Firestem Intumescent Mastic
Product Description
High performance acrylic based construction sealant for sealing joints and cracks in fire rated internal walls and floors. In the event of fire Firestem™ Intumescent Mastic provides a barrier to flame and smoke preventing the spread of the fire and toxic gases through building joints. 4 hour fire rating on brick, concrete, steel and vermiculite with a single 12.5mm deep seal.
Water based and easy to apply. Firestem™ Intumescent Mastic forms a flexible seal with good adhesion to most common building materials.
When subjected to heat Firestem™ Intumescent Mastic swells (intumesces) to provide an inert barrier to smoke and flame. The fire resistance achievable with Firestem™ Intumescent Mastic depends upon the joint design, depth of sealant and substrates being sealed.
Certification
Firestem™ Intumescent Mastic is tested by Warrington Fire Research Consultants to BS476 part 20 and achieves 4 hours Fire Resistance
Application
- All surfaces to be sealed must be clean, dry and free from grease, latience or dust
- Apply mastic over a polyethylene backing rod to a minimum depth of 12.5mm
- Whenn 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 fomula for calculating the linear metres per cartridge is as follows:
310 ÷ gap width (mm) x gap depth (mm)
Technical Information
Product LiteratureCurrently Unavailable