Seal, Insulate, and Reduce Energy Costs


Electrical penetrations, like those threading wires through walls and studs, leave lots of room for air to travel through a home. Plus, if there’s ever a fire, these holes help fuel the spread of smoke and flames. Great Stuff™ Fireblock and Great Stuff Pro™ Gaps & Cracks are fireblock rated and fill those gaps, helping to impede the spread of smoke and flames.



  1. Prep area by removing dust and debris.  
  2. Shake can for 60 seconds.  
  3. Install the dispenser to the product as per directed on label.  
  4. Practice with a dry run.  
  5. Invert can and insert it into the gap around the wires.  
  6. Activate can by pulling the trigger.  
  7. Never allow foam to touch exposed wiring.
  8. Wipe away imperfections with a cloth soaked in Great Stuff™ Foam Cleaner.  
  9. Foam should be tack-free in 10 to 15 minutes.  
  10. Store or dispose of the product as per directed on label. 


Helpful Tips:

If using Great Stuff Pro™ with Foam Dispensing Gun, follow these additional steps before application:

  1. With the can secured, set your desired bead size by adjusting the flow control knob on the back of the gun (bead can be adjusted from 1/8"-3"). Then, pull the trigger to fill the gun with foam, dispensing excess foam into an appropriate waste receptacle. Lastly, test the bead size before applying.
  2. Shake vigorously for a minimum of 60 seconds. If the can sputters, simply shake the can while held upside down.
  3. Any uncured product that gets on the skin can be removed with acetone.  
  4. Best results if used when product temperature ranges from 60-90°F (15-32°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.
  5. Firmly screw straw assembly onto valve and dispense SLOWLY.
  6. Mist with water to speed cure.
  7. Trim cured foam with serrated blade.
  8. If applied outdoors, be sure to paint or cover foam to prevent discoloration and UV damage.
  9. Great Stuff ™ cans featuring the straw tube applicator will seal shut if left to sit for more than 2 hours after its last use.
  10. 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:
  11. Thread the Smart Dispenser™ onto the valve until it is secure, ensuring there is no gap between the dispenser and the valve.
  12. Do not unwind the dispenser after you have started using it.
  13. 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.
  14. Tighten the flow control screw until fully closed for storage. Use can within 30 days of initial use.
  15. Store upright with a foam dispensing gun attached.
  16. Fill gaps <50%
  17. Always leave a can of foam attached to the gun with the flow control screw closed.
  18. When ready to change cans, shake the new can of foam for a minimum of 60 seconds.
  19. NEVER leave a gun without a can of adhesive without a can of Great Stuff Pro™ attached unless the gun has been thoroughly cleaned with Great Stuff™ Foam Cleaner.
  • Eye protection
  • Gloves
  • Cloth
  • Great Stuff™ Foam Cleaner
  • Great Stuff™ product of choice
Product Solutions


Helps impede the spread of fire and smoke through service penetrations between floors, electrical outlets and runs through wall studs, pipe, cable, duct penetrations and more.



Bonds to wood, metal, masonry, glass and most plastics to fill gaps and cracks up to 3" while blocking the spread of smoke.