Multilayer facer

A method of forming a multi-layer fiber mat comprising:

• pouring or discharging a first fluid mixture onto a porous belt or surface, the first fluid mixture comprising a first fluid and a first group of fibers that are homogenously mixed or dispersed within the first fluid;
• draining or removing the first fluid from the first fluid mixture as the first fluid mixture is poured or discharged onto the porous belt or surface in order to form a layer of the first group of fibers atop the porous belt or surface;
• pouring or discharging a second fluid mixture onto the porous belt or surface atop the layer of the first group of fibers as the first fluid is drained or removed from the first fluid mixture, the second fluid mixture comprising a second fluid and a second group of fibers that are homogenously mixed or dispersed within the second fluid;
• draining or removing the second fluid from the second fluid mixture as the second fluid mixture is poured or discharged onto the porous belt or surface in order to form a layer of the second group of fibers atop the porous belt or surface and atop the layer of the first group of fibers;
• applying a binder to the layer of the first group of fibers and the layer of the second group of fibers in order to simultaneously bind the layer of the first group of fibers and the layer of the second group of fibers together and bind the first group of fibers and the second group of fibers together;
• and
• applying a coating atop the layer of the second group of fibers, wherein the coating is applied simultaneously with the binder or immediately after the application of the binder;
• wherein the second fluid mixture is poured or discharged into the hydroformer in direct fluid contact with the first fluid mixture such that the layer of the first group of fibers is formed atop the porous belt or surface at the same time the layer of the second group of fibers is formed atop the first group of fibers.