What began in 1913 as a small manufacturer of pipe insulation has grown into the number one choice throughout the country for virtually all insulations and accessories from pipes to HVAC to roofing products. Headquartered in St. Paul, Minnesota, MacArthur Co.’s huge selection of best-in-class products and our strong dedication to customer service have helped us become the preferred reseller for contractors around the country—many of which have been our customers for multiple generations.