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Take coverage and performance to the max.

Even the best product on the market can be improved. That’s why we’ve updated the premier intumescent Firestop Sealant FS-ONE to Hilti Firestop Sealant FS-ONE MAX. With an extended shelf life, improved handling and an ethylene glycol-free composition, FS-ONE MAX is the next generation of intumescent firestop sealant.

FS-ONE MAX directly replaces Hilti Firestop Selant FS-ONE. In addition, all of our UL systems have been updated to reflect the new, improved FS-ONE MAX. That means you’ll now find more than 600 UL systems to help protect combustible and non-combustible penetrations for up to 4 hours of fire rating.

fs-one max applications


  • Seal most common through penetrations in a variety of base materials
  • Use on concrete, masonry and drywall
  • Use with mixed and multiple penetrations
  • Seal metal pipe penetrations: copper, steel and EMT
  • Seal insulated metal pipe penetrations: steel and copper
fs-one max advantages


  • Versatile: an intumescent firestop sealant for a wide variety of penetrations
  • Effective: smoke, gas and water resistant
  • Workable: water-based material is easy to dispense and apply
  • Paintable: trowel to a smooth finish
  • Storable: long shelf life
  • Cleaner: ethylene glycol-free
  • Flexible: W-rated systems available
  • American: satisfies Buy American standards

Easily substitute - and upgrade

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Testing in ongoing

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Upgrade your specification text to include FS-ONE MAX

Download the relevant specification sections