Mr. Nelson joined Simpson Gumpertz & Heger Inc. (SGH) in 1975. He is the past head of SGH’s Building Technology group in the Boston office. He brings extensive experience to the team in evaluating, inspecting, analyzing, and repairing building-envelope systems. He specializes in evaluating moisture leakage, water vapor transmission, and condensation that may lead to mold, specifically for special-use buildings such as hospitals that have humidity-controlled interior environments. He is experienced in conducting field and laboratory investigations and evaluating materials, design and workmanship of roofing, waterproofing, windows, foundations, wall, and flooring systems.