ST. LOUIS — McGrath & Associates is building a new $5 million warehouse for U.S. Paint, a developer and manufacturer of customized automotive and industrial paints, at the company’s facility in downtown St. Louis. McGrath will work in two phases to replace an existing warehouse with a 33,000-square-foot building while the manufacturing facility remains operational. During Phase I, McGrath will erect a new pre-engineered metal building to provide new office space, a maintenance shop, a battery charging area and storage for raw materials. A connecting link will tie the new building into an existing manufacturing building to allow covered access for forklift truck traffic. During Phase II, the existing raw materials warehouse will be demolished and a new building erected to provide space for a quality control lab and liquid materials storage. Japan-based Kansai Paint acquired U.S. Paint last year.