Chapter 4 of 515% of exam

Glazing Replacement and Retrofit Projects

CSLB weights Glazing Replacement and Retrofit Projects at about 15% of the C-17 exam: replacing glass in existing openings and retrofitting existing glazing. This page is a short survey; the PrepPass C-17 Glazing study guide teaches the section with worked examples and a full practice exam at CSLB's weights.

Replace to the new-work rules

Replacement glass is installed as required for new installations, so hazardous locations get identified safety glazing.

New-work rule
The installation of replacement glass is as required for new installations.
2025 CBC §2402.1
Why it broke
Partial shading, signs on the glass, chipped edges and ponded pockets are common causes in the glass makers' guidelines.
Pilkington ATS-192

Order from the opening

Measure the actual opening, never plan to trim finished glass, and order an insulating unit by overall thickness.

Overall thickness
Overall thickness runs outside surface to outside surface; gap width runs inside to inside.
CEC residential compliance manual Ch. 3
Lead renovation
Removing windows from pre-1978 housing can require an EPA-certified firm.
40 CFR 745

Retrofit for energy and safety

Check the pocket depth and the frame's capacity for heavier glass; use NFRC labels or default values; a door with 25 percent glass or more is fenestration.

Labels
Windows that are not field-fabricated carry NFRC-certified or default labels.
CEC residential compliance manual Ch. 3
Window fall protection
Low sills high above grade need a 4-inch-sphere opening limit or a control device.
2025 CRC §R321.2

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