C-17 Glazing exam questions, with answers
10 practice questions for the CSLB Glazing trade exam, each with the answer, a plain explanation and the source it rests on.
These are not real exam questions. CSLB does not release its test questions or answer keys, and nobody else has them. We write our own questions from the C-17 outline and the codes, standards and references CSLB lists for the exam. Each answer names its source so you can check it.
The C-17 exam has 5 sections. The questions below are grouped by section, with the share of the exam each one carries. Read the question, pick an answer, then open “Show the answer”. The other questions of the free test, scored section by section, are in the free 25-question C-17 test.
Planning and Estimating · 27% of the exam
Evaluating plans and specifications; performing job-related calculations.
1. You are checking the prescriptive window schedule for a new single-family home in Climate Zone 12 under the 2025 Energy Code. What is the maximum fenestration U-factor that Table 150.1-A requires in that climate zone?
- 0.27
- 0.30
- 0.35
- 0.40
Show the answer
Answer: A. The CEC's 2025 Single-Family Residential Compliance Manual states that Table 150.1-A sets a prescriptive maximum U-factor of 0.27 in Climate Zones 1 through 5, 11 through 14 and 16, and 0.30 in the others. The 0.40 value is the separate mandatory maximum of Section 150.0(q), so meeting it alone does not satisfy this schedule.
Source: CEC 2025 Single-Family Residential Compliance Manual, Chapter 3 (Table 150.1-A)
2. Before scheduling a two-person carry, you figure the weight of a fixed shower panel of 3/8-in tempered glass, 34 in x 78 in. The NGA weight table, as published by General Glass, lists 5/16 in = 4.0, 3/8 in = 5.0 and 1/2 in = 6.4 lb per sq ft. About how much does the panel weigh, to the nearest 0.1 lb?
- 73.7 lb
- 92.1 lb
- 93.3 lb
- 117.9 lb
Show the answer
Answer: B. Area is 34 x 78 / 144 = 18.42 sq ft, and 18.42 x 5.0 lb per sq ft is about 92.1 lb. The 73.7 lb and 117.9 lb answers use the rows for 5/16-in and 1/2-in glass. The 93.3 lb answer multiplies the perimeter in feet by 5.0 instead of the area.
Source: NGA approximate weight of architectural flat glass (General Glass International table)
Fabrication and Installation of Framing Systems · 21% of the exam
Measurements and calculations; fabrication of framing systems; installation of framing systems.
3. You are ordering the lites for a federal storefront project under UFGS 08 81 00, and the drawings show nominal opening sizes. How does the specification tell you to determine glass sizes that provide the required edge clearances?
- By subtracting the frame maker's standard catalog allowance
- By copying the sizes from the glass supplier's cutting list
- By measuring the actual opening that will receive the glass
- By scaling the opening size from the approved glazing drawings
Show the answer
Answer: C. UFGS 08 81 00 has you determine glass sizes that provide the required edge clearances by measuring the actual opening. Drawings, catalog allowances and supplier lists do not show how the frame was really built, so a lite ordered from them may lack clearance or bite.
Source: UFGS 08 81 00, Part 3, Preparation, UFGS 08 81 00 Glazing
4. You are forming a membrane sill pan in a wood-framed rough opening before setting a new window. According to Building Science Corporation Information Sheet 302, prepared for DOE Building America, what are the end dams at each side of the pan for?
- To stop water on the pan from moving sideways into the wall
- To stop water on the pan from draining toward the room
- To hold the window centered from side to side in the opening
- To carry the weight of the window down to the sill framing
Show the answer
Answer: A. Information Sheet 302 lists end dams as one of the four essentials of a pan flashing: they keep water from moving laterally into the wall. Stopping water from running toward the interior is the job of the back dam or a positive slope, and the end dams do not position or support the window.
Source: BSC Information Sheet 302, essential characteristics of pan flashing
Fabrication and Installation of Glazing Materials · 18% of the exam
Installation of glazing materials; specialty glazing installations; finish installation work.
5. On a federal project glazed under UFGS 08 81 00, an interior glass partition will have some glass edges left exposed in the finish work. How does the specification say to prepare those edges?
- Grind them smooth in the shop before delivery
- Grind them smooth on site after the glass is set
- Seal them with a bead of clear silicone on site
- Leave them as cut and add a metal trim cap on site
Show the answer
Answer: A. UFGS 08 81 00 has glass edges that will be exposed in finish work ground smooth in the shop. Doing it on site after setting risks chipping the set glass, and a bead of sealant or a trim cap does not meet the requirement for a ground edge.
Source: UFGS 08 81 00, Part 3, Preparation, UFGS 08 81 00 Glazing
6. A window perimeter gap on a job under UFGS 07 92 00 came out wider than the installation tolerance, and your installer wants to fill it with sealant at closeout. Does the specification allow it?
- Yes; the gap may be sealed once backer rod is set in it
- No; a preformed gasket has to close a gap of that width
- Yes; the gap may be sealed once both faces are primed
- No; sealant may not close gaps that exceed the tolerances
Show the answer
Answer: D. UFGS 07 92 00 says not to use sealants in place of flashing or drainage components, or to close gaps between walls and windows that exceed acceptable installation tolerances. Sealant used that way must be removed and the building enclosure problem corrected; backer rod or primer does not change the rule.
Source: UFGS 07 92 00, Part 3, Installation, UFGS 07 92 00 Joint Sealants
Glazing Replacement and Retrofit Projects · 15% of the exam
Glazing replacement projects; glazing retrofit projects.
7. Your crew has replaced windows inside a 1950 house under the EPA RRP rule and has taken up the plastic sheeting. Under 40 CFR 745.85(a)(5), what kind of vacuum must they use on the remaining surfaces and objects in the work area, including furniture and fixtures?
- A shop vacuum fitted with a fine-dust filter and bag
- A central vacuum that vents outside of the living area
- A vacuum with a HEPA filter as its last filtration stage
- A standard upright vacuum with a new disposable bag
Show the answer
Answer: C. 40 CFR 745.85(a)(5) requires a HEPA vacuum on the remaining surfaces and objects in an interior work area, and 40 CFR 745.83 defines it as having a HEPA filter as the last filtration stage, with no air leaking past it. Ordinary shop, central or upright vacuums do not meet that definition, however new the bag.
8. After you replace a bedroom window that serves as the emergency escape opening, the homeowner wants the old security bars put back over it. Under 2025 CRC R319.4.4, how must those bars work?
- Release from the outside with a fire department key only
- Release from the inside with no key, tool or extra force
- Open from the inside with a wrench stored at the window
- Open from the inside with a keyed padlock kept nearby
Show the answer
Answer: B. 2025 CRC R319.4.4 requires bars, grilles and similar devices over escape openings to be releasable or removable from the inside without a key, a tool or more force than the opening normally takes. A padlock or a stored wrench fails that test, and an exterior release for the fire department does not replace the inside release.
Safety · 19% of the exam
Worker safety; job site safety.
9. To reach a transom, your glazier sets up a single ladder with a working length of 16 ft between its foot and its top support. Under 8 CCR 3276, how far should the foot of the ladder be, horizontally, from the top support?
- 2 ft 8 in
- 3 ft 2 in
- 2 ft
- 4 ft
Show the answer
Answer: D. 8 CCR 3276(e)(9) calls for a pitch where the horizontal distance from the top support to the foot is one-quarter of the working length: 16 ft / 4 = 4 ft. The other answers come from dividing by 8, 6 or 5, which sets the ladder too steep and raises the chance that it tips backward.
10. Your crew is setting glass from the open perimeter of an upper floor of a building under construction. According to the Cal/OSHA Pocket Guide for the Construction Industry, citing 8 CCR 1670(a), at what fall distance is fall protection required for this work from the perimeter of a structure?
- 6 ft
- 7 1/2 ft
- 10 ft
- 15 ft
Show the answer
Answer: B. The Cal/OSHA Pocket Guide lists a fall distance of 7 1/2 ft or greater for work from the perimeter of a structure, citing 8 CCR 1670(a). The 15 ft figure in the guide is for other work, such as work on structural members and wood framing, and it does not apply to glaziers at a floor edge.
Where to go from here
How the license works, from experience to fees: how to get a C-17 license. Everything about the course: the C-17 exam page.
Questions from our free C-17 test, written from CSLB License Examination Study Guide, Glazing (C-17), form 13E-17 (03-2026), for examinations scheduled on or after April 1, 2023. CSLB notes that the percentages are approximate. Reviewed 14 October 2026. Study guidance only; we are not affiliated with CSLB or PSI.