Asphalt shingles have which of the following characteristics?

Asphalt shingles possess several key characteristics that are essential to understand in the context of fire safety and building materials.

Firstly, while they are not non-combustible, asphalt shingles do generally have some degree of fire resistance, classified based on their rating, such as Class A, B, or C, with Class A being the most fire-resistant. Each class indicates how well the material can withstand fire exposure, thereby providing some protection. However, it is critical to note that they can contribute to the problem during a fire due to their flammability.

Secondly, under fire conditions, asphalt shingles may start to drip and run. When exposed to high temperatures, the asphalt can melt and drip down from the roof, potentially igniting materials that it comes into contact with. This characteristic poses a risk as it can lead to further fire spread.

Thirdly, when burned, asphalt shingles produce heavy black smoke. This smoke is dense and filled with harmful gases, which can obscure visibility and pose a health hazard to both those involved in firefighting and nearby civilians.

Considering these points, the comprehensive nature of asphalt shingles during fire conditions substantiates the correct choice that sums up these characteristics simultaneously.