$14,118
• d.$13,500

Markup is on cost, so 12,000 × 1.15 = $13,800. The $14,118 is the price for a 15% margin, $12,180 adds 1.5 percent, and $13,500 adds 12.5 percent.CSLB C-17 study guide 13E-17 (job-related calculations)

A job is priced at $9,000 and the margin is 20 percent of the price. What is the cost?

• a.$7,200✓
• b.$10,800
• c.$11,250
• d.$7,500

The margin is 20 percent of price, so cost is 9,000 × 0.80 = $7,200. The $7,500 divides the price by 1.20 as if it were a markup, $11,250 divides the price by 0.80, and $10,800 adds the margin to the price.CSLB C-17 study guide 13E-17 (job-related calculations)

A job costs $5,000 and the price is $6,250. What markup does that represent?

• a.125 percent
• b.20 percent
• c.25 percent✓
• d.12.5 percent

Profit is $1,250 and 1,250 ÷ 5,000 = 25 percent of cost. Twenty percent is the margin on price, 12.5 percent halves the markup, and 125 percent is the price as a percentage of cost.CSLB C-17 study guide 13E-17 (job-related calculations)

A job costs $8,000 and the price is $10,000. What margin does that represent?

• a.20 percent✓
• b.25 percent
• c.125 percent
• d.80 percent

Profit is $2,000 and 2,000 ÷ 10,000 = 20 percent of price. Twenty-five percent is the markup on cost, 80 percent is the cost share of the price, and 125 percent is the price as a share of cost.CSLB C-17 study guide 13E-17 (job-related calculations)

A contractor wants a 25 percent margin on a $15,000 cost. What price is needed?

• a.$3,750
• b.$18,750
• c.$19,000
• d.$20,000✓

Price is cost ÷ (1 − 0.25) = 15,000 ÷ 0.75 = $20,000. The $18,750 is a 25 percent markup, $3,750 is 25 percent of cost, and $19,000 is a guess.CSLB C-17 study guide 13E-17 (job-related calculations)

Four glaziers work an 8-hour day at $55 per hour each. What is the labor cost for the day?

• a.$1,760✓
• b.$7,040
• c.$440
• d.$220

4 × 8 × 55 = $1,760. The $440 is one glazier for a day, $220 is one glazier for 4 hours, and $7,040 multiplies by four again.CSLB C-17 study guide 13E-17 (job-related calculations)

Material is $3,200, labor $2,400 and equipment $400. Overhead is 10 percent of direct cost and profit is 8 percent of cost plus overhead. What is the price?

• a.$6,480
• b.$7,128✓
• c.$6,600
• d.$7,080

Direct cost is $6,000, overhead is $600, cost plus overhead is $6,600, profit is $528, and the price is $7,128. The $7,080 figures profit on direct cost, $6,600 omits profit, and $6,480 adds 8 percent to direct cost with no overhead.CSLB C-17 study guide 13E-17 (job-related calculations)

A two-person crew sets 6 lites per day. How many working days does a 45-lite job take?

• a.15 days
• b.9 days
• c.8 days✓
• d.23 days

45 ÷ 6 = 7.5, and a partial day is a working day, so 8. 9 adds a spare day, 15 treats the crew rate as per person, and 23 divides by two instead of six.CSLB C-17 study guide 13E-17 (job-related calculations)

Installing a lite takes 0.75 labor hours and there are 60 lites. Labor is $60 per hour. What is the labor cost?

• a.$3,600
• b.$270
• c.$2,700✓
• d.$45

60 × 0.75 = 45 hours, and 45 × 60 = $2,700. The 45 is hours, $3,600 uses a full hour per lite, and $270 shifts the decimal.CSLB C-17 study guide 13E-17 (job-related calculations)

A horizontal member spans 6 feet. What deflection limit does L/175 give?

• a.About 0.30 inch
• b.About 0.41 inch✓
• c.About 0.25 inch
• d.About 0.125 inch

The span is 72 inches and 72 ÷ 175 = 0.411 inch. The 0.30 inch is the L/240 value, 1/8 inch is the sill-under-glass limit, and 0.25 is not a rule value.Pilkington ATS-192 General glazing guidelines (2013)

A horizontal member spans 16 feet. Using the lesser of L/175 and 3/4 inch, what is the limit?

• a.0.75 inch✓
• b.1.10 inches
• c.0.55 inch
• d.0.125 inch

L/175 gives 192 ÷ 175 = 1.10 inches, which is more than 3/4 inch, so the cap of 3/4 inch controls. The 1.10 ignores the cap, 1/8 inch is another limit, and 0.55 is an 8-foot value.Pilkington ATS-192 General glazing guidelines (2013)

An opening is 30 by 40 inches. What should its diagonals measure?

• a.60 inches
• b.2,500 inches
• c.70 inches
• d.50 inches✓

The diagonal is √(30² + 40²) = √2,500 = 50 inches. The sum of the sides is 70, 60 is twice the short side, and 2,500 is the sum of the squares.CSLB C-17 study guide 13E-17 (measurements and calculations)

An opening's diagonals measure 84-1/4 and 84-7/16 inches. The guideline allows 1/8 inch of difference. What is the result?

• a.It passes, because the difference is under 1/4 inch
• b.It fails, because the difference is 3/16 inch✓
• c.It passes, because both diagonals are over 84 inches
• d.It fails, because the difference is 1/4 inch

84-7/16 minus 84-1/4 is 3/16 inch, which is more than 1/8 inch. A 1/4-inch allowance is not the guideline, the size of the diagonals does not matter, and the difference is not 1/4 inch.Pilkington ATS-192 General glazing guidelines (2013)

Using 25.4 millimeters per inch, what is a 6 mm lite closest to in nominal fractions?

• a.3/8 inch
• b.1/4 inch✓
• c.1/8 inch
• d.6 inches

6 ÷ 25.4 = 0.236 inch, closest to 1/4 inch. One-eighth is about 3 mm, 3/8 is about 10 mm, and 6 inches confuses the units.CSLB C-17 study guide 13E-17 (job-related calculations)

A framing member is 2.5 inches wide. What is that in millimeters?

• a.6.35 mm
• b.0.098 mm
• c.63.5 mm✓
• d.25.4 mm

2.5 × 25.4 = 63.5 millimeters. The 6.35 shifts the decimal one place, 0.098 divides by 25.4 instead of multiplying, and 25.4 is one inch.CSLB C-17 study guide 13E-17 (job-related calculations)

An insulating unit's air space is reported as 13.2 mm. What is that closest to in inches?

• a.1/2 inch✓
• b.1/4 inch
• c.1/8 inch
• d.3/4 inch

13.2 ÷ 25.4 = 0.52 inch, closest to 1/2 inch. A quarter inch is about 6 mm, 3/4 inch is about 19 mm, and an eighth is about 3 mm.CSLB C-17 study guide 13E-17 (job-related calculations)

A 15-foot aluminum member warms by 100°F and the coefficient given is 0.0000128 inch per inch per degree. How much does it grow?

• a.About 0.12 inch
• b.About 0.0023 inch
• c.About 0.23 inch✓
• d.About 0.023 inch

The length is 180 inches and 180 × 0.0000128 × 100 = 0.230 inch. The 0.0023 shifts the decimal down two places, 0.023 shifts it down one, and 0.12 halves the result.CSLB C-17 study guide 13E-17 (job-related calculations)

Top, middle and bottom width readings of an opening are 35-7/8, 36 and 36-1/8 inches. Which width is used to size the frame?

• a.36 inches
• b.35-7/8 inches✓
• c.36-1/8 inches
• d.36-1/16 inches

The smallest reading controls because the frame must fit the tightest point. The 36 inches is the middle reading and would bind at the narrow top, 36-1/8 is the widest reading and binds worse, and 36-1/16 is a figure between them that still exceeds the narrowest reading by 3/16 inch.UFGS 08 41 13 (verify openings); CSLB C-17 study guide 13E-17

Which measurement shows whether an opening is square?

• a.The width of the opening taken at the middle
• b.The height of the opening taken at one jamb
• c.The length of the sill measured end to end
• d.Both diagonals, measured corner to corner✓

Equal diagonals mean the opening is square, and the guideline allows a 1/8-inch difference. A single width, the sill length or one jamb height says nothing about squareness.Pilkington ATS-192 General glazing guidelines (2013)

A rough opening is 60 by 48 inches and the perimeter joint is 3/8 inch on each side. What is the frame size?

• a.60-3/4 by 48-3/4 inches
• b.59-1/4 by 47-1/4 inches✓
• c.60 by 48 inches
• d.59-5/8 by 47-5/8 inches

Two joints reduce each dimension by 3/4 inch, giving 59-1/4 by 47-1/4. Subtracting one joint gives 59-5/8 by 47-5/8, a frame equal to the opening leaves no joint, and adding the joints makes a frame too big.CSLB C-17 study guide 13E-17 (measurements and calculations)

A frame is to fit a 120-by-96-inch rough opening with a 1/4-inch joint all around. What size is the frame?

• a.120-1/2 by 96-1/2 inches
• b.119-1/2 by 95-1/2 inches✓
• c.119-3/4 by 95-3/4 inches
• d.120 by 96 inches

Two 1/4-inch joints reduce each dimension by 1/2 inch. Subtracting one joint gives 119-3/4, a frame equal to the opening leaves no joint, and adding joints makes the frame too big.CSLB C-17 study guide 13E-17 (measurements and calculations)

A 16-foot run has two jambs and two intermediate mullions, each face 2-1/2 inches, with three equal lites. What is each daylight opening width?

• a.About 60.7 inches✓
• b.About 64 inches
• c.About 67 inches
• d.About 62.5 inches

The run is 192 inches, four faces take 10 inches, and 182 ÷ 3 = 60.7 inches. Dividing 192 by three ignores the faces, 67 adds the faces, and 62 deducts too little.CSLB C-17 study guide 13E-17 (measurements and calculations)

A 20-foot run has two jambs and three intermediate mullions, each face 2 inches, with four equal lites. What is each daylight opening width?

• a.62.5 inches
• b.57.5 inches✓
• c.60 inches
• d.59.5 inches

The run is 240 inches, five faces take 10 inches, and 230 ÷ 4 = 57.5 inches. Dividing 240 by four ignores the faces, 62.5 adds the faces, and 59.5 deducts only one face.CSLB C-17 study guide 13E-17 (measurements and calculations)

Each daylight opening is 57-1/2 inches wide and the bite is 3/8 inch on each side. What is the glass width?

• a.57-7/8 inches
• b.57-1/2 inches
• c.59 inches
• d.58-1/4 inches✓

Two bites add 3/4 inch, giving 58-1/4 inches. The daylight opening alone ignores the bite, 57-7/8 adds one bite, and 59 adds 1-1/2 inches.CSLB C-17 study guide 13E-17 (measurements and calculations)

A skylight lite of 1/2-inch glass is sloped 25 degrees from horizontal. What dead load does the code formula give?

• a.3.25 pounds per square foot
• b.5.9 pounds per square foot
• c.6.5 pounds per square foot✓
• d.4.9 pounds per square foot

At 30 degrees or less from horizontal D = 13 × 0.5 = 6.5 with no cosine. Applying the cosine gives 5.9, 3.25 halves it, and 4.9 uses a 3/8-inch lite.2025 CBC §2404.2

A skylight lite of 1/4-inch glass is sloped 40 degrees from horizontal. What dead load does the code formula give?

• a.About 3.25 pounds per square foot
• b.About 2.1 pounds per square foot
• c.About 2.5 pounds per square foot✓
• d.About 1.6 pounds per square foot

Steeper than 30 degrees, D = 13 × 0.25 × cos 40° = 3.25 × 0.766 = 2.5. Omitting the cosine gives 3.25, using cos 50° gives 2.1, and 1.6 has no basis.2025 CBC §2404.2

Which lite is sloped glazing under the Building Code?

• a.A lite exactly 15 degrees from vertical
• b.A lite 10 degrees from vertical
• c.A vertical lite
• d.A lite 20 degrees from vertical✓

Sloped glazing is glass sloped more than 15 degrees from vertical, so 20 qualifies. Ten degrees, exactly 15 degrees and a vertical lite do not exceed 15.2025 CBC §2404.2, §2405.1

A glass edge is 10 feet long. What is the code's limit on framing deflection perpendicular to the glass at that edge?

• a.About 0.50 inch
• b.About 0.75 inch
• c.About 1.2 inches
• d.About 0.69 inch✓

For edges up to 13 feet 6 inches the limit is 1/175 of the edge length, 120 ÷ 175 = 0.69 inch. The 3/4 inch is a manufacturer cap, 0.50 is a different fraction, and 1.2 inches is L/100.2025 CBC §2403.3

A glass edge is 16 feet long. What is the code's limit on framing deflection at that edge?

• a.About 1.05 inches✓
• b.About 0.75 inch
• c.About 1.10 inches
• d.About 0.80 inch

Over 13 feet 6 inches the limit is 1/240 of the edge length plus 1/4 inch, 192 ÷ 240 + 0.25 = 1.05 inches. The 1.10 is L/175, 0.80 omits the quarter inch, and 0.75 is the manufacturer cap.2025 CBC §2403.3

Framing bow measured over a 4-foot length is 3/32 inch. The guideline allows 1/16 inch in any four-foot length. What is the result?

• a.It is irrelevant to glazing
• b.It exceeds the limit✓
• c.It meets the limit if shimmed
• d.It meets the limit

3/32 inch is more than 1/16 inch, so the bow is out of tolerance. Shimming does not remove bow in the member, and bow is a framing tolerance that matters to glass support.Viracon Glazing Guidelines - Standard

The guideline limits twist of a horizontal sill under glass weight to what?

• a.No limit applies to sills under glass weight
• b.Less than 1 degree between ends and center✓
• c.Up to 1/2 inch between ends and center
• d.Up to 5 degrees of twist between ends and center

Sill twist is limited to less than 1 degree to avoid mechanical bending stress at the glass edge. Five degrees and 1/2 inch are far looser, and a limit does apply.Pilkington ATS-192 General glazing guidelines (2013)

Which condition can cause thermal stress breakage of annealed glass?

• a.A large sign fastened to one part of the lite✓
• b.Setting blocks at the quarter points of the sill
• c.Even sun falling across the whole lite all day
• d.A clean glazing pocket with open weeps

Signs fastened to the glass interfere with uniform solar heating, a named cause of thermal stress. Uniform sun, a clean pocket and correct blocks are not causes.Pilkington ATS-192 General glazing guidelines (2013)

How far from full closure do lock stops hold louver blinds near insulating glass to limit thermal stress?

• a.About 5 degrees
• b.Fully closed
• c.About 60 degrees
• d.About 30 degrees✓

Lock stops keeping blades about 30 degrees off full closure are described as effective. Five degrees is almost closed, 60 degrees is not the described setting, and fully closed traps heat.Pilkington ATS-192 General glazing guidelines (2013)

What is a mullion?

• a.A frame member that joins two windows into one unit✓
• b.The frame member that runs across the top of an opening
• c.The strip that holds the glass in its glazing pocket
• d.A sloped sill member that is shaped to drain water

A mullion is a frame member used to join two windows into one fenestration unit. The member across the top is a head, a sloped drainage member is a sill flashing or sill pan, and the strip that holds glass is a stop or bead.2025 Energy Code residential compliance manual, Ch. 3

A daylight opening is 80 inches wide and the system says weeps are at the quarter points of the daylight opening. Where are the two weeps measured from one end?

• a.At 40 inches
• b.At 27 inches and 53 inches
• c.At 10 inches and 70 inches
• d.At 20 inches and 60 inches✓

Quarter points of 80 inches are at 20 and 60 inches. A single weep at 40 is the center, 10 and 70 are an eighth from each end, and 27 and 53 are thirds.YKK AP storefront weathering/sealant checklist 02-4100-05

What diameter are the sill flashing weep holes in one storefront manufacturer's checklist?

• a.1 inch
• b.3/4 inch
• c.1/8 inch
• d.5/16 inch✓

The checklist calls for 5/16-inch holes at the quarter points of the daylight opening. One-eighth inch clogs, and 3/4 and 1 inch are far too large.YKK AP storefront weathering/sealant checklist 02-4100-05

Why must setting blocks be set clear of weep holes?

• a.Blocked weeps trap water and cause seal failure✓
• b.Blocks swell and bind when they touch water
• c.Weeps are sized only for air movement in the pocket
• d.Blocks must stay dry for the sealant to bond

Water trapped in the pocket leads to ponding, a primary cause of seal failure in insulating glass units. The guideline does not say blocks swell in water, dryness of the block is not the reason for keeping weeps clear, and weeps are sized to drain water, not just to move air.Pilkington ATS-192 General glazing guidelines (2013)

When is the joinery of a storefront frame sealed?

• a.Before the frame members are assembled✓
• b.Not at all, if the joints are tight
• c.After the glass has been set and stopped
• d.After the frame is set in the opening

Sealant goes on member ends before assembly so the inside of the joint is sealed. Sealing after the frame is set or after glazing reaches only the outside of the joint, and tight-fitting joints still leak without sealant.YKK AP storefront weathering/sealant checklist 02-4100-05

Just before the frame is set on the sill flashing, what does the checklist place along the back leg of the flashing?

• a.A bead of sealant✓
• b.A strip of paper
• c.A foam spacer
• d.A row of shims

A bead of sealant along the top of the flashing's back leg goes down just before the frame is set. Paper, shims and foam do not seal the joint.YKK AP storefront weathering/sealant checklist 02-4100-05

What gap does the checklist allow at a sill flashing splice?

• a.1/32 inch between the members
• b.1/8 inch between members
• c.2 inches between the members
• d.3/8 inch between members✓

The checklist allows a 3/8-inch splice joint between flashing members, sealed with a splice sleeve. An eighth of an inch and 1/32 inch leave too little room for movement, and 2 inches is far too wide.YKK AP storefront weathering/sealant checklist 02-4100-05

What are water deflectors installed on, according to the checklist?

• a.The face of the glass in the lite
• b.The top of the head member only
• c.The heads of the anchors
• d.The end of each horizontal member✓

The checklist directs water deflectors on the end of each horizontal member, sealed along three edges. They are not placed on the head only, the glass face or the anchors.YKK AP storefront weathering/sealant checklist 02-4100-05

How are vertical and horizontal glazing gaskets arranged at a corner in the checklist?

• a.Gaskets stop short of the corner to allow movement
• b.Horizontals run through and the verticals butt to them
• c.Verticals run through; horizontals butt and are sealed✓
• d.Gaskets are mitered at the corner and left unsealed

Vertical gaskets run through and the ends of horizontal gaskets are sealed to them. Running the horizontals through reverses the checklist, mitering without sealant leaves a leak path at the joint, and stopping short of the corner leaves an open gap.YKK AP storefront weathering/sealant checklist 02-4100-05

What is structural sealant glazing?

• a.Glass held in place by screws through the lite
• b.Glass held in the frame by compression gaskets alone
• c.Glass bedded and face-puttied in a steel sash frame
• d.Glass bonded by silicone that carries the loads✓

Structural sealant glazing uses silicone on one or more sides of the unit for the structural transfer of loads from glass to its support. Gasket-only, putty and through-glass screws are other methods.Viracon Glazing Guidelines - Standard

For school and hospital work, what design stress cap and minimum factor of safety does the code set for structural sealant glazing?

• a.20 psi and a factor of safety of 5✓
• b.100 psi and a factor of safety of 1
• c.5 psi and a factor of safety of 20
• d.200 psi and a factor of safety of 2

The code's provisions for those jurisdictions cap allowable stress at 20 psi and require a factor of safety of at least 5. The other pairs are not the code values.2025 CBC §2410.1.1

Holes for door patch fittings in tempered glass must be located and confirmed when?

• a.After glazing, by core drilling the lite on site
• b.Before the glass is ordered and fabricated✓
• c.After the glass arrives, by drilling on site
• d.At glazing, by templating from the frame

All drilling and notching happens before heat treatment, so locations are fixed at order. Site drilling and core drilling break tempered glass, and templating at glazing comes after the lite has already been made.GANA FB45-14 Recommended Applications for Heat-Treated Glass (2019)

A lite of insulating glass is slightly too large in the shop. What is correct?

• a.Order a new unit made to the right size✓
• b.Grind the edge in the shop until it fits
• c.Trim the spacer with snips to gain the room
• d.Nip the corner to relieve the tight fit

Finished insulating units should not be modified by cutting, seaming or grinding, so the remedy is a correctly sized unit. Grinding the edge alters a finished edge, trimming the spacer with snips damages the sealed airspace, and nipping the corner takes glass from a unit that cannot be reworked.Pilkington ATS-192 General glazing guidelines (2013)

Which glass edges are ground smooth in the shop?

• a.Edges that will be hidden inside the pocket
• b.No edges are ground, since factory edges are final
• c.Edges that will be exposed in finish work✓
• d.Only the edges of mirrors and similar lites

The guide specification calls for grinding smooth, in the shop, glass edges that will be exposed. Hidden edges and a mirrors-only rule are not stated.UFGS 08 81 00