I want to know the answer to the following question:
What is the usual thickness of the mastic spread on roofs?
All the background I'm provided with is that "Mastic asphalt is heated to a temperature of 210 °C (410 °F) and is spread in layers to form an impervious barrier about 20 millimeters (0.79 inches) thick.". Is that enough to answer the question?
Answer: yes