Can Spray Foam Insulation Fail?

You’ve likely heard great things about spray foam insulation from friends or family. Your friends claim to have saved money on utility bills and to be living in a much more comfortable space. You have a project needing insulation, so you’ve decided to look into spray foam yourself. But as you’ve done more research, you’ve read some horror stories.

You know insulation is a significant investment. You want the benefits that others are enjoying, but it feels like a gamble. Can you be guaranteed that this will be a good use of time and money?

The truth is that spray foam insulation can fail. But why does it fail? Can failure be avoided?

South Central Services has installed spray foam insulation in hundreds of homes around Greencastle, PA. We have never had a complete installation failure, and have only had to make minor repairs on less than 1% of our jobs.

We know the variables that can lead spray foam to fail. Nothing is more frustrating than hearing stories of people who believed they were making the best choice for their home and were left with a mess instead. We don't want that for you. So let's talk about it.

By the end of this article, you'll know:

• What it means for spray foam insulation to fail
• What causes spray foam insulation to fail
• How to prevent spray foam insulation failure as a homeowner
• What to do if spray foam insulation fails

What Does It Mean For Spray Foam To Fail?

When we say that spray polyurethane foam insulation (SPF) failed, two problems could be at play: off-ratio foam or failure to install the foam within the manufacturer’s guidelines. Let's examine these issues in more detail.

1. Failed Foam Can Be Off-Ratio

Off-ratio foam is a serious issue, which means equipment failure during installation that the installer did not catch and correct. Off-ratio foam is unstable and should never be left as a finished product in someone's home.

Spray foam is created from two liquid chemical components in a 1:1 ratio. These chemicals have health risks in their raw state. After a successful chemical reaction, those health risks are gone.

But off-ratio foam results from an unsuccessful chemical reaction, with some amount of one chemical lingering. As a result, off-ratio foam can produce off-gassing of toxic fumes. The components that create spray foam are supplied in a 1:1 ratio, so having too much of one chemical is a matter of equipment failure.

A competent spray foam contractor will recognize, remove, and dispose of off-ratio foam during the initial installation.

2. Failed Foam Can Fail To Adhere

On-ratio foam that is installed outside of manufacturer’s guidelines can have adhesion problems. Adhesion problems mean that the foam failed to stick to the substrate it was sprayed against: wood, brick, concrete, etc. While this failed foam is still a safe foam, it is not an effective insulation.

One of the reasons spray foam is so effective at insulating is because the plastic foam does not conduct heat well. But spray foam is also an excellent insulation product because of its airtight seal. Spray foam completely seals off cavities, making them airtight. Spray foam can keep out temperature changes, leaking airflow, and allergens. Closed cell spray foam also becomes a vapor barrier at 1.5 inches, which keeps out moisture.

If spray foam does not adhere, there is no airtight seal. So while the foam itself will help to insulate, it would not be effective. Heat, air, moisture, and allergens can pass through freely. Any of those could compromise the efficiency of the insulation or cause damage to the home.

These are the technical explanations. If you see stories of failed spray foam online, this is what happened. But how did it happen? Why did the spray foam fail?

What Causes Spray Foam Insulation To Fail?

There are a lot of factors that can influence the success of spray foam application when contractors are installing it. Some of these are factors that homeowners don't even think about. Manufacturers consider these factors when creating spray foam components and guidelines for ideal application. Here's a preview.

1. Weather conditions
2. Component temperature
3. Substrate conditions
4. Using the wrong foam

Let's examine each factor in more detail.

1. Poor Weather Conditions Can Cause Problems For Spray Foam

The weather plays a vital role in choosing insulation products. After all, we're trying to insulate the outside temperatures from affecting the inside temperatures. A climate with significant temperature swings may have different concerns than a climate with extreme humidity. The environment changes what a building needs from its insulation.

The weather on the day of installation can also influence the success of your spray foam. While spray foam can technically be sprayed year-round, qualified contractors are aware of the limitations and differences weather can introduce. The time of year when spray foam is installed adds a nuance to effective application.

2. Wrong Component Temperatures Can Cause Spray Foam Failure

The chemical reaction that creates spray foam is a science. It's also an exothermic reaction, which means heat is created during the reaction. Manufacturers test temperatures when they develop spray foam components. The contractor must control the heat of the chemicals creating the foam.

If the foam becomes overheated while spraying, it can shrink, char, or burn even if it is on-ratio.

3. Substrate Conditions Can Affect Spray Foam Adhesion

If you spray on-ratio foam, it will make on-ratio foam. But that foam may not have stuck. Sometimes, the condition of the surface that is being sprayed against is not optimal for adhesion. These are conditions that can be changed, but they must be measured by the contractor before application.

Substrate Humidity Must Be Measured

Contactors cannot apply spray foam if there is too much moisture in or on a substrate. As much as 20% moisture in wood would cause serious adhesion problems.

It may have rained the day before the contractors came to spray. Maybe it's been humid in the house. Whatever the reason, the spray foam has a greater chance of failing to adhere in these conditions. A contractor who does not measure for moisture content in relevant climate zones is not a competent contractor.

These substrate conditions also influence spray foam in commercial roofing. You can read about the top problems with spray foam roofing from our friends at GIDEON.

Substrate Temperature Must Be Measured

The temperature of the chemicals matter, but so does the temperature of the substrate. Spray foam can experience tricky adhesion challenges in the cold.

Sometimes, contractors can use different techniques to spray the foam and make it adhere. Other times, the temperature difference may be so drastic that the building needs to be warmed up and dried out. Industrial fans and heaters can be used to raise building temperature and drive out humidity.

4. Climate Zones Can Influence Which Type Of Spray Foam Should Be Used

Open cell foam cannot be used for some types of applications. Generally, this includes concrete and metal. In our climate zone, Climate Zone 5, we usually cannot spray open cell foam against these substrates. For some projects in southern Pennsylvania, closed cell is the only appropriate option due to the substrate.

Open cell is also not a product for anything near or below the ground because it has no vapor barrier. Open cell foam could adhere well if on-ratio but cannot handle high-moisture substrates.

Foam used in the wrong application is a failed foam because it will cause problems for the homeowner.

Can I Prevent Spray Foam Insulation Failure?

The best thing you can do as the owner of your project is to choose your insulation contractor carefully. The main variable in whether or not spray foam will succeed is the expertise of the people installing it. A skilled contractor can prevent many circumstances that lead to adhesion issues and will follow manufacturer guidelines for products.

Sometimes when a contractor is spraying, they will recognize that the foam is not setting and curing as it should. They will notice that something is off with the ratio of the foam. A contractor needs to be educated about how foam should look and feel. The foam could fail if the contractor does not consider these things when spraying.

What Do I Do If I Get Spray Foam Insulation And It Fails?

While spray foam insulation can fail, the likelihood significantly diminishes when working with a skilled contractor. That contractor will know what density and depth of foam to apply, if it should be open or closed cell foam, how to account for humidity, and whether anything is going wrong during the process.

If the spray foam fails against all odds, homeowners are covered. Your contractor should have insurance that will fully cover the replacement of the insulation.

At South Central Services, we ensure our installations are entirely functional. We are aware of the factors that impact adhesion. If any portion of a job would ever fail due to installation or material error, we would remove and replace the foam at no cost to the homeowner.

Now that you understand what causes spray foam to fail, you next step is to:

• Learn how long spray foam insulation should last
• Estimate how much spray foam insulation would cost
• Discover how to evaluate spray foam contractors in your area