One of the most common concerns when considering insulation options for your home is how well the insulation will hold up to water exposure.

Whether it’s from a flood, a leaky pipe, or just high humidity, homeowners understandably want to know: Does foam insulation, both spray and injection foam, absorb water after getting wet? These are important questions, and today, we’re diving into the answers.

The Big Question: Does Spray Foam Absorb Water?

Let’s get right to the heart of it – does spray foam absorb water?

The short answer is no, spray foam does not absorb water. Whether you’re using closed cell spray foam or RetroFoam injection foam, these products are designed to resist water intrusion rather than soak it up like a sponge.

In fact, one of the key advantages of spray foam insulation is its ability to provide an effective moisture barrier, protecting your home from the elements.

Understanding How Spray Foam Works

Spray foam insulation, particularly closed cell foam, creates a tight seal wherever it is applied.

This seal is impermeable, which means it does not allow water to pass through. Closed cell spray foam, in particular, is often touted for its ability to resist water and even act as a vapor barrier in certain applications.

On the other hand, open cell spray foam and RetroFoam insulation are more permeable, which means they allow water vapor to pass through but still do not retain liquid water. This can be advantageous in certain scenarios where you want your walls to “breathe,” allowing moisture to escape rather than being trapped inside.

What Happens if Spray Foam Gets Wet?

So, what happens if spray foam gets wet?

This is where the conversation gets a little more nuanced. If water comes into contact with cured spray or injection foam, it will not absorb the water. Instead, the water will usually flow through it or around it if there are any gaps.

But what if there’s a flood or significant leak?

In cases of severe water intrusion, such as a burst pipe or a flood, water will exert pressure on the foam. This pressure can cause the foam to break apart, allowing the water to flow through it.

However, the foam itself does not absorb water – instead, it may be damaged or displaced by the force of the water.

Is Foam Waterproof?

Another popular question is whether foam insulation is waterproof.

Closed cell spray foam is water-resistant, meaning it won’t absorb moisture, and it can help protect your home from water damage by creating a barrier. However, it’s essential to understand that no insulation material is completely waterproof.

Closed cell spray foam is close to it, but if water manages to get through the foam barrier – whether due to improper installation, damage, or extreme conditions – the insulation can become compromised.

In contrast, open cell spray foam is not considered to be waterproof.

While it doesn’t retain water, it also doesn’t block it, which is why open cell foam is typically used in areas where moisture resistance isn’t the primary concern.

The same is true for RetroFoam injection foam.

Can Spray Foam Stop Water?

Given its moisture-resistant properties, you might wonder if spray foam can stop water entirely.

The answer is yes, but only under certain conditions.

Closed cell spray foam can act as an effective moisture barrier, preventing water from entering the space it insulates. This is particularly useful in basements, crawl spaces, and other areas prone to moisture.

However, it’s crucial to note that while spray foam can stop water, it is not a substitute for proper waterproofing techniques. If your home has significant moisture issues, such as a high water table or poor drainage, additional waterproofing measures will be necessary to ensure it stays dry.

We always recommend that any existing water or moisture issues should be addressed before adding spray foam insulation.

Can Foam Insulation Get Wet?

The final question we’ll tackle is whether foam insulation can get wet and still function properly.

If we’re talking about closed cell spray foam, the answer is yes. Because it doesn’t absorb moisture, closed cell spray foam can get wet without losing its insulating properties. Once the water is removed, the foam will continue to perform as expected.

While open cell spray foam does not retain water, it may lose some of its insulating properties if exposed to water for prolonged periods. Since it allows moisture to pass through, open cell foam could lead to moisture-related issues like mold or mildew if it becomes wet and is not allowed to dry out properly.

What About RetroFoam Insulation?

RetroFoam, an injection foam designed to insulate existing walls, also has impressive water-resistant properties.

Like other foam insulation products, RetroFoam does not absorb water. RetroFoam creates a continuous barrier that helps keep moisture out when properly installed in an enclosed space.

In the event of a significant leak or flood, RetroFoam behaves similarly to superior spray foam products – it doesn’t absorb water. Still, it may break apart under pressure from water intrusion. If water manages to get into the wall cavity where RetroFoam is installed, the foam could be damaged, allowing water to pass through.

This isn’t necessarily a bad thing. RetroFoam can break apart under pressure, allowing water to escape potentially preventing more severe water damage to the home's structure.

The Importance of Proper Installation

Proper installation is one of the most critical factors in ensuring that your spray foam and injection foam insulation performs well in wet conditions.

Foam insulation must be applied correctly to create a continuous barrier against moisture. Any gaps, cracks, or improperly sealed areas can compromise the insulation’s effectiveness and leave your home vulnerable to water damage.

It’s also essential to consider your home's overall construction and waterproofing. While foam provides an excellent line of defense against moisture, it should be a piece to a bigger puzzle of a comprehensive moisture management strategy that includes proper drainage, gutter systems, and, where necessary, additional waterproofing techniques.

What Homeowners Need to KNow to Keep Their Homes Dry

Understanding how foam insulation interacts with moisture is key to protecting your home from water damage.

Here’s a quick recap.

• Does foam insulation absorb water? No, premium spray and injection foam do not absorb water. They resist moisture, making them an excellent choice for areas prone to humidity or minor water exposure.

• Is foam waterproof? Closed cell spray foam is water-resistant and can act as a moisture barrier. Open cell spray foam and RetroFoam injection foam are not waterproof but still do not absorb water.

• Will spray foam stop water? Yes, closed cell spray foam can stop water from entering your home when properly installed. However, it is not a substitute for comprehensive waterproofing.
  
  
• Can spray foam get wet? Yes, spray foam can get wet. Closed cell foam will continue to perform after drying out, but open cell might lose some effectiveness if exposed to prolonged moisture.

• Can foam insulation get wet? Yes, it can get wet without absorbing water. However, water pressure can damage the foam, potentially compromising its insulating properties.

For homeowners, the bottom line is that foam insulation, particularly closed cell spray foam, offers excellent protection against moisture but should be part of a broader strategy for managing water and preventing damage.

Whether you’re dealing with high humidity, minor leaks, or the possibility of a more severe water event, foam insulation can help keep your home dry, comfortable, and energy-efficient.

If you have more questions or want to explore the topic further, be sure to visit our Learning Center. There, you will find a wealth of information on foam insulation, building science, and how to protect your home from the elements.

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