Technician Knowledge-Based Test (KBT)
Practice Questions & [Verified Answers],
Plus Explained Rationales|2026 Latest
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1. During installation of an aluminum storefront system, the primary
purpose of setting blocks beneath insulating glass units (IGUs) is
to:
A. Reduce solar heat gain through the glazing system.
B. Support the dead load of the glass and distribute weight properly
within the frame.
C. Increase the structural strength of the aluminum frame.
D. Eliminate the need for perimeter sealants.
Rationale: Setting blocks are load-bearing components placed at
specific quarter-point or engineered locations to support the weight
of the glass. They prevent direct glass-to-metal contact, promote
drainage, minimize edge stress, and help ensure proper load transfer
into the framing system. Improper placement can contribute to glass
breakage and seal failure.
2. Which glazing material is most resistant to impact and commonly
required in hazardous locations under building codes?
A. Annealed glass
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,B. Fully tempered safety glass
C. Wired glass
D. Float glass
Rationale: Fully tempered safety glass undergoes controlled heat
treatment that increases its strength several times over annealed
glass. When broken, it fractures into relatively small, less hazardous
pieces, making it suitable for doors, sidelites, and other hazardous
locations identified by code.
3. A curtain wall differs from a storefront primarily because a curtain
wall:
A. Is always constructed of steel.
B. Cannot contain insulated glass.
C. Is designed to span multiple floors and transfer wind loads to the
building structure.
D. Is installed only below grade.
Rationale: Curtain walls are engineered exterior wall systems
attached to the structural frame of a building. Unlike storefront
systems, which are generally limited to low-rise applications and carry
only their own weight, curtain walls accommodate greater structural
movement, wind pressures, and building deflection.
4. What is the primary function of thermal breaks in aluminum
framing systems?
A. Increase glass transparency.
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,B. Improve structural weldability.
C. Reduce conductive heat transfer through the frame.
D. Simplify field fabrication.
Rationale: Thermal breaks separate the interior and exterior
aluminum components using low-conductivity materials such as
polyamide. This significantly improves thermal performance, reduces
condensation, and enhances overall building energy efficiency.
5. Which tool provides the greatest accuracy when verifying that a
frame corner forms a true 90-degree angle?
A. Chalk line
B. Plumb bob
C. Framing square
D. Utility knife
Rationale: A framing square provides a reliable reference for checking
right angles during fabrication and installation. Accurate squareness
ensures proper glass fit, uniform sightlines, and smooth door
operation.
6. Silicone structural glazing differs from conventional glazing
because it:
A. Uses only mechanical fasteners.
B. Relies on structural silicone sealant to transfer wind loads between
glass and framing.
C. Eliminates the need for glass edge protection.
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, D. Requires annealed glass exclusively.
Rationale: Structural silicone glazing uses specially engineered silicone
sealants capable of carrying design loads while maintaining flexibility
under environmental movement. The system requires strict quality
control, compatible materials, and manufacturer-approved
procedures.
7. What is the greatest concern when handling large insulated glass
units using suction cups?
A. Glass discoloration.
B. Excessive UV exposure.
C. Verifying suction integrity before lifting.
D. Edge polishing.
Rationale: Suction cups must be inspected, cleaned, and tested before
every lift. Loss of vacuum can result in catastrophic dropping of heavy
glass panels, creating severe safety hazards and property damage.
8. Why are weep holes incorporated into storefront framing
systems?
A. Improve sound insulation.
B. Increase structural rigidity.
C. Prevent ultraviolet degradation.
D. Allow moisture to drain from glazing pockets.
Rationale: Weep systems permit water that enters pressure-equalized
glazing cavities to drain safely to the exterior. Blocked weep holes can
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