Closed-Cell Foam Versus Open-Cell Foam

Choosing the Right Foam for Your Project

Need new insulation? Are you considering adding spray foam to your attic? Perhaps you want to soundproof a room. Maybe you want to upgrade the insulation in your crawlspace. There are many insulation projects that can be done around the home, so you are probably wondering what the correct spray foam is for your specific needs. There are two types of polyurethane spray foam, Closed-cell, and open-cell. It is important to understand the differences, as each foam has its own set of ideal applications. So let’s take a deeper dive into closed versus open-cell spray foam.

Closed-Cell Foam

Closed-cell foam is highly dense. When it is sprayed, it will expand up to 30 times its original liquid volume. In closed-cell spray foam, cells or bubbles in the foam are compacted together, are not broken and each is filled with an inert gas selected to make the insulation value of the foam as high as possible. Generally, the R-value of this type of foam is 6.4+ per inch. Closed-cell for is not water permeable. The ideal applications for closed-cell foam include:

• Coastal areas
• Below-grade areas
• Crawlspaces and crawlspace encapsulation
• Whole house application
• Basements and basement encapsulation
• Areas that are windy, damp, and water-prone

Example of closed-cell application in a pole barn

Open-Cell Foam

Open-cell foam is soft. Imagine it similar to a foam pillow or cushion. This type of insulation makes a great air and sound insulator. When it is sprayed, it will expand up to 150 times its original liquid volume. This makes it perfect for filling nooks and crannies in a wall cavity. Open-cell foam has an R-value of 3.7+ per square inch and is water permeable. The ideal applications for open-cell foam include:

• Attics
• Direct application to walls
• Soundproofing media rooms or workspaces
• Roof decks

Great for media rooms

Questions? Consult the Spray Foam Experts at Foam All

Now that you know the basics about the two types of polyurethane spray foam, you may still want to know more about your own project for your home. That is why we are here! At Foam All, we revolve around everything spray foam. We are here to answer your questions and determine the right course of action. Feel free to call us at (586) 770-9171. Our team cares about you, and your home. Your project is our top priority!

To see our team in action, and examples of our work, we hope you will visit our YouTube channel or Facebook page. If you would like answers to additional frequently asked questions, visit our FAQ page. We look forward to hearing from you!

Why Closed-Cell Spray Foam Is One of the Best Defenses Against Mold & Mildew

Moisture is one of the most damaging forces a home or commercial building can face. Left unchecked, it can lead to mold growth, structural deterioration, and serious indoor air quality issues. One of the most effective ways to combat moisture intrusion is through closed-cell spray foam insulation, a high-performance solution designed to seal, protect, and strengthen your property.

What is Closed-Cell Spray Foam?

Closed-cell spray foam is a high-density polyurethane insulation that expands on contact, filling gaps, seams, and cracks. Unlike open-cell foam, this material forms a rigid structure with sealed cells that do not absorb water. The result is a durable insulation layer that acts as both a thermal barrier and a moisture-resistant shield.

Because it resists water infiltration and limits air movement, this type of insulation is especially effective in environments where humidity, condensation, or groundwater exposure is a concern.

How This Insulation Protects Against Water Damage

One of the defining advantages of closed-cell foam is its ability to create a continuous, airtight seal. When applied to walls, roofs, foundations, or subfloors, it forms a protective barrier that limits water intrusion and reduces the pathways moisture uses to enter a structure.

By blocking air leaks and preventing moisture migration, this sealed-cell insulation helps protect buildings during heavy rain, snow melt, and high-humidity conditions—reducing the risk of long-term water damage and costly repairs.

Stopping Mold and Mildew Before They Start

Mold and mildew require moisture to grow. When damp air or water infiltrates walls, ceilings, or flooring systems, it creates the ideal environment for spores to spread.

High-density spray foam insulation helps eliminate this risk by:

• Preventing moisture from entering wall and ceiling cavities
• Reducing condensation caused by temperature differences
• Maintaining a drier, more stable indoor environment

By removing the conditions mold needs to thrive, this insulation method supports healthier indoor air quality and long-term property protection.

Common Applications for Moisture-Resistant Spray Foam

This type of insulation is widely used in both residential and commercial settings where moisture control is critical:

• Basements & Crawl Spaces: Below-grade areas are especially vulnerable to damp conditions. A rigid foam barrier helps protect foundations and reduce humidity levels. Closed-cell foam provides a waterproof barrier that protects your foundation and keeps your basement dry.
• Attics & Roofs: Condensation and roof leaks can lead to hidden moisture problems. Spray-applied insulation helps seal vulnerable areas and improve overall thermal performance.
• Concrete Floors and Slabs: Concrete is porous by nature. Applying a moisture-resistant insulation layer helps prevent water vapor from migrating upward into finished spaces.
• Commercial Buildings: Warehouses, offices, and retail spaces benefit from improved humidity control, energy efficiency, and long-term durability.

Additional Benefits Beyond Moisture Protection

While moisture control is a major advantage, closed-cell spray foam offers several additional benefits:

• Improved Energy Efficiency: By sealing air leaks, this insulation reduces heating and cooling loss and helps lower energy costs.
• Added Structural Strength: The rigid nature of the foam reinforces walls and roof assemblies, increasing durability.
• Long-Term Performance: Unlike traditional insulation materials, it does not sag, settle, or degrade over time.

Why Choose Foam All for Spray Foam Insulation?

At Foam All, we specialize in professional spray foam insulation solutions for residential and commercial properties. Our experienced team understands how to apply moisture-resistant insulation systems correctly, ensuring long-lasting protection and performance.

Whether you’re addressing a damp basement, protecting a commercial structure, or preventing mold before it becomes a problem, we tailor every application to the needs of your property.

Protect Your Property from Moisture and Mold

When it comes to defending your building against water damage, mold, and mildew, closed-cell spray foam insulation remains one of the most reliable solutions available. Its ability to seal, insulate, and protect makes it a smart investment for long-term peace of mind.

Ready to safeguard your home or business? Contact Foam All today to schedule a consultation or request an estimate. Be sure to follow us on Facebook to see our latest projects and updates.

Why Foam All Spray Insulation Chooses Closed-Cell Spray Foam for Lasting Performance

When it comes to insulation, not all foam is created equal. At Foam All Spray Insulation, we believe in providing the highest quality results for every project—whether it’s a new home, a renovation, or a commercial build. That’s why our team relies on closed-cell spray foam insulation for most applications. This advanced material offers exceptional energy efficiency, durability, and protection, making it the ideal choice for long-term comfort and performance.

What Is Closed-Cell Spray Foam?

Closed-cell foam is a type of polyurethane foam that expands on application, filling gaps, cracks, and cavities to create an airtight barrier. The term “closed-cell” refers to the foam’s dense, tightly packed structure—each microscopic cell is completely sealed off from the next. This unique composition makes closed-cell foam more rigid, durable, and resistant to moisture than its open-cell counterpart.

Why Closed-Cell Foam Is the Right Choice

Superior Insulating Power (High R-Value)

Closed-cell spray foam offers one of the highest R-values per inch of any insulation material—typically around R-6.0 to R-7.0 per inch. This means it delivers excellent thermal resistance in a thinner layer, making it perfect for tight spaces or areas where energy efficiency is a top priority.

Exceptional Moisture Resistance

Unlike open-cell foam, closed-cell spray foam acts as both an insulator and a moisture barrier. Its dense structure prevents water absorption, helping to protect against mold, mildew, and long-term structural damage—especially valuable in basements, crawl spaces, and exterior walls.

Added Structural Strength

Once cured, closed-cell foam hardens into a rigid material that adds strength to walls, roofs, and other building surfaces. This added rigidity helps improve overall structural integrity, which is an advantage for both residential and commercial applications.

Air Sealing and Energy Efficiency

Because it expands to fill every gap and seam, closed-cell spray foam provides a complete air seal, reducing drafts and heat loss. This airtight seal minimizes energy waste and helps HVAC systems run more efficiently, lowering monthly utility bills.

Longevity and Durability

Closed-cell spray foam doesn’t sag, settle, or deteriorate over time. Once installed, it continues to perform year after year, providing reliable insulation and protection with minimal maintenance.

Benefits for Residential and Commercial Projects

Closed-cell foam offers unmatched versatility—it’s suitable for a wide range of projects and building types.

• Residential Homes: Keeps homes comfortable year-round, reduces energy costs, and improves indoor air quality.
• Commercial Buildings: Helps maintain consistent interior temperatures and reduces heating and cooling loads in larger structures.
• Agricultural or Metal Buildings: Provides both insulation and condensation control, protecting valuable equipment and stored materials.

Trust Foam All Spray Insulation for Quality and Performance

At Foam All Spray Insulation, we take pride in using only the best materials and techniques to deliver superior insulation solutions. Our use of closed-cell spray foam ensures your property stays comfortable, efficient, and protected for years to come. Whether you’re insulating a new construction project or upgrading an existing building, our experienced team can help you choose the right insulation system for your needs.

Ready to experience the difference of closed-cell foam?

Contact Foam All Spray Insulation today to schedule your consultation or request a free quote!