Great Stuff: Air Sealing Foam Insulation
A can of Great Stuff should be hanging out of your back pocket

Great Stuff
When your working to air seal your home, a can of Great Stuff should be hanging out of your back pocket like a monkey wrench in the coveralls of an auto mechanic. Great Stuff has so many uses when it comes to stopping warm air drafts and cold air leaks that the home weatherization professional nor the homeowner, do-it-yourself, should not be without it.
Ever try to stuff a wad of old wash cloth around a plumbing pipe to stop the consistent and chilling flow of cold air? Next time, save the old wash cloth and grab a can of Great Stuff, the job will be easier, quicker, and the flow of arctic air will actually be stopped. Old wash clothes were made for washing cars not holding out the north wind.
Great Stuff is a polyurethane-based insulating foam sealant that fills, air-seals and insulates small gaps (less than 1 inch) inside or out. What you might not have guessed is how easy it is to use (thanks to the straw applicator) or how it expands to take the shape of cracks and voids to form a durable, airtight, and water-resistant bond that eliminates unwanted airflow and helps reduce condensation.
For me, there are two main reasons why a person should grab a can of Great Stuff:
- To reduce energy costs. this insulating foam will expand into most holes and gaps to produce that air tight seal your looking for. The warm air outside can not sneak into your home and cause the A.C. to work harder. And in the winter time, the warm air inside your home can not migrate outdoors and cause the furnace to work longer hours.
- Security against wandering pests and the safety that during a fire, the smoke and flame will not be allowed to spread so quickly. Great Stuff dries tack free in less than 10 minutes and is able to be trimmed in 30 minutes. The insulating foam completes a barrier to crawling insects that no-longer have a hole to crawl through: to rodents who simply do not like to fill their mouths with the stiff foam: and to smoke and fire that cannot find the air space to continue spreading.
Facts and figures about the performance of Great Stuff:
- Forms a permanent weather-tight seal to minimize drafts and insect infestation. I like the word permanent and the fact that water and moisture will not compromise the air sealing benefits.
- Exceptional adhesion to building materials. Personal evidence and experience will support this claim. Great Stuff sticks well to all building materials.
- Interior or exterior use. Some holes and cracks you need to fill from the exterior of the home and some from the interior.
- Tack free in 6 minutes; Trims in 30 minutes. Easy to work with and trim up a little bit after just 30 minutes or so.
- Foam elasticity allows for movement/shifting within a structure. Great Stuff adheres to building materials so well that a little movement in the structure will not keep the foam from hanging tight and remaining in place.
- Paintable, stainable and sandable. Well, let’s just say the painting part goes really well. The sanding and staining can be a challenge that produces less than perfect results.
- Cream colored foam. Maintains a color that blends in and keeps you from rushing right out to grab a rattle can of paint.
- Cures rigid. After Great Stuff dries, it can be effectively trimmed with a saw or utility knife.
- All-direction dispensing. The can can be held upright or upside down in order to get the foam where you need it.
- UL Classified. Yep, the big guys have tested the foam and decided it is OK for you to use.
Tip: Line up your air sealing projects and have them ready for Great Stuff so you can go smoothly from one area to the next. If you air seal one area and then wait until the next day to air seal area number two, the Great Stuff may have dried in the straw or trigger and have a hard time getting started again.
High Heating and Cooling Bills
Air leakage through holes, gaps, and cracks is the single biggest cause of home heating and cooling loss. It actually accounts for up to 50 percent of the energy used in most homes. During a good Home Energy Audit by a certified energy Auditor, a blower door test will be conducted that will measure the amount of air leakage in and out of your home.You will be surprised to find that your home simply has more cracks and holes than you imagined.
Count up all the gaps and cracks around window and door frames, electrical outlets, plumbing lines, under the siding, in the basement, and in many other places, they’d add up to a space the size of a standard window. So essentially, you’re heating and cooling your house year-round with a window open. We suggest closing the window. Use Great Stuff to fill in those gaps and cracks, then sit back and start counting the money you’re saving.
Great Stuff is better than caulk.
Unlike caulk, Great Stuff foam insulation expands to fill gaps and cracks.The foam is also easier to use, dries faster, cures firm and is sandable, paintable and stainable. Not to mention a single 12 oz can equals up to 19 tubes of caulk. Caulk is good stuff, but it’s not the best when it comes to air sealing and insulating..
Great Stuff comparison to a tube of caulk and how many cracks and holes you can fill.
- One 12 oz. can = up to 19 tubes of caulk
- One 16 oz. can = up to 24 tubes of caulk
- One 20 oz. can = up to 30 tubes of caulk
Mold and Mildew
Mold and mildew problems can be health hazards. Some mold and mildew problems occur because warm moisture travels through gaps and then condenses on cold surfaces. When left unchecked, it can cause wood to rot and may lead to respiratory problems for people with mold sensitivities and allergies. In short, it’s a serious problem. Air-sealing and insulating all gaps between the attic and the living quarters with Great Stuff helps prevent mold growth and the potential for health hazards.
Mold and mildew will use caulk as a good place to gain a foothold and start growing and spreading. Not too unusual to see black mold on the caulk around bathtubs and showers. Mold does not like Great Stuff nearly as well caulk.
Great Stuff for the Attic.
What’s hotter than the outdoors on a sunny summer day? Your attic. Keep the heat out of your living space by air sealing your attic with Great Stuff. Use it to seal attic hatch door frames, cable and gas lines, recessed lights, ceiling fans and other penetrations.
Great Stuff for the Living Space.
It’s where you eat, sleep and hang out, so don’t neglect the most important place in your house. Make sure to fill the gaps and cracks in your living space. Use Great Stuff to insulate electrical outlets, seal pipe penetrations, insulate windows and doors, and heating duct boots and registers.
Great Stuff for the House Exterior.
Great Stuff will help maintain and identify your homes air barrier. Maintaining that distinction by insulating your homes exterior with insulating foam can keep critters outside and you’re heating and cooling conditioned air inside. Don’t forget your water faucets, hose bibs and the dryer vent.
Tax credit Resources
The American Recovery and Reinvestment Act of 2009 Manufacturer’s Certification Statement Pertaining to the Energy Policy Act of 2009 (86KB PDF) With the American Recovery and Reinvestment Act of 2009, consumers purchasing and using insulating and sealing materials, including Dow Great Stuff products, could be eligible for a 10% insulation tax credit up to $500 per year. And all 2010 and 2011 purchases qualify.
How Do I Get The Tax Credit?
Save the original store receipts and a copy of the Manufacturer’s Certification Statement in your tax records. Click here for a copy of the Dow statement. Use IRS Tax Form 5695 to file for your tax credit. Keep your records and receipts and follow your tax person’s instructions.
What products do NOT qualify?
Insulation and sealant products used in new home construction do not qualify nor do installation costs. Consult a tax advisor to determine how to qualify and apply for potential income tax credits.
Next time your home is feeling a little drafty and the old power bill is looking a little too high, stop by your favorite variety or hardware store and pick up a can of Great Stuff: Air Sealing Foam Insulation.



