OCFA Vertical Ventilation Practice Exam

A 45° inspection cut is used to quickly assess the roof/attic area from the outside and identify factors that influence how you can ventilate safely and effectively. It looks for obstructions under the roof, such as foam insulation or a dropped ceiling, which can block airflow and affect where you place a vent. It also helps you see the orientation of the roof framing, which matters for understanding load paths, potential collapse points, and where voids or spaces exist for exhaust. Additionally, it can indicate whether the roof is conventional or lightweight construction, a key factor because lightweight roofs behave differently under fire loads and may collapse sooner, shaping your ventilation plan. Exterior wall color isn’t something the 45° cut reveals about the roof or attic conditions, so it isn’t identified by the inspection cut.