Windows, Doors, Skylights and Sloped Glazing
This domain tests window and door installation, flashing and air sealing, hardware, skylight drainage and the safety rules for overhead glazing. Exam questions often present a rough opening, a water leak, or a sloped glazing detail and ask for the correct installation or code response.
Windows
- Operating types include casement, awning, slider, tilt-turn and fixed. Performance is rated under NAFS (AAMA/WDMA/CSA 101/I.S.2/A440) for design pressure, water penetration and air leakage.
- Installation requires level, plumb and square framing. Shim at the sill and jambs, not at the corners only. Use a continuous sill pan with a back dam, apply flashing tape in shingle fashion, air-seal from the interior and leave weep holes open.
- Avoid over-compressing insulation, which can distort frames and block drainage.
Doors
Entrance doors, frames and thresholds must be plumb and securely anchored. Door glass and sidelights require safety glazing, tempered or laminated as labelled. Panic hardware is required where code applies, and closers must be adjusted so the door latches without force. Weatherseal and threshold gaskets control air and water leakage.
Skylights and sloped glazing
- Provide slope for drainage, a condensation gutter, an insulated curb and shingle-lapped flashing.
- Overhead glazing must be laminated glass, or tempered glass with a protective screen where the code permits. Laminated glass retains fragments if breakage occurs.
- Design for snow load, thermal movement and ventilation; do not trap moisture in the curb assembly.
Worked example
A wood double-hung window is replaced with a vinyl slider in a 900 mm × 1200 mm rough opening. Confirm the rough opening is about 10 mm larger than the frame. Shim the sill at the third points and the jambs at lock and hinge locations. Check that the diagonals are equal; if the opening is out of square by more than about 3 mm, correct the framing before setting the window. Install a sill pan and flashing tape, apply low-expansion foam, and verify weep holes are clear.
Traps that cost marks
- Shimming only at corners, which bows the frame and cracks glass.
- Blocking weep holes with sealant or insulation.
- Omitting the sill pan or back dam.
- Using tempered glass overhead without the required protective screen where laminated glass is specified.
- Over-tightening screws on vinyl frames and distorting the operating sash.