ナイガイ株式会社 designs and installs Thermotex and Thermotex SW sprayed rockwool steel fireproofing alongside its core thermal insulation and duct fabrication business. It is named on the Rock Wool Association’s register as a holder of individual 国土交通大臣認定 耐火構造 (FP) approvals for 吹付けロックウール被覆, and Thermotex is separately approved as a 不燃材料. The firm works from 28 offices between Hokkaido and Okinawa.