Expanded steel metal lath substrate for interior and exterior plaster, stucco, cementitious coatings, and stone reinforcement applications, including walls, ceilings, soffits, fascia, and ceramic tile underlayment. Manufactured to comply with ASTM C847 and ASTM A653, and suitable for installation in accordance with ASTM C1063 and applicable IBC requirements, including use as reinforcement for spray-applied fire-resistive materials.