What Is the Difference Between Closed and Open Cell Foam Insulation Types?

Homeowners and business owners in Mississauga can opt to have spray foam insulation in their homes or offices.  There are two types to choose from, each with its own use and benefits. Closed cell foam is the stronger of the two, and has exterior use as well as interior. This doesn’t mean, however, that it is always better than the open cell variety, as the latter has its uses as well.

What are the differences between the two? What benefits do each offer?

Open Cell Foam

This type of spray foam insulation is less costly, although it offers a lower R-value. Water is used as the blowing agent, which forms carbon dioxide when reacting with air. The carbon dioxide expands quickly, causing bubbles to burst. Atmospheric air fills the spaces within the cells, making the foam similar to a sponge. This means that open cell foam is not resistant to humidity.

Open cell foam is not as dense as closed cell foams. It has its place in hot, humid climates as well as in air conditioned attics, where water vapor trapped between roof sheathing and insulation could potentially cause wood rot. The structure of the open cells allows vapor to pass through, providing an air barrier. The holes in the cells allow for them to interconnect.

One place where homeowners would NOT want to the open cell variety below grade are in areas where it could absorb water, as this would negate its thermal capabilities. Its typical R-value at one-inch is less than 5.

Benefits of Open Cell Foam

  • While it does not act as a vapor barrier, it does provide vapor permeability. Its permeability enables bi-directional drying of assemblies, thus allowing bulk water to pass through.
  • Even though it offers a lower R-value than its closed cell counterpart, open cell foam insulation does maintain its R-value for a lifetime.
  • Despite its softness, it is both a consistent and flexible material, and retains its air seal throughout every season.
  • It’s a mold resistant material.
  • It offers superior sound absorption when compared to closed cell foam.

Closed Cell Foam

With this type of foam spray insulation, the bubbles are closed and keep the gas bubbles that are formed during the expansion trapped within. The liquid chemical blowing agent is permanently locked into place during the curing process. While the gas expands as it is applied, it does so at a slower rate than CO2. This allows the material to set before the bubbles burst open.

In order for the gas bubbles to be trapped, the cured foam must be of at least a medium density and strong. Even though it costs more than the open cell variety, closed cell foam has use in more places, including the exterior of a building. Its typical R-Value is 6 to 6.5 per inch.

Benefits of Closed Cell Foam

  • It has rigid consistency, which provides wall racking strength and impact resistance.
  • Not only is it able to deflect water, it’s also able to reject bulk water.
  • It helps to prevent air leakage, which relieves the load on cooling and heating systems.
  • The cost associated with the initial investment pays for itself overtime with energy-efficiency.

Residents can consult with Home Insulation specialists to learn more about their Spray Foam Insulation Mississauga options. You can reach us at (905)761-0844