Cut Sheet

2
Technical Service 1-800-992-1180
www.stifirestop.com
SpecSeal® Series SIL Silicone Firestop Sealant is approved
for a variety of through-penetration firestop systems and
joint applications. Some typical installations have been
illustrated here to assist in the selection of the proper
installation method. Space limitations preclude highly detailed
information pertaining to individual application systems.
Please consult the STI Product and Application Guide, as well
as the UL Fire Resistance Directory for additional information.
Preparation: All surfaces to receive SpecSeal® Series SIL
Silicone Firestop Sealant must be clean, sound, dry, frost-free,
and free of bond-breaking contaminants and loose material.
Clean as necessary by wire brush, mechanical abrading,
grinding, blast cleaning, or wiping with a suitable solvent to
remove any contaminants. Mask all areas where adhesion is
undesirable. Do not apply to wet or frost covered surfaces.
Forming: Some installations may require forming as either
an integral part of the system or as an option to facilitate
installation. In systems where forming is required, mineral
wool batt insulation (minimum 4 lb./cu. ft. or 64 kg/m3 density)
is recommended for use in through-penetrations and joints.
Where forming materials are required, cut oversized to allow
for tight packing. Some individual joint systems may specify
a minimum compression factor to allow designed amount
of movement. Position forming material as required for the
proper depth of fill material.
Fill Material: SpecSeal® Series SIL300 Silicone Firestop Sealant may be installed by caulking using a standard caulking gun or from bulk containers using a bulk loading caulk
gun, or by manually troweling using a mason’s trowel or putty knife. SIL300SL may be installed by pouring the sealant into the opening and allowing it to find level. If the sealant
tends to pull back from a surface, clean the surfaces using the methods described above and reapply. Install sealant to required depth. For SIL300, work sealant into all areas
with a tooling knife exercising care to eliminate voids or seams. In gypsum wall board penetrations, crown sealant a minimum of 1/4" (7 mm) from penetrant to wallboard surface
at a point approx. 1/2" (13 mm) or more from opening. For applications involving cable bundles, spread cables sufficiently to ensure that sealant completely seals all cables and
totally fills all voids to the required depth. Exercise care when using SIL300SL that packing material has been installed tightly into opening to prevent leakage of fill material.
Priming: SpecSeal® Series SIL Silicone Firestop Sealants have primerless adhesion to many construction materials including untreated or uncoated concrete. Jobsite trial
applications are recommended if contact surfaces are in any way questionable. Application of a suitable primer may remedy adhesion difficulties for questionable concrete
surfaces. Contact the factory for primer recommendations.
Masking: The use of masking tape is recommended where appropriate to insure a neat job and to protect adjoining surfaces. Do not allow masking tape to touch clean surfaces
to which the silicone sealant is to adhere. Masking tape should be removed immediately after the finish tooling of the SpecSeal® Series SIL Silicone Firestop Sealant.
Smoke Sealing: SpecSeal® Series SIL Silicone Firestop Sealants make an excellent smoke seal. Apply to gaps and seams to prevent the passage of smoke. Some SpecSeal
Firestop Collar designs utilize SpecSeal® Series SIL Silicone Firestop Sealants as the smoke seal. Please consult the STI Product and Application Guide, as well as the UL
Fire Resistance Directory for additional information.
INSTALLATION INSTRUCTIONS
STI Product Data Sheet •SpecSeal® Series SIL Silicone Firestop Sealant • FOD-5112 1586
Fig. 2: MISCELLANEOUS METALLIC PIPE PENETRATIONS
UL SYSTEM W-L-1033
F Rating: 2 hr • T Rating: 0 hr
Steel Pipe: 6", Copper Pipe or Tubing: 4"
Sealant Depth: 1/4" (within annulus) + 1/4" Crown
Forming Material: Nom 4 pcf Mineral Wool
Tightly Packed to a 1" Depth.
UL SYSTEM C-AJ-1198
F Rating: 3 hr • T Rating: 0 hr
Steel or Iron Pipe: 24", Copper Pipe: 6"
Annulus: Point Contact to 2 1/4" • Sealant Depth: 1/2"
Forming Material: Nom 4 pcf Mineral Wool
Tightly Packed to a 4" Depth.
Fig. 1: HEAD OF WALL
UL SYSTEM HW-D-0312
Assembly Ratings - 2 and 3 Hr
Nominal Joint Width - 1 in.
Class II Movement Capabilities - 12.5% Compression or Extension
L Rating At Ambient - Less Than 1 CFM/Lin Ft.
L Rating At 400º F - Less Than 1 CFM/Lin Ft.