North Carolina Home Inspector Practice Exam

In a house with two layers of shingles, where is leakage most likely to occur?

1. On the roof slope

2. Around the chimney

3. In the valley

4. At the eaves

The correct answer is: In the valley

In a house with two layers of shingles, the likelihood of leakage is heightened in the valley due to the unique way that water flows and accumulates in these areas. Valleys are the places where two slopes meet and channel water down towards the eaves. If there are defects or weaknesses in the shingle layers, such as improper installation, wear, or degradation, this can lead to water infiltration. The design of valleys can often trap debris and prevent proper drainage, exacerbating the potential for leaks, especially when heavy rain occurs. While water can leak from other parts of the roof, such as the roof slope, areas around the chimney, or at the eaves, these tend to be more straightforward drainage points compared to valleys. The complex geometry and water accumulation in valleys make them particularly susceptible to leakage when there are underlying issues with the roofing materials.