Which roofing material is typically installed on flat roofs?

Hot mopped tar is commonly used on flat roofs due to its effective waterproofing properties and ability to create a monolithic barrier against moisture. This roofing technique involves applying layers of tar to the roofing substrate, which helps to ensure a watertight seal that is necessary for flat roofs typically prone to water pooling.

Flat roofs require materials that can withstand standing water and resist water penetration, and hot mopped tar meets these criteria effectively. It adheres well to various substrates and can accommodate the slight movement and settling that may occur in flat roof structures, reducing the risk of leaks over time.

Other materials, such as asphalt shingles, are generally not suitable for flat roofs due to their design, which is more effective on sloped surfaces. Similarly, slate tiles and metal roofing are also tailored for pitched applications and would not perform well in flat roofing contexts.