TBA Tube 4hr Fire-Rated Acrylic Mastic

Firefly lntumastic is a water based acrylic sealant, which is available in either white or grey. It can be over-painted with oil or water based paints. For small linear gap seals, we recommend the use of polythene backing rods to ensure maximum economy in use and to form the correct profile to the seal to allow movement without forcing the seal out of the gap.


  • Provides flexible seals to joints up to 25 mm
  • Joint movement capability of +/-10%
  • Applied against a polythene backing rod to a width to depth ratio of 1:1
  • For use in Concrete floors, Plasterboard, Speedpanel, Powerscape, Block walls and TBA Intubatt
  • Tested in both vertical and horizontal applications