Nano Narrative on Instagram: "The video shows the application of pour-and-roll bitumen, a traditional and highly effective method for waterproofing flat roofs. The Material: Hot liquid bitumen (asphalt) is poured from a bucket onto the roof surface. It is heated to a high temperature, hence the steam seen in the video. The Technique: A roofer unrolls a reinforced felt membrane directly into the hot puddle. The weight of the roll and the liquid state of the bitumen ensure a complete, airtight bon