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Simple to use and extremely effective, expanding foam is essential if you want to ensure that cracks, gaps, and holes in your home are shored up and sealed. Once it’s applied—whether that’s on wood, plastic, metal, or masonry—it expands to fill the space, creating an often airtight and watertight seal. This unique construction makes expanding foam useful for a wide range of task; apart from typical residential insulation jobs, it's also well-suited for soundproofing, preventing plumbing pipes from rattling around, and even keeping rodents or other pests from sneaking into your home.
Best Expanding Foam
- Best Overall: Loctite TITE FOAM Insulating Foam Sealant
- Best Kit for Large Projects: Great Stuff Pro Gaps and Cracks
- Best Kit for Pests: Great Stuff Pro Kit
- Best for Crafts: Smooth-On Foam-iT! 5 Rigid Polyurethane Foam
- Best Fire Block: Fire Block Polyurethane Foam Sealant
- Best Value: Big Gap Filler
- Best for Smaller Projects: Home Seal
What to Consider
The main factor to consider when choosing an expanding foam is whether it’s going to be able to effectively fill the spaces you’re working on. The recommended expansion capacity is typically stated on the canister, and usually indicates whether or not it’s best for filling gaps measuring less than or greater than 1 inch. If you’re tackling especially small cracks or openings, go with a minimal expansion model. These will expand much less than typical foams, and are easier to use without creating a huge mess to clean up later.
You should also think about how you prefer to apply the foam. While most will feature a straw that directs the contents, others will include a separate gun that you screw the canister into, and which provide much more control and precision.
How We Evaluated
We’ve used expanding foam in many DIY and construction tasks in our career, from smaller sealing tasks to large-scale insulation work in factories and warehouses. This hands-on experience, in addition to online research, helped us evaluate potential options for our list, and we made sure to include a good balance of types and application styles.
Since some users will be tackling much larger sealing projects than others, we included both single canister options as well as two bulk sets with multiple cans. While quality and effectiveness were our top priorities when finalizing our list, we also kept pricing in mind to ensure there's a perfect product to suit your needs, no matter your budget.
Pros
Low cost- Can be used with a variety of surfaces
Cons
- May not be effective enough for large projects
Key Specs
- Size: 12 ounces
- Color: White
- Coverage: 1 inch
This Loctite foam can be used effectively on wood, concrete, brick, metal, and PVC, making it a great multiuse option. Its straw applicator is also convenient for users who would prefer not to worry about a bulky spray gun, and since the foam itself is designed to resist the elements, it's ideal for exterior use.
This foam fills cracks and gaps up to 1 inch in size, which should cover a range of home sealing tasks, but it likely won't be large enough for bigger projects. At this low price, this product is a great value, and definitely worth grabbing just to have on hand when insulation issues come up.
2
Best Kit for Large Projects
Great Stuff Pro Gaps and Cracks
Pros
- Includes gun and cleaner
- Airtight and water resistant
Cons
- May be overkill for small projects
Key Specs
- Size: 12 canisters containing 30 ounces each
- Color: Orange
- Coverage: 3 inches
Combining an impressive expanding capacity—3 inches—with a dozen cans of foam, this Great Stuff Pro kit will have you prepared for a wide range of project sizes in your home. The included applicator gun allows you to maintain maximum control while spraying, and lets you gain access to even the narrowest of cracks.
This kit also includes two cans of gun cleaner so you won’t have to deal with frustrating clogs and jams, and the orange foam color makes it easy to tell where you’ve already sprayed. Whether you need to work with wood, plastic, glass, or brick, this kit will have you covered.
Pros
- Includes rubber gloves
- Not harmful to bees
Cons
- Expensive
Key Specs
- Size: 20 ounces
- Color: Off-white
- Coverage: 3 inches
If you’re looking for a foam to help prevent rodents and other critters from entering your home, this kit from Great Stuff could be the perfect choice. In addition to two canisters of foam, this kit also includes a 4-inch-by-20-foot roll of copper mesh.
When used in conjunction with the foam, this mesh will create an extremely effective barrier against potential pests. The applicator gun also makes it easy to access the tiny nooks and crannies that mice and co*ckroaches can squeeze through. The included can of gun cleaner is a nice perk as well.
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Pros
- Cures in 6 minutes
- Can be pigmented
Cons
- Somewhat expensive
Key Specs
- Size: 1.9 pounds
- Color: Beige
- Coverage: N/A
This Foam-iT! product is specially designed for pouring into molds used in prop-making and arts and crafts. It expands to 10 times its normal volume, making it great for a wide range of project sizes, and cures in just 6 minutes. Although you do need to mix it, the 1:1 ratio makes this step easy for anyone to figure out. Its beige color also allows you to mix your own pigments in and adjust the color to your liking.
It’s worth noting that this foam will cure to a hard, rigid finish, so it won’t be suitable for projects that require a soft or squishy texture.
Pros
- Orange color is easy to identify
Cons
Key Specs
- Size: 12 ounces
- Color: Orange
- Coverage: N/A
This Red Devil foam inhabits the passage of fire through gaps, cracks and openings inside your home—particularly around pipes and plumbing fixtures, air and heating vents, and electrical outlets. It’s recognizable orange color is convenient when tackling comprehensive sealing projects, and the multidimensional applicator allows you to spray it in any orientation.
This 12-ounce can will cover 450 linear feet, and can be used indoors and outdoors. Just like typical foams it will adhere to wood, glass, plastic, metal, and masonry, and once cured, can be sanded, painted or stained if you like.
Pros
- Can fill larger gaps
- Affordable
Cons
Key Specs
- Size: 12 canisters containing 12 ounces each
- Color: Beige
- Coverage: > 1 inch
If you’ve got a large project coming up and want to make sure you get the most bang for you buck, this 12-pack of expanding foam from Great Stuff could be a great choice. At less than $7 per can, this product is not only affordable, but also effective at filling gaps that are larger than 1 inch in size. It’s also sandable, paintable, and stainable, as well as airtight and watertight.
Although it ships in a single box, each canister includes its own applicator straw, making it ideal for jobs that multiple people will be working on.
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Pros
- Minimal expansion is easier to control
- White color blends in easily in many spaces
Cons
- Expensive
Key Specs
- Size: 12 ounces
- Color: White
- Coverage: < 1 inch
This minimal expanding sealant won’t be able to fill the larger spaces that the other options on our list can, but if you have only thin cracks and spaces to tackle, it will get the job done easily and with minimal mess.
Despite its lower expansion capacity, this foam is still water-resistant, and once cured, can be sanded, painted, and stained. Plus, unlike some other foams, this one can be used at a wide range of temperatures, from 30 to 120 degrees Fahrenheit.
Although it’s a bit expensive, the time you'll safe on cleanup with this low-mess foam may make it worth the extra cost.
Alex Rennie
Alex Rennie is a freelance writer who specializes in the Home Improvement, DIY, and Tool space. As a former residential and commercial carpenter, Alex uses his hands-on experience to write practical buying guides, how-to articles, and product reviews. His work has also appeared in Business Insider's Insider Picks, and before his writing career, he was a full-time carpenter living in New York City. There, he worked as part of a team designing, building, and installing large furniture pieces, as well as performing a variety of home repair and maintenance projects. Alex currently lives in Los Angeles, CA, and spends his free time exploring the beaches and mountains with his fiancé and their dog Louie.
