16 Spray Foam Attic Insulation Pros and Cons

Conversations about the type of insulation that you use in your attic at home might not be the most exciting to have, but it is also a critical decision for you to make. When you have the correct R-value in your home for your region, then you can maximize the impact it has on your heating and cooling needs. Adequate insulative products will keep heat in during the winter and prevent it from coming in during the summer months.

Because your indoor temperatures are regulated more effectively when using the correct insulation, you can save a lot on your monthly utility expenses. In past generations, builders would often use fiberglass insulation as the primary method of insuring that your structure can benefit from this feature. A new option to start thinking about if your home could use an upgrade in the attic is spray foam insulation.

Although spray foam is a relatively new method of providing insulation for a home, you can use it as a primary or supplementary option to ensure your home has the correct R-value. Installers will apply it to your walls and ceilings, which then allows it to expand to fill in the gaps that are between your joists.

If you are looking for an affordable insulation option for your attic, then here are the pros and cons to consider with spray foam.

List of the Pros of Spray Foam Attic Insulation

1. It provides a seal that is air-tight.
When spray foam insulation is applied to your attic, then you will create a fast seal thanks to the expansive nature of this product. If you have any holes or cracks in the space, then the foam will penetrate the area to give you a better insulation experience. There are fewer leaks found after this product is correctly installed, which means your energy efficiency levels can rise significantly. You will notice the insulative qualities immediately.

2. Closed-cell spray foam eliminates corners and gaps.
When you use open-cell spray foam, newsprint, or even insulation, there is an excellent chance that some of the corners between your joists will be missed – even if the product is correctly installed. If there is warpage or unusual structures in your attic to cover, a standard insulation product may be unable to provide you with the results that you want. Choosing a closed-cell spray foam allows you to fill in any unusual features quickly without customizing the shape or installation method. That is why it is such a robust option for the average home.

3. You will receive a significant level of water resistance with this product.
Spray foam insulation is impermeable to water, which means you can reduce the amount of moisture that comes into your attic during storms or as the seasons change. Unlike paper insulative products (which includes fiberglass because of its backing), you don’t need to worry about the foam absorbing the moisture to promote mold, mildew, and fungi growth in your home either. Over the lifetime of your structure, the risks of damage because of insulation problems are significantly reduced using this option compared to the traditional products that installers use today.

4. It does not act as a food source for organic materials.
Even if there is moisture in your attic from a leaking plumbing line, a swamp cooler, or a similar issue, the spray foam insulation will deter the growth of organics in your home. It is made from inert polymers that do not become a food source for mold, mildew, or fungi when it becomes wet. You will want to choose a closed-cell option to maximize this advantage, but both options are better than the use of an organic insulation product. It even resists pests since it functions more as a solid block instead of a filler like traditional products.

5. Spray foam insulation is friendly to the environment.
Not only does the use of spray foam insulation in your attic reduce the impact your home has with its overall energy consumption, but it also uses fewer materials to ensure you receive the correct R-value. This benefit extends to the wear-and-tear on the structure, which means fewer repairs are needed. That creates an additional reduction in the materials used as well. Although the spray function may contribute some to landfill waste in some situations, the net gain you achieve is far superior to the other insulation options which are available today.

6. It lasts longer than other forms insulation when correctly installed.
When an installer places spray foam insulation in your attic, then you are receiving a product which can last indefinitely in your home without experiencing a significant degradation in its quality. The lifespan of this product will usually be as much, if not more, then the amount of time you will spend in the home. Professional inspectors rate it as lasting for more than 80 years, with some options rated for more than a century.

7. The foam can provide an additional layer of strength to your roof.
When you have spray foam insulation applied to your attic, then the rigidity of this product after it cures can provide more stability to the structure of your house. With the added boost in structural integrity, it is not unusual to experience better noise reduction levels from outside of the home when correctly installed. The premium insulation products in this category can more than triple the racking strength of your roof that can last for several decades since the product does not sag or shrink with proper maintenance and supportive weather conditions.

8. It will not lose is insulative value over time.
Fiberglass insulation often sees a reduction in its R-value as it ages due to the wear and tear it encounters throughout its life cycle. Spray foam insulation offers a different experience. Even though it may not provide enough of an insulative value in some geographic regions, you will not see a decrease in what is possible over time. Because you may need to remove drywall to update your insulation with traditional items, the overall expense for an upgrade with this product is comparable to what you would have for other forms of insulation in your attic too.

9. Spray foam helps to reduce contaminants from entering the attic.
This benefit goes back to the solid nature of this insulation. Because it offers an impermeable solution, you may discover fewer pollens and other indoor contaminants inside that could reduce the quality of the air you breathe. This advantage can improve the efficiency of your HVAC system as well, further reducing your energy costs over time.

List of the Cons of Spray Foam Attic Insulation

1. Professional installers can still make errors with attic placement.
Attics are filled with unusual shapes, gaps, and spaces where air bubbles can form when spraying foam insulation between the joists. The expansive nature of this product can reduce the chances that there are pockets that can reduce the R-value of the installation, but it does not eliminate them. If your installer does not layer the product correctly, then even closed-cell products can form trapped spaces for air. Your structure can also shift or change over time, which the spray foam insulation will not do.

2. It could encourage additional water damage in some situations.
If your installer misses a gap or cavity in your attic, then you will have a much higher risk of suffering water damage to your home in the future compared to other insulation products. Because the density of the foam prevents the moisture from traveling through the insulation, it will sit in that pocket until it evaporates. That exposure can increase issues with rot and insect infestation, depending on your geographic location.

3. Some types of spray foam insulation can shrink over time.
The expansive nature of spray foam insulation is definitely one of its advantages, but this product is also known to shrink in some situations. As the product begins to age in your attic, the constant exposure to temperature changes can cause the cells to reduce in size, creating shrinkage that reduces the level of coverage that you receive. If this situation occurs, then the foam will pull away from the framing in the attic, which will then cause your home to be less energy efficient as well.

4. It may not meet your building codes, even when professionally installed.
There can be a significant difference between the thickness of what your spray foam insulation requires to provide protection compared to what your local building codes mandate. You will receive between 3 to 4 in R-value for every inch of spray foam insulation that is placed in your attic. If your joists will only support three inches of this product, then your maximum value would be R-12. Should your local building codes require R-17 or higher, then you would need to use this product as a supplementary option instead of as the primary insulative product for your structure.

5. You must give this product additional time for curing.
Spray foam insulation in your attic is not a product that you can install and use immediately. You must give it time to expand and cure so that it can provide the highest level of protection for your home. Because this product emits a gas during this process that can cause challenging physical symptoms with exposure that include breathing problems, you will need to be out of the home for between 24-72 hours until the product is ready. There is always a small chance that the foam preparation is incorrect, which could cause it to emit this gas indefinitely because it does not ever full cure.

6. Spray foam insulation for the attic can be somewhat expensive.
If you were to utilize a standard fiberglass insulation in your attic, then the cost in some geographic areas would be about 40 cents per square foot. Choosing spray foam for this need instead could cost you well over $6 per square foot in some markets if your R-value code requires that you use four inches of product to achieve the correct levels of energy efficiency. If you have a usable attic with over 70 square feet, the difference in expense could be significant.

7. Installers must be certified in most communities to provide this service.
A significant amount of experience is necessary to correctly apply spray foam insulation in the attic. Your contractor must use specific personal protective equipment to ensure they are not exposed to the fumes that this product can produce. Open-cell installations are particularly challenging since the foam can fold on top of itself during the application, creating pockets of air that the installer must correct to ensure your home receives the protection that it deserves.

The pros and cons of spray foam insulation for the attic prove that it can be an affordable and useful option in many homes around the world. The density it offers can protect your home from air or water leaks, supporting the overall health of the structure. It must be installed correctly and inspected regularly to maximize its lifespan, so keep each key point in mind while looking at all of your options to determine if this product is right for your home.

About the Author of this Blog Post
Natalie Regoli is a seasoned writer, who is also our editor-in-chief. Our goal at Green Garage is to publish the most in depth content on the internet for every topic we write about. If you would like to reach out to contact Natalie, then go here to send her a message.