O.S. Interior Systems incorporated in 1972 and has been successfully doing business as a commercial interior contractor ever ... since. Through the years, we have been able to adapt to changing economic tides largely because of our dedication to safety, low overhead and the ability of our key employees to adjust to changing workflows. Over the years and still today, our company performs as a very competitive subcontractor in the multiple roles of Gypsum Board Systems, Relocatable Partitions, Acoustical Ceilings as well as all types of Architectural Finishes. We are among the largest specialty contractors in Texas and the largest installers of the Gravity Lock Wall System in the USA. read more