• TREMstop Fyre-Sil SL
TREMstop Fyre-Sil SL

TREMstop® Fyre-Sil

Gun-Grade Silicone Sealant

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

Self-Leveling Silicone Sealant

TREMstop® Fyre-Sil SL is a self-leveling, neutral-cure silicone sealant designed for use in firestop applications, including both joints and throughpenetrations.


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.

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  • What is the rating on Tremco's fire caulk?

    Firestop products are tested, but they themselves do not carry a rating. The firestop systems carry ratings that can vary from 1 to 4 hours for any given product application. The firestop system consists of the assembly or construction, the penetrating item, and the firestop product and other required accessories.

  • What is an F Rating? T Rating? L Rating? W Rating?

    F Rating simply stands for fire resistance, and a system should be chosen that matches the F Rating to that of the assembly that is being penetrated.
    T Rating stands for temperature due to the transmission of heat through the firestop. 
    L Rating stands for leakage, and determines resistance to air passage through the firestop. 
    W Rating stands for water leakage, and determines the water resistance of the installed firestop system.

  • Are firestop products paintable?

    Our acrylic products (TREMstop Acrylic GG, TREMstop Acrylic SP, TREMstop IA+) accept paint. Silicones (Fyre-Sil and Fyre-Sil SL) will not accept paint.

  • How much firestopping is required for a 2-hour rating?

    It depends. The system will tell you the quantity of firestop required, and it varies from system to system. The system will also define any additional accessories that are required, such as mineral wool or backer rod.

  • Can I loosen the firestop product up by adding water or other solvent?

    Absolutely not. Firestop products are manufactured under tight regulation to ensure product consistency to what was tested. Any deviation to the product may deteriorate performance.

  • Is your product compatible with competitor products?

    It is never a good idea for competing products to be placed in the same opening, even if it can be determined that they are chemically compatible.

  • What is the movement capability of the firestopping products?

    This answer to this question is less about the ability of the product, and more about the capability of the fire-rated joint system. While a product may display more movement capability than a tested system might indicate, the systems are fire tested at full extension of the joint, which is significantly more severe condition than simply moving a joint system. Each firestop system defines the specific movement capability.

  • If I have a 2-hour condition, but the system is for 3-hour, can I use this system?

    As long as the system is installed in accordance with the design, any system of higher rating can be placed in a lower rated assembly.

  • How do I clean product spills (clothing/carpet/concrete)?

    Acrylic products can be cleaned with warm water and soap, but this should be done before curing. Red pigment can stain and may require abrasive removal. Silicone products require xylene or similar solvent to clean from surfaces, but likely will stain and/or leave remnants on porous surfaces especially after curing. Keep in mind, these products are designed to adhere well to surfaces.

  • How do I prepare a surface for firestop application?

    All surfaces should be clean from debris, rust, oils, or any other contaminant and should be free from frost or surface moisture. Any common sealant surface preparation would be common to firestopping as well.

  • How do I know if the product is still under warranty?

    Product packaging is date coded and most of our products have a 12-month shelf life and are warranted against manufacturing defects for that time period. The product data sheets are more specific on the shelf life of each product.

  • Is your product CPVC-compatible?

    TREMstop IA+, Fyre-Sil and Fyre-Sil SL have been approved as compatible with CPVC by Lubrizol as part of the FGG/BM/CZ compatibility program.

  • What product would you recommend when you want to provide a water-resistant seal?

    Our silicone products (Fyre-Sil and Fyre-Sil SL) have proven through testing and W Ratings on firestop systems to be very effective water-resistant solutions after installation. The surface, during application, must be free of debris and dry.

Projects Using TREMstop Fyre-Sil

SW Florida Regional Med. Center - Gulf Coast Hosp.

Naples, FL

It's imperative that an air barrier system on a medical center or hospital accounts for different temperatures and humidity parameters.

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