Final answer:
Roofs with several layers of composition shingles or other roof coverings typically hinder ventilation efforts, can mask structural issues, and are not indicative of structural stability.
Step-by-step explanation:
Rooftops with multiple layers of composition shingles or other coverings tend to hinder ventilation efforts rather than facilitate them. While traditional building techniques varied depending on climate and available materials, the addition of extra layers on a roof can trap heat and moisture, leading to decreased airflow. For instance, traditional adobe houses had nearly flat roofs suitable for dry climates, allowing for rainwater or dew collection. In contrast, steeply pitched roofs were utilized in regions with harsh winters to manage snow load and conserve warmth.
In regions where snowfall is significant, a sharply pitched roof like that of a long house allows snow to fall to the ground without causing collapse. The layering of roofing materials typically does not demand specialized tools, but it can mask issues related to structural stability. Excessive layering can be a sign of deferred maintenance or an attempt to address leaks without correcting underlying structural concerns.