Roof waterproofing with tar is a traditional method, often called "built-up roofing." It involves layering roofing felt or fiberglass mats with hot-applied or cold-applied bitumen (tar) to create a waterproof membrane. This method can be effective but has some disadvantages like its heavy weight and the potential for fumes during installation. Modern alternatives like single-ply membranes or modified bitumen roofing are often preferred for their ease of installation and performance. | KSSE Struc