Michigan Residential Builders License Practice Test

The longer the pitch of a roof, the ______ the rafter must be.

1. shorter

2. thicker

3. longer

4. weaker

The correct answer is: longer

The correct choice is that the longer the pitch of a roof, the rafter must be longer. This is because the pitch of a roof is defined by the angle at which the roof slopes. A steeper pitch requires the rafters to extend further from the ridge (the peak of the roof) down to the wall plates, which support the rafters. As the pitch increases, the vertical rise is greater for a given horizontal span, which necessitates longer rafters to adequately reach from the ridge to the walls while maintaining the desired angle of the roof. Consequently, this relationship between roof pitch and rafter length is critical in structural design, ensuring that the roof maintains its integrity and function under various weather conditions.