STI Firestop SpecSeal SIL300 Silicone Sealant – Self Leveling

Call for Price

  • Ozone and UV Resistant
  • Excellent recovery from joint extension and compression
  • Listed in over 175 UL Tested Systems!
  • UL® GreenGuard Gold Certified

SKU: N/A Category: Tag:

SpecSeal SIL300 Silicone Sealant is a high performance silicone firestop sealant tested to resist the passage of smoke, flame and water through construction joints and through-penetrations. SIL300 Sealant cures to form a flexible seal and carries a Class 1 W Rating for water resistance (Per ANSI/UL1479).

Physical Properties

As Supplied

PropertySIL300SL (Self-Leveling)
Density/(Weight per Gallon)11.5 lbs/gal
CoverageFor more information on product coverage see the following documents for Linear Joint & Penetration
Viscosity25,000 cps
Storage TemperatureLess than 80°F (27°C)
Application Temperature35°F (-37°C) to 140°F (60°C)
VOC ContentLess than 47 g/L*
Shelf Life From Date of Manufacture18 months
Tooling Time25 to 30 minutes
Tack Free, ASTM C679 (77°F, 50%RH)50 to 60 minutes
Sag/Slump, ASTM D2202N/A
Storage Warranty Period12 months from date of shipment if stored in original unopened container at 80°F (27°C)


PropertySIL300SL (Self-Leveling)
Flame Spread5**
Smoke Developed45**
Mold & Fungus Growth Rating (ASTM G21)1
Movement Capabilities± 50% (ASTM C719), ± 15% (ASTM E1399)
In Service Temperature-35°F (-37°C) to 300°F (149°C)
Shore A Hardness (ASTM D2240)26
STC Rating (Relates to Specific Construction), (ASTM E 90-04/ASTM C919)61
Weathering & U.V. ResistanceExcellent
Tensile Strength, psi (ASTM D412)110 psi (0.76 MPa)
Elongation % (ASTM D412)600%
Tensile at 100% Elongation (ASTM D412)60 psi (0.41 MPa)
Peel Strength (21 day cure @ 77ºF/50 RH), ASTM C79412 pli

*Per SCAQMD Rule 1168 (EPA Method 24)

**Tested to ASTM E84 (UL723) at 14% surface coverage (modified test for sealants and caulks)


STI Firestop


10.3 oz. Tube, 20 oz. Sausage, 4.5 Gallon Pail

© 2021 Cable and Connections Acquisition Company LLC. | 888-WIRE-682 (888-947-3682)