Marking Decades of Experience An independent, employee-owned third-party certification and testing agency with three divisions. BUILDING PRODUCTS works to certify manufacturers of structural and non-structural engineered wood products (like plywood, OSB, LVL, MDF, particleboard, rimboard) and structural adhesives; MANUFACTURED STRUCTURES does design and inspection of manufactured structures in more than 40 states; HEARTH PRODUCTS tests and certify solid-fuel and gas heating appliances. Based in Wisconsin, with laboratories in Wisconsin and Oregon, and clients in more than a dozen countries. PFS and TECO TESTED certification marks are MARKS YOU CAN BUILD ON!