Abstract: A nozzle for the injection of urea-formaldehyde foam insulation in a building includes a two-stage foaming chamber in the foam chemical line which includes a plurality of jets for effecting bubbling of the foaming chemical and a bubble-sizing, apertured plate positioned downstream of the jets to further enhance the foaming action of the chamber. The nozzle further includes a body into which the foaming agent is coaxially delivered with respect to an axailly extending resin injector. The end of the resin injector extends from the body of the nozzle and a flexible injection hose is removably attached to the end of the nozzle such that the resin and foaming agent mix in the flexible hose.