In the residential and commercial sectors, there is the common question of Open Cell vs Closed Cell Foam, and which should be chosen for any given project? During this informative article, we will review the differences between Open Cell and Closed Cell polyurethane spray foam in the residential and commercial sectors.
Open Cell vs Closed Cell Foam: Which Should be Chosen?
Are you a developer, home builder, or the general contractor for a commercial property, and are trying to make the determination of which spray foam insulation should be utilized for your project(s)? It’s more difficult than one would think – although closed cell and open cell foam both insulate your designated projects, they perform in different ways. Throughout this guide we will explore the various aspects of both: open cell and closed cell spray foam and assist you in your decision of choosing one, over the other.
What are the differences between Open Cell and Closed Cell Foam Insulation?
Open and Closed cell are two different variations of polyurethane spray foam. They completely different strengths and weaknesses, and neither is particularly superior to the other. It essentially comes down to identifying your particular needs for any given project and utilizing the proper spray foam that would fit your projects unique requirements.
Let us take a moment to identify the differences between open and closed cell foams.
The Cells
Polyurethane spray foam insulation can be referenced as either Open Cell or Closed Cell because of the differences between the small “bubbles” (cells) that comprise the cellular makeup of the foam.
Open Cell foams makeup is comprised of cells that are not completely encapsulated. For example, the cells are deliberately left open. This provides Open Cell with the following properties; it is typically softer and much more flexible material during application.
Closed Cell is as the name suggests, completely comprised of cells that are tightly pressed together, and therefore, air and moisture are unable to penetrate the foams exterior. It is because of closed cell’s inherent properties that it is a much more rigid and stable foam over open cell foam.
Density
Closed cell foam is much denser than open cell foam. Most open cell foam has a density of about .5 pounds per cubic foot. Closed cell foam can be over three times that, with a density of 1.75 pounds per cubic foot or more.
R-Value
R-value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. As a benchmark, one inch of solid wood has an R-value of 1.
Closed Cell foam has a higher R-Value compared to that of Open Cell foam, usually 6.0 per inch. But some closed cell foams, like SVB Conglomerate, Inc’s FOAM-LOK 2000-4G, manufactured by Lapolla have R-Value ratings reaching nearly 7 per inch. This higher rating makes keeping heat in or out of your building envelope. Whereas, Open Cell typically have R-Value ratings around 3.5 per inch. This is significantly lower than Closed Cell foams; which can inhibit the usefulness of open cells functionality in extreme temperature conditions.
Expansion
Arguably the most definitive difference between the two spray foams from an applicators point of view. Closed Cell is manufactured to expand only to roughly 1″ of thickness when applied, but each inch of thickness potentially provides an R-Value of 7, multiple applications can be applied to achieve a higher total R-Values. Alternatively, open cell is designed to expand to 3″ of thickness, meaning that only a single application is possible during typical home installations.
What exactly does all this data mean?
Understandably one could easily be confused by the plethora of information that has been provided here, and you could arguably be no closer to figuring out which of the two foams to utilize for your project. Below you’ll find a summary of open cell vs closed cell foams strengths and the best applications for each:
Benefits of Closed Cell Foam
Closed cell foam is the ideal choice for insulation where the builder/homeowner is concerned about space issues, as it can achieve 2x the R-Value of an open cell inside the standard industry wooden wall studded wall. Additionally, it’s rigid properties provide additional structural integrity to the building envelope and it has passed AC 377 End Configuration Criteria and meets building code requirements for use with no additional ignition barrier required. Lastly, the closed cell provides additional benefits in the form of acting as a vapor barrier; meaning that water and moisture are less likely to gain access to your structure, and the foam itself is likely to be harmed by water damage.
Benefits of Open Cell Foam
One of the most evident benefits of an open cell spray foam is it’s expansion rates after having been applied, meaning it is capable of insulating those hard to reach nooks and crannies in your standard residential or commercial application. These areas can be difficult to insulate with closed cell foam. Additionally, another property not previously discussed is Open Cells soundproofing qualities, and it is typically much less expensive to apply for your project than closed cell.
So Which Insulation Should I Use?
Ultimately, it is dependent on a number of factors: such as your geographic location, the type of furnace used to heat your home, your insulation needs, and of course the budget to be allocated to your project. Need further help deciding which spray foam to utilize in your next project? Don’t hesitate to give us a call and we would be all to glad to assist you in your decision.
