Interior Finishes and Doors/Windows
This domain tests drywall, finishes, ceilings, flooring, door and window installation, hardware, and egress. Questions often combine fire-rated assemblies, accessibility clearances, and weatherproofing.
Core rules and concepts
- Gypsum board thickness, type, and fastener schedule depend on the assembly. Fire-rated walls and ceilings require the specified board type, joints, and penetration protection. Type X is common in rated assemblies.
- Door frames, doors, and hardware must match the schedule and fire rating. Fire doors need labeled frames, closers, and positive latching. Egress doors must provide the required clear width and swing in the direction of egress where occupants are large.
- Windows and exterior doors need proper flashing, shims, and sealant integrated with the weather-resistive barrier. Head and sill flashing shed water outward.
- Interior finishes must meet code for flame spread and wet areas. Accessibility rules affect clear floor space, door hardware, and thresholds.
Worked example
A door schedule calls for a 20-minute fire-rated corridor door. The installer uses a standard hollow-core door in a labeled frame with no closer. The assembly fails because the door leaf, frame, and hardware must all be rated and self-closing. The rating applies to the complete assembly, not just the wall.
Traps that cost marks
Substituting a standard door in a rated opening; ignoring egress clear width; installing windows without sill flashing; using the wrong drywall type in a rated assembly; and missing blocking for hardware.
Key point: rated and egress openings require the complete assembly to comply.