Acoustical building panel, monolithic surface covering system incorporating an acoustical building panel, and methods of forming and installing the same

An acoustical building panel comprising:

• a fibrous panel comprising:
• a central portion having a first major surface;
• a perimeter portion circumscribing the central portion, the perimeter portion having a recess comprising a recess floor surface;
• a second major surface opposite the first major surface;
• and
• side edge surfaces that define a perimeter of the fibrous panel and extend from the second major surface to the recess floor surface;
• wherein the perimeter portion comprises the side edge surfaces, the perimeter portion having a first average density and the central portion having a second average density that is less than the first average density.

An acoustical building panel comprising:

• a body;
• and
• a scrim attached to the body;
• the acoustical building panel further comprising:
• a central portion having a first major surface;
• a perimeter portion circumscribing the central portion;
• a recess having a recess floor surface, the recess press-formed into at least a portion of the scrim present in the perimeter portion;
• a second major surface opposite the first major surface;
• and
• side edge surfaces that define a perimeter of the acoustical building panel and extend from the second major surface to the recess floor surface.