If you need clarification on deciding the ideal type of spray foam insulation for your building, this post explains everything. Spray polyurethane foam (SPF) is a spray-applied insulation material that creates an airtight environment by filling tiny spaces in buildings. Spray polyurethane is a chemical product that expands more than 30 times its original size on application. After expansion, the foam solidifies to reduce air filtration and create an effective thermal barrier.
There are two distinct types of spray polyurethane foam insulation based on their cell structure; closed-cell and open-cell spray foam insulation. Based on its density, spray polyurethane foam is divided into three types. They include high-density, medium-high-density, and low-density spray foam insulation.
This post gives an overview of the differences and essential benefits of closed-cell and open-cell spray foam insulation. A profound understanding of their characteristics and benefits will help you discover the ideal type of spray foam for your next insulation job.
What Is Closed Cell Spray Foam Insulation? (Medium-High Density)
Closed-cell spray foam is a type of spray foam insulation with completely closed cells. They are dense, rigid, and durable. Closed-cell spray foam is subdivided into high-density spray foam and medium-high-density spray foam. The R-value of closed-cell spray foam is between R5.6 and R8, making it suitable for thermally insulating cold climates.
Medium-high-density spray foam offers optimal thermal resistance. They have a density of 2 lbs/ft3 while high-density spray foam has a density of 3 lbs/ft3. The R-value of medium-density spray foam insulation is R5.6 per inch thickness. They are ideal for insulating interior spaces, home wall cavities, and unvented attics.
What Is Open Cell Spray Foam Insulation? (Low Density)
Open-cell spray foam insulation is also known as low-density spray foam insulation. It has an open-cell structure that allows air through these spaces. They are softer, less dense, and more flexible when compared to other types of spray foam insulation. Open-cell spray foam r-value is 3.6 per inch thickness and a density of 0.5 lbs/ft3. Low-density spray foam has better soundproofing abilities but poor moisture resistance. They are also suitable for insulating attics, crawl spaces, walls, etc.
Key Benefits and Differences Between Open-Cell and Closed-Cell Foam Insulation
A proper understanding of the differences and benefits of spray foam insulation is essential before carrying out installation. Both types of spray foam insulation offer excellent insulation, but there are situations where one is more suitable to use than the other. We will highlight key differences and benefits between closed-cell and open-cell foam insulation as we move forward.
How Do the Structural Properties of Open Cell vs. Closed Cell Foam Differ?
Density, rigidity, and cell structure are common structural properties that differentiate both types of spray foam insulation. Open-cell foam insulation has its cells opened while the other possesses completely closed cells that are closely packed together. Thus, open-cell is softer and less rigid than closed-cell spray foam. In terms of density, closed-cell has a higher density than open-cell foam insulation.
What Determines the Density of Open Cell and Closed Cell Foam?
The cell structure of spray foam determines its density. The absence of tiny spaces or bubbles in closed-cell spray foam makes it dense and rigid. In contrast, the presence of bubbles and tiny spaces in open-cell spray foam makes it soft and less dense.
Why Does the Cell Structure Matter in Spray Foam Insulation?
Spray foam insulation is classified based on its cell structure. The cell structure of both types of spray foam insulation determines insulating capabilities, water resistance, and permeability. In addition, the cell structure of foam insulation determines the insulating material’s ability to absorb sound.
Open-cell spray foam insulation is porous and permeable. The cell structure of open-cell spray foam makes it permeable to air and water vapor. The breathable cell structure of open-cell provides excellent sound-absorbent capabilities.
Closed-cell spray foam has tightly packed cells. This makes it rigid and stronger than open-cell spray foam. They are almost impermeable, making them highly resistant to air filtration and moisture. However, closed-cell spray foam provides poor soundproofing capabilities.
Which Offers Better Thermal Insulation: Open Cell or Closed Cell Foam?
Closed-cell spray insulation offers better thermal insulation than open-cell. Thermal insulation of material is measured by its R-value. Consequently, a higher R-value means superior thermal insulation.
How Does the R-Value Compare Between Open Cell and Closed Cell Foam?
Closed-cell spray foam R-value is within the range of R5.6 to R8 per inch thickness. On the other hand, open-cell spray foam R-value averages around R3.6 per inch thickness.
Closed-cell spray foam is suitable for places that require a high R-value. Due to its thickness, closed-cell is used to achieve a high recommended thickness. Installing a minimum recommended R-value of r24 requires applying 4 inches of an r8 closed-cell spray foam spray.
In contrast, applying 7 inches of an r3.5 open-cell spray foam product will achieve the same minimum recommended R-value of r24. Open-cell spray foam should be used for places with moderate temperatures or low recommended R-value.
How Effective Is Air Sealing with Open Cell vs. Closed Cell Foam Insulation?
The air-sealing capabilities of open-cell and closed-cell foam insulation are highly effective. They help to reduce air filtration, drafts, and heat loss in buildings significantly. Nevertheless, between the two types of spray foam insulation, closed-cell spray foam provides more effective air-sealing capabilities than open-cell spray foam insulation. This is due to the impermeability and dense structure of closed-cell spray foam.
How Does the Cost of Open Cell vs. Closed Cell Spray Foam Insulation Compare?
Spray foam insulation cost is relatively expensive compared to other types of insulation. In the United States, spray foam insulation cost per sq foot is $1.5 to $4, depending on the type of foam insulation used. According to prices on This Old House, spray foam insulation price costs between $2,750 - $6,500 for a 1000 sq footage job in a new home.
What Are the Costs Associated with Closed Cell Foam Insulation?
Two major costs are associated with installing cost-cell foam insulation. They include labor costs and material costs. Material costs can include spraying guns, protective gear, spray foam products, and spray foam nozzles. Hiring a professional contractor is more expensive than carrying out DIY spray foam insulation. Labor costs go as much as $3000 for installing closed-cell spray foam.
Several other factors can influence closed-cell spray foam costs. These factors include the thickness of foam applied, job complexity, brand, and application size.
How Does the Cost of Open Cell Foam Insulation Compare to Closed Cell?
Generally, closed-cell spray foam is more expensive than open-cell spray foam. The average cost of installing closed-cell spray foam per square foot in the United States is between $1.5 to $3.
Open-cell spray foam insulation costs between $0.5 to $1.5 per square foot. Using a spray foam insulation cost calculator for a 1000 sq footage job, open-cell spray costs between $500 to $1500.
What is the Recommended Thickness of Open Cell and Closed Cell Foam?
The recommended thickness for spray foam depends on where it is applied. Different areas have their recommended thickness to effectively create an air seal. The aim of having a recommended spray foam insulation thickness is to create an air seal. Increasing the R-value by adding more foam is just a total waste of money.
The recommended thickness for open-cell spray foam is 6 to 10 inches for roofs or ceilings. For wall insulation, a recommended thickness of 3 inches is enough to create an air seal.
The recommended closed cell spray foam thickness is less than open-cell spray foam because it is dense and more rigid. Closed-cell spray foam will require fewer inches of spray foam thickness to achieve the same R-value as open-cell spray foam. The recommended closed-cell spray foam thickness is 4 to 5 inches for ceilings, while walls should be 2 to 3 inches thick.
Can Open Cell or Closed Cell Foam Provide Better Sound Insulation?
Open-cell spray foam insulation offers better sound insulation than closed-cell spray foam. The cell structure of open-cell spray foam allows sound waves to be absorbed and reduces noise transmission in buildings. Open-cell spray foam is used for soundproofing rooms and buildings. Closed-cell spray foam also reduces noise transmission between walls and ceilings because of its rigid structure. Both types of foam have their specific advantages in terms of sound insulation, with open-cell foam excelling in mid/high frequency sound absorption and closed-cell foam offering superior blockage of low frequency sounds.
Which Is More Resistant to Moisture and Water: Open Cell or Closed Cell Insulation?
Closed-cell insulation retards moisture better than open-cell insulation. They act as a vapor barrier in buildings to reduce moisture problems such as mold growth and mildew. Creating a waterproof environment helps to maintain the effectiveness of your foam insulation.
Closed-cell insulation is the most suitable type of spray foam for insulating flood areas, basements, and crawl spaces.
Open-cell spray foam insulation offers poor moisture resistance because of its permeable structure. It allows water to flow easily if it's an open structure. Open-cell spray foam is not suitable for areas prone to flooding or moisture.
What Should You Know About the Installation Process of Open-Cell vs. Closed-Cell Foam?
The installation process of open-cell and closed-cell foam differ as their expansion rates are different. The curing time is another important aspect of the installation process. Curing is the process of allowing a material to attain optimal strength. It is the process where foam insulation solidifies.
Open-cell spray foam has a higher expansion rate than closed-cell foam insulation. When applied, open-cell spray foam expands up to 3 inches in thickness. The expansion rates make them suitable for fast one-time applications. However, open-cell spray foam has a slower curing time than closed-cell spray foam insulation.
Closed-cell spray foam insulation has a low expansion rate. It expands to about 1-inch thickness when applied. This means for every application of closed-cell spray foam, the R-value of the foam product is achieved. Therefore, when an R6 spray foam product is sprayed, 1-inch thickness and an R-value of R6 are achieved.
Where Should You Apply Open Cell and Closed Cell Foam for Optimal Performance?
Choosing the area of application for optimal performance is dependent on several factors. The predominant factors are location, insulation goals, and budget costs.
Closed-cell spray foam is suitable for areas prone to flooding and cold climates. They have superior moisture resistance to prevent mold growth in buildings. In addition, they help to prevent heat loss in buildings during winter.
Open-cell spray foam is suitable for indoor insulation and soundproofing. They are not suitable for areas prone to flooding or moisture. Open-cell spray foam is less expensive and budget-friendly.
Is Open Cell or Closed Cell Foam More Cost-Effective In The Long Run?
The cost of installing open-cell is cheaper than closed-cell spray foam. The cost per square foot of open-cell spray foam is also less expensive. However, achieving a recommended thickness using open-cell spray foam will require more insulation layers, which is not cost-effective in the long run.
In essence, achieving a recommended R-value of R30 is cheaper with closed-cell spray foam than with open-cell. Closed-cell spray foam is dense, rigid, and offers a higher R-value. In addition, closed-cell spray foam offers better thermal insulation and durability. This helps to save energy costs and provide comfort in your home for a longer period.
Which Type Of Spray Foam Insulation Is More Environmentally Friendly?
Generally, open-cell is considered more eco-friendly spray foam insulation than closed-cell. Closed-cell spray foam is argued to have more environmental impact due to the presence of blowing agents with high GWP.
Over the years, there have been advancements to reduce the GWP of spray foam products significantly. The Sprayman Thermal Insulation stands out as the best eco-friendly product in the market.
Open Cell Vs. Closed Cell: Which Is More Durable And Has A Longer Lifespan?
Open-cell and closed-cell foam insulation are both durable with long lifespans. However, closed-cell spray foam provides more durability and longer lifespan than open-cell foam insulation. Closed-cell spray foam can last up to a lifetime without replacement. They are not prone to moisture problems that can have long-term effects on spray foam insulation. On the other hand, open-cell spray foam does not do well when installed in a damp environment. Moisture reduces the durability and lifespan of open-cell foam insulation.
Conclusion
In a nutshell, the decision between choosing closed-cell vs open-cell is dependent on several factors. These factors include installation cost, goal, and location. The two types of spray foam insulation have certain benefits over one another.
Closed-cell spray foam insulation is dense and provides better thermal insulation than open-cell. They are commonly used in insulating buildings in cold locations. Closed-cell spray foam insulation offers better moisture resistance, durability, and structural support in buildings. They reduce the risk of having moisture problems in buildings.
In terms of installation cost, open-cell foam insulation is a cheaper option than closed-cell spray foam. In addition, they provide better soundproofing capabilities. Open-cell offers a faster expansion rate than closed-rate. They expand up to 100 times their original size, while closed-cell insulation expands up to 30 times. This makes open-cell spray foam a suitable option for insulating tight areas.
Open Cell vs. Closed Cell Spray Foam Insulation
|
Density |
2 lbs/ft3 |
3 lbs/ft3 |
|
R-value |
R3.6 |
R5.6 to R8 |
|
Air sealing |
Optimal air sealing abilities |
Excellent Air sealing abilities |
|
Cost (per sq foot) |
$0.5 - $1.5 |
$1.5 -$3 |
|
Recommend Thickness |
6 - 10 inches |
4 - 5 inches |
|
Sound Insulation |
Absorbs Mid/High Frequencies |
Blocks Low Frequencies |
|
Moisture and Water Resistance |
Poor water resistance |
Excellent moisture resistance and vapor barrier |
|
Installation Process |
Fast expansion rate & slow curing time |
Slow expansion rate & quick curing time |
|
Cost- Effectiveness |
Lower Initial Cost, Higher Volume Required for Equivalent R-Value |
Higher Initial Cost, Lower Long-term Energy Costs |
|
Environmental Friendliness |
Eco-friendly |
Eco-friendly |
|
Durability and Lifespan |
Durable |
Durable |