Main Features

Water based and easy to apply. Firestem Fire Resistant Sealant forms a flexible seal with good adhesion to most common building materials.

When subjected to heat Firestem Fire Resistant Sealant swells and chars to provide an inert barrier to smoke and flame. The fire resistance achievable with Firestem Fire Resistant Sealant depends upon the joint design, depth of sealant and substrates being sealed.


All surfaces to be sealed must be clean, dry and free from grease, laitence or dust.

When applying, ensure all crevices are filled and there is complete contact between sealant and substrate. Tool down using a wetted spatula. Any excess may be removed using soapy water before mastic dries.


Note: Depth of seal must not exceed width.

The formula for calculating the linear metres per cartridge is as follows:

Size of the Tube (310ml) / (Width of the Joint (mm) x Depth of the Joint (mm)) = Number of Linear Metres From A Tube



  • Fire rated for up to 4 hours
  • Non slumping rapid skinning
  • Flexible
  • Good adhesion to most substrates
  • Can be overpainted
  • For gaps up to 50mm
  • Great Acoustic Properties
  • High performance water based acrylic sealant.
  • Seals small voids and gaps around pipes, ducts, door/window frames and most internal floor and wall applications.
  • No mineral packing required to obtain performance.


Store in cool dry conditions. Use within 12 months.


Firestem Fire Resistant Sealant is tested by Warrington Exova to EN1366-3, EN1366-4 and BS476 part 20.

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