Massachusetts Construction Supervisor License (CSL) Practice Test

What is the maximum number of layers of roof covering allowed on a single family dwelling?

1. 1 layer

2. 2 layers

3. 3 layers

4. 4 layers

The correct answer is: 2 layers

The maximum number of layers of roof covering allowed on a single-family dwelling is two layers. This regulation is in place primarily for safety and structural integrity reasons. Each additional layer of roofing adds weight to the structure, which can potentially compromise the building's ability to handle that weight, particularly during adverse weather conditions. In addition to weight concerns, multiple layers can also affect the roof's performance in terms of drainage and ventilation. When a homeowner or contractor applies a second layer of roof covering, it can help to extend the roof's lifespan without the need for a full replacement, but beyond two layers, the risks and potential for issues increase significantly. Overall, permitting only two layers of roofing helps to ensure that roofs remain safe and functional for their intended lifespan while minimizing the likelihood of future structural problems or premature failure. It underscores the importance of adhering to building codes and regulations that promote the safety and welfare of residential structures.