There are several types of roof waterproofing, including:

Built-up Roofing (BUR): This is a traditional roofing system that involves layering asphalt or coal-tar saturated felt and bitumen to create a waterproof membrane.

Modified Bitumen: This is a modern roofing system that involves modified asphalt to create a waterproof membrane. It can be installed in single or multi-ply layers.

Single-ply Membrane: This is a popular roofing system that involves a single layer of synthetic material, such as PVC or TPO, to create a waterproof membrane.

Spray Polyurethane Foam (SPF): This roofing system involves spraying a layer of foam insulation onto the roof surface and then coating it with a waterproof membrane.

Liquid-applied Membrane: This is a roofing system that involves applying a liquid coating, such as silicone or acrylic, onto the roof surface to create a waterproof membrane.

Metal Roof Coating: This is a roofing system that involves coating a metal roof with a waterproof membrane, such as acrylic or silicone.

The choice of roofing system depends on various factors, including the type of roof, the building's location, and the budget. Each type of roofing system has its advantages and disadvantages, and it is important to consult with a professional roofing contractor to determine the best option for your specific needs.