The nozzle on the can is fitted by screwing on a straw or gun attachment. The can is shaken vigorously for 20 seconds and held upside down while pressure is applied to the trigger of the straw or gun. The stronger the pressure applied, the more forceful the output. On vertical surfaces, foam is always applied from the bottom upwards. During application, care is taken to ensure that the ambient and can temperature are within the range specified in the product TDS.