THERM-O-ROCK WEST, INC. The Southwest’s Largest Producer of Expanded Perlite and Vermiculite Products Since 1981 Our Products Help turn This... Into This... Or This... Therm-O-Rock West’s facility is situated on 10 acres in Chandler, Arizona, 20 miles south of Phoenix. Located next to major highways and with its own rail siding, we are able to provide excellent service to customers throughout the Western United States, Canada and many overseas locations. As a major supplier to well known companies in horticulture, construction and various other industries, we are committed to the highest standard of quality and service. Perlite-Vermiculite THERM-O-ROCK WEST, INC.