Insulating Foam Sealants

Fireblock with Smart Dispenser™

  • Expands to fills, seals, and insulates gaps up to 3/4 inch
  • Smart Dispenser™ provides precision, control, reusability
  • Impedes spread of fire and smoke through service penetrations2
  • Orange-colored foam for easy identification and inspection

It's about time...You don't know how many cans I lost due to poor dispensing.

-Mark L

  • More Product Details

    GREAT STUFF™ Fireblock Insulating Foam Sealant is a ready-to-use, minimal-expansion insulating foam sealant that fills and insulates gaps up to 3/4 inch to restrict airflow. This distinctly orange solution seals electrical wiring run through wall studs as well as service penetrations in walls and between floors to provide a simple, cost-effective way to maintain the continuity of an approved fire block material throughout the house.

    • Expands to fills, seals, and insulates gaps up to 3/4 inch
    • Adheres to wood, metal, masonry, glass and most plastics
    • Impedes spread of fire and smoke through service penetrations2
    • Tested according to ASTM E84, ASTM E814 (modified), UL 1715
    • Seals service penetrations between floors
    • Seals electrical runs through wall studs
    • Forms a long-lasting, airtight and water-resistant barrier
    • Tack-free in 5-15 minutes3; trimmable in one hour
    • Orange-colored foam for easy identification and inspection
    • Cures rigid in 8 hours
    • All-direction dispensing.
    • UL classified

    1 Read all instructions and (Material) Safety Data Sheet ((M)SDS) carefully before use.

    2 Intended for use in residential application to maintain the continuity of an approved fire block material.

    3 70 ± 5°F and 50 ± 5 % RH, 1-inch bead diameter, 6-inch length. The cure rate is dependent on temperature, humidity, and size of the foam bead.

    • Shake vigorously for a minimum of 60 seconds. If the can sputters, simply shake the can while held upside down.
    • Any uncured product that gets on the skin can be removed with acetone.
    • Best results if used when product temperature ranges from 60-90°F (15-32°C). Optimal 75°F (23°C). The can should not be exposed to temperatures more than 120°F. Cured foam should not be exposed to temperatures in excess of 240°F.
    • Firmly screw straw assembly onto valve and dispense SLOWLY.
    • Fill gaps<50%
    • Mist with water to speed cure.
    • Trim cured foam with serrated blade.
    • Not to be used for filling closed cavaties or voids. Not for use in aviation, or food/beverage contact, or as structural supprt in marine applications.
    • If product does not flow easily, do not force product from can.
    • If applied outdoors, be sure to paint or cover foam to prevent discoloration and UV damage.
    • Check for expiration date on the bottom of the can as product may not dispense after date displayed.
    • For GREAT STUFF™ SMART DISPENSER™, follow these additional steps before application:
    • Great Stuff™ cans featuring the Smart Dispenser™ may be reused up to 30 days with the straw left attached to the canister, just clean the tip after your first use.
    • For best results:
    • Thread the SMART DISPENSER™ onto the valve until it is secure, ensuring there is no gap between the dispenser and the valve.
    • Do not unwind the dispenser after you have started using it.
    • Let up on the trigger slowly to release pressure in the straw and prevent spurts during the next use and to achieve the most consistent bead.
  • Q.Can Great Stuff™ products be used outdoors?


    Great Stuff™ and Great Stuff Pro™ products can be used outdoors. However, cured foam will discolor if exposed to ultraviolet (UV) light. If left exposed, the foam will eventually crumble. Paint or coat foam for best results in outdoor applications. Great Stuff Pro™ Gasket is not approved for used outdoors

    Q.Can I use Great Stuff™ and Great Stuff Pro™ foam to air seal my electrical receptacles?


    Great Stuff™ and Great Stuff Pro™ foam can be used to air seal around and behind electrical boxes and insulated wires but should never be used inside a box where it may be exposed to bare copper wires

    Q.How do I get Great Stuff™ foam off of my skin?


    If the foam has not cured or hardened, use fingernail polish remover (with acetone); a polyglycol-based skin cleanser or corn oil may be effective. Then wash with soap and plenty of water. If the foam has hardened, there is no solvent that will remove it. It will not harm your skin and will wear off over time. To remove cured foam from skin, use a pumice stone (available at most drug stores) and warm, soapy water. Then apply petroleum jelly.

    Q.What is Great Stuff™?


    Great Stuff™ is the brand name for a line of one-component insulating foam sealants that can help make your home more comfortable and energy efficient by sealing the gaps and cracks where air conditioned and heated air escape. Great Stuff Pro™ Polyurethane Foam Sealants can be used for both small and large air sealing and retrofit applications by DIY’s or professionals. Great Stuff™ comes in cans with a straw applicator or the new patented Smart Dispenser™. Cans are in 12, 16, and 20 oz sizes. Great Stuff Pro™ series is available in larger cans (20,24, & 30 oz sizes) and use the dispensing guns to apply.

    Q.What is the Great Stuff Smart Dispenser™?


    The Smart Dispenser™ from the Great Stuff™ brand is a game-changing, industry best dispenser for one component can sealants.

    Addressing all of the pain points of standard straw dispensers, the Smart Dispenser™ uses integrated mechanical parts to improve the user experience with Great Stuff Insulating Foam Sealants:

    Reusable up to 30 days; use it again and again!

    No dripping; the foam stops as you stop, as the trigger is released the foam ceases to dispense.

    Increased precision with more control and less mess, air seal with ease with the Smart Dispenser™.

    Q.Where can I use Great Stuff™ Fireblock?


    Great Stuff™ and Great Stuff Pro™ products can be used in a variety of interior and exterior applications, most commonly in air sealing and home retrofit applications. Most common application include:


    Pipe penetrations

    Exterior of electrical outlets

    Exterior of electrical penetrations

    Pipe penetrations

    Bathroom fans

    HVAC penetrations


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