Thanks to the sheer volume of information available on the topic — some accurate, some not, and some outdated — it’s all too easy to develop misconceptions about spray foam insulation. This is a building material that’s experienced vast technological improvements in the recent past. Information on foam insulation that was accurate 20 years ago may be entirely incorrect today. There’s also a wide enough range of different foam products that you can’t trust too many blanket statements to accurately fit all foams.

Common Foam Insulation Misconception

False: Closed Cell Insulation Increases A Home’s Structural Integrity

Closed-cell spray foam insulation is a tremendously durable product, but it’s not in the same league as the wall studs around it. Exterior wall materials, too, are far stronger than the insulation. In fact, the sheet of drywall on the inner face of your wall contributes as much or more to the wall’s overall strength.

False: Spraying Foam In An Attic Can Damage The Shingles Above

This is a case of badly outdated information sticking around long after it’s obsolete. When spray foam insulation was first introduced, some people theorized that the insulation itself would emit heat and potentially damage the shingles on the outside of the roof. Like other forms of insulation, foam merely makes a barrier between two regions of different temperatures. A well-insulated attic with minimal ventilation might produce a very slight increase in the average temperature of your roof, it’s far too small a change to pose any threat to your shingles.

False: Foam Insulation Shrinks As It Ages

Although it’s possible for foam insulation to shrink or experience other problems after installation, this is an issue caused by improper mixing or application. When installed by professionals, foam insulation never shrinks.

False: Foam Can Only Be Sprayed In Warm Weather

We can install spray foam insulation in any climate conditions. As long as it is safe for workers to be outside the house, it’s possible to install foam.

False: Foam Insulation Makes It Impossible To Do Electrical Work In The Insulated Walls

Open-cell foam insulation is pliable. This means it is easy to cut, remove, and reshape for post-installation work like rewiring.

False: Foam Insulation Seals Gaps Around Doors And Windows

Foam insulation is good at filling every part of the space where it’s installed. But there are cavities around wall openings (doors and windows) where injected foam won’t reach. These cavities can be foamed during new construction. The cavities can’t be accessed after construction is complete — but don’t worry, we have a fix for this.

False: Foam Insulation Makes It Impossible For Your House To “Breathe” As It Should

When we talk about a house being able to “breathe,” what we’re really concerned about is the air quality and humidity inside. This is ultimately a matter for your HVAC contractor; a properly-designed system will ensure that your home is adequately ventilated and not “tight.”

False: Foam Insulation Retains Water, Causing Problems Like Mold

Early forms of open-cell foam insulation did, in fact, retain water. This is no longer an issue for homeowners, though. Modern open-cell foam does not retain water and does not promote the growth of mold or mildew.

False: Drywall Has To Be Torn Down To Insulate Existing Exterior Walls

Rest assured, you absolutely can install foam insulation in your exterior walls without ripping out your drywall. In fact, we can install insulation from the outside. We have a range of different procedures for this depending on your home’s exterior siding.

False: Foam Insulation Is Flammable

Both the injection foam and spray foam that we use are Class 1 Fire Rated. This means that they don’t promote the spread of fire. These foams will extinguish themselves after they are no longer exposed to flame. They are entirely non-toxic and environmentally safe, too.

False: Foam Insulation Costs More (A Lot More) Than Fiberglass Or Cellulose

While it’s true that foam insulation typically costs two to three times as much as fiberglass or cellulose insulation, that relationship only holds for the day-one installation cost.

Foam insulation is much more durable than any traditional alternative, requiring no maintenance or replacement. As long as the insulation remains undisturbed, it will never need to be replaced.

Foam insulation is also a long-term savings producer because it reduces your energy bills for heating and cooling. Proper foam insulation creates an air seal, keeping your conditioned air inside your home and keeping exterior air from getting inside. With fiberglass or cellulose insulation, you still have to worry about air leakage driving up your heating and cooling costs.