Humber/Ontario Real Estate Course 4 Exam 2025 – 400 Free Practice Questions to Pass the Exam

A roof sagging between trusses is likely due to the presence of undersized trusses. When trusses are not appropriately designed or are too small to support the weight of the roof and any additional loads (such as snow, ice, or equipment), they can bow or sag under pressure. This structural failure often leads to visible sagging in the roof line, indicating that the trusses are insufficient for the load requirements.

Thin sheathing might contribute to a lack of overall roof strength, but it is not the primary cause of sagging; rather, it could exacerbate other structural issues. Inadequate flashing deals with water control and may lead to leaks, not sagging. Condensation in the attic and improper ventilation can lead to moisture problems, affecting the roof's integrity over time but not directly causing immediate sagging. Poor insulation might improve energy efficiency but does not influence the structural capacity of the trusses themselves. Therefore, the issue of poorly sized trusses is the most direct cause of sagging in this scenario.