When planning a barndominium or pre-engineered metal building, insulation is one of the most important decisions you’ll make. The right insulation impacts energy efficiency, comfort, durability, and long-term operating costs. Two of the most common options are open cell and closed cell (often called “cold cell”) spray foam.
While both are spray-applied foam insulations, they perform very differently. Understanding those differences helps ensure your building is insulated the right way from day one.
What Is Open Cell Spray Foam?
Open cell spray foam is a lighter, less dense insulation with a sponge-like structure. The foam expands significantly when applied, filling cracks, seams, and hard-to-reach areas.
Key characteristics of open cell foam:
-
Lower density and softer texture
-
Expands more, allowing it to fill large cavities easily
-
Lower cost per square foot
-
Provides good air sealing
-
Allows some moisture permeability
Open cell foam is commonly used in conditioned residential spaces where sound dampening and air sealing are priorities. Because it’s breathable, it allows moisture to pass through rather than trapping it—something that can be beneficial in certain interior applications.
What Is Closed Cell (Cold Cell) Spray Foam?
Closed cell, often referred to as “cold cell,” is much denser and more rigid than open cell foam. Its tightly packed cell structure creates a powerful thermal barrier and adds structural strength to the building.
Key characteristics of closed cell foam:
-
High density and rigid once cured
-
Higher R-value per inch
-
Acts as an air barrier and vapor barrier
-
Adds strength to walls and roof systems
-
More resistant to moisture intrusion
Closed cell foam is frequently used in metal buildings and barndominiums where temperature control, moisture management, and long-term durability are critical.
R-Value: The Performance Difference
One of the biggest differences between the two comes down to R-value, which measures insulation’s resistance to heat flow.
That higher R-value means closed cell insulation provides more thermal resistance in less space—making it especially effective in metal buildings where controlling heat transfer is a top priority.
Moisture Control Matters in Metal Buildings
Moisture management is often the deciding factor between open cell and closed cell insulation—especially in pre-engineered metal buildings.
Open cell foam allows moisture to move through it, which can be acceptable in certain interior wall applications. However, in metal structures, moisture control is critical to prevent condensation, corrosion, and long-term damage.
Closed cell foam forms a vapor barrier, helping protect steel components from moisture-related issues. This added protection can significantly extend the life of the building.
Cost vs. Long-Term Value
Open cell insulation generally costs less upfront, which makes it appealing for budget-conscious builds. However, closed cell insulation often delivers greater long-term value due to:
-
Higher energy efficiency
-
Improved moisture resistance
-
Added structural strength
-
Reduced maintenance concerns over time
Choosing insulation isn’t just about initial cost—it’s about how the building performs year after year.
Which Insulation Is Right for Your Building?
There is no one-size-fits-all answer. The right insulation depends on:
For many barndominiums and metal buildings, closed cell insulation is often the preferred solution. In other cases, a combination of insulation types may be the most effective approach.
