On The Spot Firestop is a family-owned passive firestopping contractor in Denver founded in 2007. Its site states that it is a certified Qualified Firestop Contractor and it appears on the FCIA UL-qualified register. It is also certified MWBE, SBE and DBE by the City and County of Denver and the US Department of Transportation, and holds the Fireproofing Supervisor Licence the City requires for inspections. It works for Denver-area builders on complex commercial and multifamily projects.