open-cell spray foam INSULATION

Protect Your Home From the Elements

What is Open Cell Spray Foam Insulation?

Open-cell spray foam is a polyurethane foam with a low density that provides a better, custom-fit air barrier. When sprayed, the foam expands more than 100 times its original size to fill every nook and hole. Open-cell foam excels in sound absorption, resulting in a peaceful and comfortable indoor atmosphere. Open-cell foam is typically used on above-ground interior walls, ceilings, and the roof’s underside.

Open-cell spray foam is a polyurethane foam with a low density that provides a better, custom-fit air barrier. When sprayed, the foam expands more than 100 times its original size to fill every nook and hole. Open-cell foam excels in sound absorption, resulting in a peaceful and comfortable indoor atmosphere. Open-cell foam is typically used on above-ground interior walls, ceilings, and the roof’s underside.

Adding insulation can help ensure that your building is up to code. Call us today at (360) 265-3905 if you have any questions about foam insulation services.

Benefits of Open Cell Spray Foam Insulation

Spray foam is a polymer that is formed by combining two liquid chemical components in real time during spray application. As a consequence, a foam insulation that can expand up to 100 times its volume before solidifying has been created.

In nature, open-cell spray foam is comparable to closed-cell spray foam. It just has a lower R-value. While most closed-cell spray foams have a density of more than 6.0 per inch, open-cell has a density of 3.6 to 3.8 per inch. Open-cell foam expands as soon as it is applied, making it ideal for hard-to-reach locations. Open-cell foam can readily fill such nooks and crevices.

This form of insulation is popular among homeowners and builders due to its ability to penetrate every nook and crevice of walls and attics. During the wet application procedure, any tight corner, sharp angle, or other impediment may be readily navigated. Spray foam expands and adapts to the space it fills in a couple of minutes. Open cell spray foam insulation, when properly done, dramatically improves the home’s sealed envelope. A superior seal ensures that conditioned air is kept in and seasonal air is kept out.

Types of Open Cell Spray Foam

Spray polyurethane foam (SPF) reduces air leakage better than any other form of insulation.

It is quite straightforward (though not cheap) to entirely fill wall and ceiling spaces with foamed-in-place insulation. Closed-cell spray foam has a higher R-value per inch (6.5) than cheaper insulation materials such as cellulose and fiberglass (3.5 to 3.7).

The majority of spray polyurethane foam is classified as “two-component” foam. Two ingredients, commonly referred to as “A” and “B” components, are blended on-site with specific equipment installed on a trailer or truck. Heated pipes transport the components to a mixing cannon, which sprays the chemicals on the to-be-insulated surfaces.

Open Cell Spray Foam Insulation For Your Home

Let’s get started by explaining what spray foam insulation is in general. It’s a chemical-based insulation that insulation professionals mix on the job site before spraying it in the appropriate place. Typically, spray foam is used to insulate walls, floors, and ceiling voids. Foam insulation does not compress, sag, or settle over time due to its structure, making it an excellent choice for insulating your home. Both open-cell and closed-cell spray foam can endure indefinitely.


As previously stated, open-cell insulation grows more quickly. This results in a more open, bubble-like form. Because of the open structure, this form of insulation is more flexible. Open-cell insulation is also significantly lighter than closed-cell insulation. It is also easy to remove because to its pliability. Furthermore, it may insulate difficult-to-reach areas such as corners, holes, and other forms of niches.


Another advantage of open-cell insulation is that it allows water to pass through it. However, because it is not an organic substance, it does not promote mold development. When the insulation is dry, its efficacy is unaffected. It simply provides a conduit for water and water vapor to go into and out of a specified location.

Open-cell spray foam can retain anywhere from 5% to 70% of its weight in water. If you reside in an area where the humidity is continuously high, open-cell insulation may be less advantageous since it allows external moisture into your home. A vapor retardant can be sprayed over the insulation to assist reduce this issue.


One advantage of open-cell spray foam insulation is that it effectively absorbs sound. This brings us back to the framework. Remember science lessons in elementary school? Sound waves move through the air until they hit something and bounce back. They enter all the little holes inside open-cell spray foam and bounce back and forth until they are absorbed, never reaching your eardrums.


As previously stated, open-cell spray foam insulation has a lower R-value than closed-cell foam. The R-value of open-cell foam ranges from 3.5 to 3.8 per inch. The R-value of a material refers to its ability to resist heat flow. The bigger the value, the stronger the insulating power.


It is also substantially less expensive than closed-cell. Open-cell foam expands almost immediately after application and expands substantially more than closed-cell foam. As a result, you will require less to cover the desired square footage.

Frequently Asked Questions

Is open cell foam insulation worth it?

Open-cell spray foam, the least expensive of the spray foam choices, is utilized in a variety of applications such as roofs, walls, and ceilings. Unlike closed-cell foam, open-cell foam insulation expands significantly during installation and is quite soft to the touch. Open-cell foam is also vapor permeable, which means it does not function as a vapor barrier and must be covered with one. The vapor permeability of open-cell spray foam implies that it can absorb and retain water, which can be dangerous. In the event of a leak, open-cell foam absorbs water and holds it against the frame and sheathing materials, allowing mold and rot to grow.

Which are the pros and cons, open or closed cell spray foam insulation?

The density of each spray foam is proportional to its cell structure. Because open cell foam is softer and more flexible, its core density is smaller. The core density of open cell foam is typically approximately 0.5 pounds per cubic foot. Closed cells, on the other hand, have a considerably higher core density due to the cell shape. Closed cell foam is three to four times heavier than open cell foam, weighing between 1.75 and 2.2 pounds per cubic foot.

When it comes to sound dampening, open cell foam performs far better than closed cell foam due to its lower density. The thicker, softer substance of open cell foam will suppress sound waves considerably more effectively than the tight, compact material of closed cell foam.

Which has more value on expansion and R-value?

Does the fact that open cell foam has a lower density and a larger cell structure imply that it will expand more than closed cell foam? Yes! Because of these factors, open cell foam expands 100 to 120 times its original size, but closed cell foam normally expands about 33 times its original size.

When you consider the expansion, density, and cell structure of each form of spray foam, the appropriate R-Value of each becomes clearer. Closed cell foam has an R-value of 7 per inch sprayed, whereas open cell foam has an R-value of 3.5 to 4 per inch sprayed.

So, based on this, I should choose closed cell spray foam because it has a greater R-Value, right? Not always, of course. The most common cause of heating and cooling loss in a home is improper air leakage management. We can produce an air barrier with closed cell foam at an installed thickness of 1.25′′ using Icynene spray foam. We can also create an air barrier with 3-3.5′′ open cell foam.

Is open cell spray foam insulation more expensive than closed cell spray foam insulation?

The cost of closed cell and open cell foam differs due to their chemical composition and expansion rates. Because closed cell foam is denser than open cell foam, it will require more material to cover the same amount of space, resulting in a higher overall cost. Because more material is being utilized, the labor cost to install it may be higher.

“Protect your home from the elements”

– Pacific Spray Systems

Spray foam insulation is recommended by Pacific Spray Systems for both new construction and upgrades to existing structures. It is especially useful for the latter purpose because, unlike traditional roll insulation, it does not require the removal of any walls or siding to install. If you’re curious about the advantages of spray foam insulation, give our team at Pacific Spray Systems a call.

Without proper insulation in your home or business, you could be losing money on heat loss, water damage and other unnecessary expenses. Turn to a foam insulation contractor to ensure that your property is fully insulated.

Pacific Spray Systems LLC is a preferred choice for spray foam insulation services in Poulsbo, Tacoma, Silverdale and Bremerton, WA. We provide our services to both homeowners and business owners. We use the highest-quality insulation to defend your property against the elements.

Contact us today to talk to a spray foam insulation contractor.


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