Asphalt roll roofing is a material commonly used on flat / low sloped roofs. The material used is similar to asphalt shingles using an organic felt / fibreglass mat saturated with asphalt and stone aggregate on top.
As its name suggests, it comes in rolls and is installed starting at the eaves working your way up to the ridge. Each row that is rolled out overlaps the row below it, just as you would with asphalt shingles. It can be installed by gluing (or nailing) it in place, using hot bitumen or torched & pressed on. Since, the seams overlap they must be sealed to prevent water from getting in or the wind from lifting it up. Similarly, any roof penetrations / protrusions must be sealed.
Troubles occur however when with seams are not sealed or glued down, air bubbles get underneath the roll roofing, or the material is not lying flat on the roof. As with asphalt shingles, roll roofing material can crack or the stone granular can wear off. Its life span is considerably less than asphalt shingles however (perhaps 5 to 10 years) as it exposed longer to water, snow, ice, etc.
In the picture shown here there are two readily apparent problems: (1) a drip edge was installed over the roll roofing at the roof’s edge blocking water from evacuating off of it, and (2) the layers of the roll roofing were not sealed (potential for water moisture penetration into the building). In winter, ice damming would wreak havoc with this roof allowing water into the building.