North Carolina Building Contractor License Practice Exam

For roof slopes of 4 units in 12 units horizontal, what type of underlayment is required?

1. 1 layer of felt

2. Ice barrier for roofing underlayment

3. Granular roofing paper

4. Modified bitumen sheet

The correct answer is: Ice barrier for roofing underlayment

In North Carolina, underlayment requirements for roofing systems depend on the slope of the roof and specific local building codes. For roofs with a slope of 4 units in 12 units horizontal, it is typically required to install an ice barrier as part of the roofing underlayment. An ice barrier is particularly crucial for areas that experience freeze-thaw cycles; it helps prevent water infiltration that can result from melting ice or snow. This barrier is installed at the eaves and in areas most susceptible to ice dams, which can cause significant damage if not properly managed. In the case of this roof slope, the installation of an ice barrier is a preventive measure to ensure water does not seep under the roofing materials and leads to leaks or structural damage. Thus, the inclusion of this specific type of underlayment caters to both building code requirements and the practical considerations of weather-resistant roofing systems.