Abstract: A reactive polyurethane mixture is applied by a high pressure airless spray applicator directly onto the primary backing of a moving substrate such as a carpet web. The applied reactive mixture is allowed to foam to an approximate predetermined thickness and density. While the blown or foamed backing layer still possesses substantial residual tackiness, it is compressed or regauged to a precise uniform thickness and simultaneously is provided with either an embossed or a smooth surface. The tack of internal cell walls of the blown backing layer retains the layer at the regauged thickness. Curing of the regauged backing layer by externally applied heat and/or by the heat of the exothermic reaction in the applied mixture is completed. Detackifying agents are applied to the regauging devices and/or to the applied backing layer to prevent adherence of the layer to the regauging devices. A surface skin formed of the detackifying agents is cured on the regauged backing layer.