Glazier screening questions: storefront, curtain wall, glass handling, sealants and state glazing licenses
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Glazier screening questions should find out which glazing work the candidate does (commercial storefront and curtain wall, residential windows and doors, shower enclosures and mirrors, or shop fabrication), then test the two things that cause the costliest failures: handling heavy glass safely, and installing systems that keep water out. A glazier who can set a lite but does not understand setting blocks, weeps and sealant compatibility will produce leaks and broken glass months after the job closes.
This page covers glaziers at commercial glazing contractors, residential window and door companies and glass shops. For the steel that supports curtain wall, see ironworker screening questions; for window installation done by carpenters, carpenter screening questions.
Which glazier
| Setting | Typical work | Ask the candidate |
|---|---|---|
| Commercial storefront and entrances | Aluminum frames, doors and hardware, glazing, sealants | "Which storefront systems have you installed?" |
| Curtain wall | Unitized or stick-built systems, anchors, hoisting units, high-rise work | "Unitized or stick-built, and how many floors up?" |
| Residential windows and doors | Replacement and new construction, flashing to the weather barrier | "How do you flash a new-construction window?" |
| Showers, mirrors and interior glass | Frameless enclosures, measuring, hardware, customer homes | "How do you measure for a frameless shower door?" |
| Glass shop and fabrication | Cutting, edging, insulating glass units, ordering | "Which machines have you run, and how do you check an order?" |
Licenses and apprenticeship
As of October 2026, not legal advice. Glazing licenses vary by state and city. We checked the Connecticut statute; confirm the rules for the job's location.
Connecticut includes flat glass work, defined as "installing, maintaining or repairing glass in residential or commercial structures," and automotive glass work among the occupations covered by its licensing chapter, overseen by an Automotive Glass Work and Flat Glass Work Board, and no one may perform the work of a licensed occupation without a license or a registration card from the Labor Department or the board (Conn. Gen. Stat. §§ 20-330 and 20-334). Many states do not license glaziers, and some cover glazing under a general or specialty contractor license held by the company. Ask the client what the work requires.
Many glaziers train through registered apprenticeships. Registered programs are approved by the Department of Labor or a State Apprenticeship Agency (Apprenticeship.gov), and employers can verify completion through Verify My Apprenticeship with the person's apprentice number and date of birth.
Knockout questions
| Question | What a strong answer sounds like | Red flags |
|---|---|---|
| Journeyworker or apprentice, and which program? | Names the program and completion date or current year. | Vague about training while claiming journey-level pay. |
| Do you hold the license the job requires [state, type]? | Yes, with number and expiry. | Unaware a license applies in that state. |
| Which aerial lifts, scaffolds or swing stages are you trained on? | Names the equipment and who trained them. | "I've used them, never trained." |
| The job is [location, height, travel, overtime]. Does that work? | Yes, or a clear limit. | Not comfortable with heights for curtain wall. |
Glass handling questions
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"How do you move and set a large lite of glass?"
- Strong answer: knows or calculates the weight, plans the route and crew size, uses vacuum lifters checked before each lift, A-frames or carts, cut-resistant gloves and sleeves, a glass manipulator or hoist when the weight calls for it, communicates throughout.
- Red flags: "Two of us just carry it."
-
"How do you tell tempered, laminated and annealed glass apart, and why does it matter?"
- Strong answer: checks the permanent label (bug) or order, knows tempered cannot be cut after tempering, laminated holds together when broken, and that safety glazing is required in certain locations under the building code.
- Red flags: plans to cut tempered glass on site.
-
"What do you check before you set an insulating glass unit?"
- Strong answer: size and type against the order, edge damage, setting blocks at the correct location and material, clearances, glazing pocket clean, weeps clear.
- Red flags: sets glass directly on the frame without blocks.
Installation and water questions
| Question | What a strong answer sounds like | Red flags |
|---|---|---|
| Talk me through installing a storefront. | Checks the opening for size, level and plumb, installs sill flashing or receptor where the system requires, anchors and shims per the shop drawings, sets frames, glazes with the system's method, seals perimeter joints with backer rod and sealant, water tests if specified. | Skips the sill, or caulks over the weeps. |
| How do you choose and apply sealant? | Uses the specified or manufacturer-approved sealant, checks compatibility with gaskets and the adjacent materials, cleans and primes as required, correct joint depth with backer rod. | "Whatever silicone is in the truck." |
| What does structural silicone glazing require? | Only by trained installers under the system's procedures, specified sealant, surface preparation, adhesion testing and documentation. | Has never done it but claims curtain wall experience. |
| A new window leaks at the head. How do you find out why? | Water tests in stages from the bottom up, checks flashing laps and weather barrier integration, sealant joints, glazing gaskets. | Adds more caulk on the outside. |
Measuring and drawings
- "How do you field measure for replacement glass?" Strong: daylight opening and glass size, pocket depth, glass type, tint and thickness, takes multiple measurements, notes out-of-square openings.
- "How do you read glazing shop drawings?" Strong: elevations, sections at sill, head and jamb, anchor details, glass schedule, sealant joints.
- "Have you hung doors and adjusted closers and hardware?" Strong: names hardware types, adjusts closers and pivots, fixes rubbing doors.
Residential and interior glass
Residential and shower glaziers work in customers' homes, often alone or in pairs, so add questions about care and communication.
- "How do you install a replacement window so it does not leak?" Strong: removes the old unit without damaging the weather barrier where possible, checks the rough opening, integrates a sill pan or flashing with the weather barrier so water sheds outward, shims and fastens per the manufacturer, insulates without bowing the frame, seals inside and out.
- "How do you protect the home while you work?" Strong: drop cloths, protects floors and furniture, cleans up every shard, and points out any existing damage to the customer first.
- "A frameless shower panel arrives a quarter inch short. What do you do?" Strong: rechecks the measurement, does not force it or improvise hardware, reorders and explains the delay to the customer.
Fall protection and site safety
Under OSHA's construction fall protection standard, employees on a walking or working surface with an unprotected side or edge 6 feet or more above a lower level must generally be protected by guardrails, safety nets or personal fall arrest systems (29 CFR 1926.501), and anyone working on a scaffold must be trained by a qualified person on that scaffold's hazards (29 CFR 1926.454). Ask: "How do you protect yourself and others when setting glass at an open floor edge?" and "How do you protect the area below when hoisting glass?" Strong answers include tie-off points, controlled access zones under the work and secured tools.
How glazier experience gets overstated
- Residential replacement presented as commercial curtain wall. Ask about anchors, stack joints and hoisting units.
- Helper time counted as glazing. Ask what they set themselves and the largest lite.
- Shower doors only for a storefront role, or the reverse. Both are skilled; they are different jobs.
- Sealant work without compatibility knowledge. Ask which sealant they used on their last project and why.
Scoring
Pass or fail
- Glazing setting and level match the order.
- Any required license held.
- Trained on the lifts and scaffolds the job uses, or can be before start.
- Describes safe glass handling and fall protection.
Scored 0 to 2 each (10 possible)
- Glass handling and identification.
- System installation and anchoring.
- Sealants, flashing and water management.
- Measuring and drawings.
- Doors, hardware or specialty work.
In the submittal, list glazing settings and systems installed, the tallest buildings worked on, license and apprenticeship, lift and scaffold training, and the candidate's storefront answer in their own words. For more on probing safety habits, see interview questions for safety mindset, and for the overall trade hiring process, the interview guide for skilled trades. Ask whether candidates can meet the job's lifting and height requirements, with or without accommodation, rather than about medical history.
Questions people ask
Do glaziers need a license?
In some states. As of October 2026, Connecticut's occupational licensing law covers flat glass work, defined as installing, maintaining or repairing glass in residential or commercial structures, and automotive glass work, and no one may perform licensed work there without a license or an apprentice registration. Many states do not license glaziers. Check the job's state and city; this is not legal advice.
What fall protection rules apply to glaziers?
Under OSHA's construction standard, employees on a walking or working surface with an unprotected side or edge 6 feet or more above a lower level must generally be protected by guardrails, safety nets or personal fall arrest systems (29 CFR 1926.501), and scaffold users must be trained by a qualified person (29 CFR 1926.454). Glaziers also work from aerial lifts and swing stages, so ask what they are trained on.
How do I verify a glazier apprenticeship?
For programs registered with the U.S. Department of Labor or a State Apprenticeship Agency, an employer can verify completion through Apprenticeship.gov's Verify My Apprenticeship tool with the person's apprentice number and date of birth. Union training centers can also confirm status.
What is the best question for a glazier phone screen?
Ask them to talk you through installing a storefront system from receiving the frames to the final seal: checking the opening, anchoring and shimming, setting blocks, glazing method, sealant joints and water testing. It shows whether they understand how the system keeps water out, not just how to lift glass.