About Us

Cavalier Corporation entered the radon industry in 1986 and soon became the northwest’s leading experts in radon testing and radon mitigation . Owners, Warren and Sylvia Riddle promptly availed themselves of all available radon training and credentials:

Environmental Protection Agency
National Radon Safety Board
National Environmental Health Association

Cavalier was one of the first companies in the nation to guarantee that every radon mitigation system they installed would achieve radon levels below the EPA recommended action level, 4 pCi/l. On average, Cavalier achieves reductions to about 1 pCi/l in existing structures. Cavalier has mitigated hundreds of existing structures including almost 300 structures at Fort Lewis, 16 structures at Mukogawa Fort Wright Institute, 9 structures at Gonzaga University, 3 banks, and hundreds of commercial buildings and homes.

When the Washington State Legislature enacted the Ventilation and Indoor Air Quality code in 1991, requiring radon systems in new housing, Cavalier had already been installing guaranteed systems in new homes for several years. Hundreds of builders have hired Cavalier to install guaranteed Cavalier radon systems in thousands of Spokane’s new homes.