Building Exteriors & Roofing Systems. How has your building’s exterior fared under the stress of time and weather? Even the most solidly constructed surfaces suffer cracks, loosening, or decay. To protect and preserve the treasure inside, each building requires maintenance and occasional repair, and even replacement, to reverse the damage of wear and tear. Commercial building owners trust Simpson of Maryland to prevent potential problems and fix the unexpected ones. Our business has thrived because we attract top-notch talent - and every member of our team values quality, service and safety. Whether your project is large or small in scope and size, we promise to deliver the very best service in the industry. Call us today and discover why we’re the premier choice in Commercial Roofing, Sheet Metal, Masonry Restoration and Waterproofing. Simpson of Maryland proudly serves the greater Maryland, Washington, D.C. and Northern Virginia regions.