3M™ Fire Barrier Pillows

Wire Mesh is No Substitute for 3M Technology


What's special about fire barrier pillows?

  • Fiber barrier pillows designed to prevent the spread of fire.
  • 3 hour UL Listed systems and tested to UL 910 flammability test.
  • UL Listed systems up to a 540 sq. in. opening
  • Easy retrofit - remove and replace pillows, as needed.
  • Click for More Features
  • UL Classified

The 3M™ Fire Barrier Pillow is a self-contained, highly intumescent product designed to firestop a wide variety of through-penetrations including cable trays (up to two per opening) and conduit and blank openings, which penetrate fire-rated construction.

Part # Package Size Weight Price
FP-3M-FBP-2-4 2" x 4" x 9" .53 lbs.
Manufacturer Direct
FP-3M-FBP-2-6 2" x 6 " x 9" .4lbs.
Manufacturer Direct

UL listed


During a fire, 3M™ Fire Barrier Pillow intumesces (expands) and locks itself into place, completely surrounding the penetrant(s) stopping smoke, fire and toxic gases from spreading to the next room or next floor for the rated time period. They are easy to install and great for retrofit projects. Just remove and replace pillows as needed.
3M Fire Barrier Pillows have been tested to the ASTM E 814 test criteria and have been designed to meet the intent of NEC, NFPA, SBCCI, BOCA and ICBO building codes.
The 3M™ Fire Barrier Pillows achieve up to 3 hour fire ratings when tested by Underwriters Laboratory, Inc. in accordance with ASTM E 814 (UL1479).

  • Graphite free composition.
  • Multiple sizes available.
  • Red Color- Easy to inspect

    Typical Physical Properties
    Blanket Color: 3M Red
    Density: 6 PCF (nominal)

    3M Fire Barrier Pillow has been tested in accordance with ASTM E 84.

    Density: 6 PCF (nominal)
    Heat Expansion Begins: 392°F (200°C)
    Significant Expansion Begins: 536°F (280°C)
    Volume Expansion: 18% (calculated)


    L Rating: See UL Listing.

    Installation shall be in strict accordance with manufacturer's written instructions. The product shall be classified by Underwriter's Laboratory, Inc. as a Fill, Void and Cavity Material. When installed in accordance with systems outlined in the current UL Fire Resistance Directory and tested in accordance with ASTM E 814 and (UL 1479), up to a 3 hour rating is achieved.


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    How-To Corner



    Installation Techniques:
    1. Install 3M Fire Barrier Pillows so the 9 in. (22,8 cm) dimension travels through the wall, or floor.
    2. One of the large faces of the 3M Fire Barrier Pillow shall face the framing of the penetration.
    3. A mixture of following pillows may be necessary to obtain the correct compression (20% - 25% compression).
      FB 249: 2 in. x 4 in. x 9 in. (50,8 mm x 101,6 mm x 228,6 mm)
      FB 269: 2 in. x 6 in. x 9 in. (50,8 mm x 152,4 mm x 228,6 mm)
      FB 369: 3 in. x 6 in. x 9 in. (76,2 mm x 152,4 mm x 228,6 mm)
    4. Begin by installing as many FB 369 pillows, as possible. Then install additional FB 269 and FB 249, as needed, to complete the installation.

    The 3M Fire Barrier Pillows must be stored in a dry warehouse environment. Pallets should not be stacked.

    1. Choose the appropriate firestop system in the 3M Fire Protection Products Applications and Specifiers Guide, or the UL Fire Resistance Directory.
    2. Starting in the bottom corners of the penetration, install 3M Fire Barrier Pillows vertically so that the large faces of the pillows are facing the framing. See picture.
    3. Fill in the space between vertical pillows with pillows installed horizontally in rows.
    4. Repeat steps 2 and 3 until the penetration is completely full. See Figure 2.
    5. If required, apply a minimum 1 in. (25,4 mm) depth of 3M Moldable Putty+ in all four corners between the vertical pillow and framing.
    6. Check for any openings between pillows (and penetrating items) greater than 1/16 in. (1,5 mm)
      Fill any openings between 1/16 in. (1,5 mm) and 1-1/2 in. (38 mm) with a minimum 1 in. ( 25,4 mm) depth of 3M Moldable Putty+.
    Calculating Pillow Requirement:

    Measure the opening, in inches, and multiply the length by the width to get the total area. Estimate the area occupied by the penetrating items and subtract it from the area of the opening. This is the amount of area to be firestopped.

    For example, an opening through a gypsum wall measures 30 in. x 18 in. (76 cm x 45 cm).
    The openings area 30 in. x 18 in. (76 cm x 45 cm) is 540 sq. in. (3483 sq. cm). A 24 in. x 4 in. (60,9 cm x 10 cm) cable tray which is 40% full of cables is running through the opening. The tray occupies an area 0.4 in. x 24 in. x 4 in. (10,1 mm x 60,9 cm x 10 cm) of 38.4 sq. in. (247,7 sq, cm). The amount of area to be firestopped 540 sq. in. – 38.4 sq. in. (3483 sq. cm - 247 sq. cm) is 501.6 sq. in.

    After calculating the amount of area to be firestopped determine the number of each size pillow needed to firestop the penetration. In most penetrations you will need to use some of each of three sizes of pillows. Determine the number of each pillow by dividing the total area by the pillows Estimating Number and round up the nearest whole pillow.

    illustrating application of fire barrier pillows


    Warranty and Limited Remedy:

    This product will be free from defects in material and manufacture for a period of ninety (90) days from date of purchase. 3M MAKES NO OTHER WARRANTIES INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
    User is responsible for determining whether the 3M product is fit for a particular purpose and suitable for user’s method of application. If this 3M product is proved to be defective within the warranty period stated above, your exclusive remedy and 3M’s sole obligation shall be, at 3M’s option, to replace or repair the 3M product or refund the purchase price of the 3M product.

    Limitation of Liability:

    Except where prohibited by law, 3M will not be liable for any loss or damage arising from the use of this 3M product, whether direct, indirect, special, incidental or consequential, regardless of the legal theory asserted, including warranty, contract, negligence or strict liability.

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    Questions & Answers


    I need a product that is UL listed to firestop large mc cable penetrations which are penetrating the fire rated assembly at an angle

    Asked by Anonymous user on 06.38 PM Wednesday, 30 December, 2015

    • - These pillows are rated to 3 hour per ASTM E 814 (UL1479). You may need to consult your local inspector to confirm that this test and rating are sufficient to meet the requirement for that application.

      Steve S. on 01.05 PM Friday, 19 February, 2016

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