This invention relates to a method and system of applying a fluid material to a roofing surface. By modifying a peristaltic pump-driven sprayer device, a fluid material having a viscosity of 10,000 to 40,000 centipoise at 25° C. can be effectively sprayed onto a roofing surface. Additionally, the use of a modified peristaltic pump-driven sprayer device allows for the fluid material to be applied onto the roofing surface at a faster rate than other spraying methods.