40 Hour Property and Building Inspection Practice Test

What type of damming can skylights cause on roofs?

1. Snow

2. Wind

3. Ice

4. Water

The correct answer is: Ice

Skylights can indeed lead to ice damming on roofs, particularly in colder climates or during winter months. When the snow accumulates on the roof, heat from the building can cause the snow near the skylight to melt. This melted snow flows down the roof toward the eaves, where it meets colder air and refreezes. Consequently, ice builds up at that point, forming an ice dam. This situation can be exacerbated by the fact that skylights often have different thermal properties compared to the surrounding roof area, leading to uneven melting and contributing to the formation of ice dams. Such ice buildup can create significant problems, including potential water infiltration under shingles, which can cause leaks and damage to the roof structure over time. Understanding this process is crucial for property and building inspectors as it highlights the importance of proper insulation and ventilation in roofing systems, particularly around features like skylights.