DEI provided structural engineering services for Shea Concrete regarding the roof structure for the Shea warehouse in Amesbury, MA. The existing lightweight timber framed pitched roof placed over a flat roof had been damaged from a winter storm, and had shown signs of timber decay. As a result, the owner decided to replace the roof. Various design issues were seen to be present at the site, including unreinforced masonry walls, and a taller batch plant structure directly adjacent to the roof creating a large snow drift possibility. DEI came up with a solution consisting of new structural steel bar joists, metal decking, rigid insulation, and a rubber roof membrane, all of which to replace the existing roof structure. The new bar joists were designed to bear on retrofitted concrete caps on top of the existing CMU walls and existing steel girders, with a higher concentration of joists in the possible drift zones.