Make any necessary ceiling repairs before applying. Sprays best between 70 and 80 degrees Fahrenheit. SHAKE CAN vigorously for one full minute AFTER ball starts to rattle (Shaking continuously during use is also recommended). Carefully insert straw into nozzle, and spray a short burst on test cardboard/material to prepare nozzle. This is a VERTICAL Spray, so hold can VERTICALLY approximately 18" to 24" from ceiling.