Interior Finishes, Doors, and Windows
Finishes
Understand drywall levels of finish (Level 1 through 5), gypsum board types (regular, Type X, moisture-resistant, abuse-resistant), and the sequence of taping, sanding, and priming. Know ceiling systems (acoustical tile, grid), flooring types (hardwood, tile, carpet, resilient), and substrate requirements. Traps: confusing fire-rated Type X with moisture-resistant board, and specifying Level 5 where Level 4 is standard.
Doors and frames
Study hollow metal versus wood doors, fire ratings (20, 45, 60, 90 minute), and the requirement that fire-rated doors self-close and latch. Know frame types (knock-down, welded), hardware sets, and the Americans with Disabilities Act clear width (32 in minimum clear). Traps: forgetting that a pair of doors needs an astragal and coordinator, and mismatching hardware to door rating.
Windows and glazing
Understand window types (fixed, casement, double-hung), U-factor and SHGC, and the difference between tempered and laminated glass. Tempered glass is required in hazardous locations such as doors and low windows. Know that NFRC ratings compare performance.
Worked example
A 36 in door in a 4-7/8 in frame gives roughly 33 in clear width, which meets the 32 in minimum. A 32 in door yields about 29 in clear and fails.
Rule of thumb
Fire-rated doors must self-close and latch; hardware must match the rating, not just the look.