Cornerstone Building Brands, a manufacturer of exterior building products, completed the acquisition of MAC Metal Architectural, a manufacturer of steel sidings and roofing products. Financial terms were not disclosed. “The acquisition of MAC Metal Architectural expands our leading exteriors portfolio with value-added, residential-focused metal siding and roofing products that offer premium aesthetic design and durability solutions for our customers. This business increases our exposure to a fast-growing product segment that also leverages our existing manufacturing expertise," Rose Lee, Cornerstone Building Brands President and CEO.