Product Description

TREMstop® Fyre-Sil is a gun-grade, neutral-cure silicone sealant designed for use in firestop applications, including both joints and through-penetrations.

Basic Uses

TREMstop Fyre-Sil is for use on metal pipe, plastic pipe, cables, cable trays, ducts and multiple through-penetrations as well as static joints and dynamic joints in concrete, wood floor/ceiling and gypsum wall assemblies and perimeter fire barrier joints.

Features and Benefits

TREMstop Fyre-Sil is a firestop product that also provides protection against washout conditions. When installed in accordance with a tested firestop system, it affords code compliance for both through-penetrations and fire-rated joints.

Applicable Standards

UL1479 (ASTM E 814), UL 723 (ASTM E 84), UL 2079 (ASTM E 1966), ASTM E 1399, CAN4-S115M


10.1 oz. (300mL) cartridge, 20 oz. (600mL) sausage, 28.7 oz. (850mL) cartridge, 5 gal. (19L) pail


Rust Red, Limestone. 

Surface Preparations

For good adhesion, the substrate must be sound, clean and dry. Any surface damage, dirt, dust, loose particles or other contaminants that may inhibit adhesion must be removed from the surfaces prior to application of the sealant. This can be accomplished with a thorough wire brushing, grinding, sand blasting or solvent washing/priming depending on the situation.

Tremco recommends that surface temperatures be 40 ̊F (5 ̊C) or above at the time the sealant is applied. If sealant must be applied in temperature below 40 ̊F (5 ̊C), please refer to the Tremco Guide for Applying Sealants in Cold Weather that can be found on our web site at


TREMstop Fyre-Sil adheres to common substrates without primers; however, Tremco always recommends that a mock-up or field adhesion test on the actual materials being used on the job be conducted to verify adhesion. The field adhesion test can be found in appendix X1 of ASTM C-1193, Standard Guide for Use of Joint Sealants.


TREMstop Fyre-Sil is used in firestop systems. It is easily applied using conventional caulking equipment.

Clean Up

Cleaning can be accomplished with solvent such as IPA or MEK while sealant is in an uncured state.