Batt Case

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Spray Foam Insulation: An Airtight Alternative

Remember when insulating the attic was an arduous task requiring fiberglass batts and staples?  And then your wife would say something like, “Honey, why do you spend so much time in the attic?” to which you would reply, “I paid for this damn house, you show me some respect!”  Well, that was a thing of the past now that spray foam insulation is providing a quick, airtight alternative.  Spray foam insulation- keeping families together, just as it keeps heat from escaping through the walls.

What is it?
Spray foam insulation is readily described as an insulating and air-sealing product used primarily on residential wall and ceiling cavities.  The foam itself is a liquid that contains a polymer and a foaming agent which causes it to expand about 100 times its initial volume once applied.  Therefore, as it expands, it essentially fills in all air gaps, eliminating cracks and spaces that standard fiberglass insulation cannot avoid.

The two-component mixture is sprayed from the nozzle of a gun (easy there Dirty Harry, we’re not talking about a .44 Magnum here, but rather a specialized spray foam gun) into wall, ceiling, or floor cavities, where it expands and seals off any remaining gaps.  After it fully expands, you may have to trim or shave away any excess foam that extends past any studs, therefore making your job easier once you’re ready to drywall.

There are generally two types of spray foam available: open-cell and closed cell.  If possible, you should shoot for closed-cell (polyurethane), as these types of foam have a higher R-value (construction industry term used to measure thermal resistance).  Whereas open-cell foam might allow water vapor and liquid water to penetrate the insulation, closed-cell foam is non-porous, thereby ensuring that no moisture will penetrate the insulation.  This can be important, as any excess moisture build-up could result in mold.

Ideally, if insulation only needs to be administered in several small spaces or in a small part of the wall, you can save money by buying a tank of spray foam from a local contracting company.  However, if the job requires more than a few quick sprays, professional contractors are the way to go, as they should be more readily equipped to handle large-scale jobs that may require other specialized tools.

Who needs it?

If you’re having heating problems in your house, there’s no better way to insulate than spray foam.  Spray foam also works well in tight spaces, making it an ideal choice for insulating around outlets or on steel framing.  Also, contracting companies such as Green Advantage Insulation are catering to those environmental-friendlies out there by offering a spray foam job that requires no HCFC blowing agents, which contain ozone depletion potential.  And let’s face it, spray foam is fun, or at least a lot more fun than stapling fiberglass batts and blankets.  Put it this way, there’s no other way to explain the invention of cheese wiz, other than that it’s fun to spray.


If you’re going for hermetic sealing (which, if you’re insulating, should be your top priority) than spray foam insulation is considered the best.  It can be applied between joists and rafters, which is a lot more difficult when using other methods.  In some cases, spray foam can be fireproof, most commonly in cementitious foam.  Also, spray foam greatly reduces the risk of mold, mildew, and airborne dust forming within pockets between the walls, as pockets are eliminated (which dually cuts down on trolls and pocket-dwellers alike).  And best of all, spray foam insulation could potentially increase your property value, as it increases structural stability of exterior walls and roofs.


While spray foam is considered the top method of insulation, you should be somewhat knowledgeable on the subject before you try using it yourself.  There are many different spray foam insulation products on the market, so you should be cognizant of which ones contain open-cell foam and which ones contain the more superior closed-cell foam.  Likewise, you should be conscious of the chemicals that some foams contain, as they can potentially be detrimental to the environment and in some cases, to your household.

Also, it is important to remember that if you plan on insulating yourself, you take the proper precautions, such as wearing a protective mask and goggles.  That’s the least you can do, as professionals are often decked out in what look like full-on beekeeper uniforms.  They actually kind of look like Ghostbusters with their zip-up onesies and spray guns/tanks that suspiciously look like proton packs.

The bottom line

If you need to insulate for any reason, there’s not a better solution on the market than spray foam.  With all the different kinds available, you should be able to find one that suits your needs, whether that means that it’s cheap, it’s environmentally-sound, or fireproof.  Either way, it will seal to airtight perfection.

About the Author

Kyle Donley is a writer for Yodle, a business directory and online advertising company. Find a Contractor or more Heating and Air Conditioning articles at Yodle Consumer Guide. Spray Foam Insulation: An Airtight Alternative

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