A manually operated applicator for spraying and dispensing expanding foam chemicals from aerosol containers is provided. The applicator dispenses compressed gas in close proximity to the foam as the foam exits the applicator, which results in improved adhesion of the foam to surfaces. The applicator includes a nozzle, an aerosol inlet for connection to an aerosol container, a gas inlet for connection to a source of compressed gas, and a trigger for operation of the applicator. The nozzle includes outlets for dispensing the foam and the compressed gas.