Doors, Windows, and Finishes
Doors, frames, and hardware
A fire-rated opening is an assembly: door, frame, and hardware all carry the label, and NFPA 80 governs installation and periodic inspection. Typical ratings are 20, 45, 60, and 90 minutes; a 90-minute door in a 2-hour wall is normal. Egress requires about 32 in clear width for a 3 ft 0 in door in a standard frame, hardware operable with one hand and no key or special knowledge, and panic hardware where the occupant load requires it. Accessibility: maximum 5 lbf interior opening force, 1/2 in maximum threshold, operable parts no higher than 48 in and typically 34 in above finish floor for repeated-use controls.
Windows and glazing
Energy performance is published as U-value and SHGC on an NFRC label. Safety glazing under CPSC 16 CFR 1201 is required in hazardous locations: glazing in and adjacent to doors, large low panels, tub and shower enclosures, and along stairs. Know storefront versus curtain wall and the air, water, and structural mock-up tests.
Finishes
Gypsum board finish levels 1 through 5 per GA-214: Level 4 is standard for paint; Level 5 is required for gloss, critical lighting, and dark colors. Type X board is used in rated assemblies, but the entire UL assembly (stud size, spacing, layers, fastener type and spacing) must match. Tile needs proper substrate and movement joints; resilient flooring needs flatness and moisture testing; acoustical ceilings need hanger wire and seismic bracing where required.
Worked example
A 3 ft 0 in x 7 ft 0 in door in a 2 in face frame with 4-1/2 in stiles yields roughly 32-34 in clear opening. If an answer choice says 36 in clear, it is wrong - clear width is measured at the narrowest point, usually the hinge stile.
Traps: substituting one component of a rated assembly, or confusing door rating with wall rating.