Closed Cell Spray Foam | Insulation

Many closed-cell foams have been tested to measure volatile organic compounds. Studies show that within a few hours after application, there are no harmful VOC levels present. Current blowing agents used for closed-cell spray foam, such as Honeywell’s Enovate®, are non-ozone depleting and have low global warming potential.

Spray foam is made using petroleum-based chemicals, which, like many other plastics, require energy to process and transport. Some spray foam manufacturers use soy and sugar based chemicals, and even have some recycled content. While there is some initial environmental impact when making these products, the additional energy saved by closed-cell spray foam quickly offsets the impact from manufacturing and transportation. Current blowing agents used for closed-cell spray foam, such as Honeywell’s Enovate®, are non-ozone depleting and have low global warming potential.

Spray foam requires that the surface to which it is applied be open. Spray foam is a great retrofit product for unfinished areas, such as attics, basements, crawl spaces and band joist. It can also be applied to the building exterior, both above and below grade. Spray foam can be used in existing walls only when the drywall or exterior sheathing are removed. When the wall is enclosed by an interior finish such as drywall, spray foam cannot be used to fill the cavity. Other foam products, such as pour foams, must be used.

No. Closed-cell spray foam must be applied by a trained professional contractor. Small foam installations can be performed using ‘kit’ foams, but this is not an economical approach for large jobs.

As with any product, the installed cost is dependent on prevailing labor rates, as well as the availability of contractors in a specific region. Based on recent RS Means survey data, the national average installed cost for R13 (2”) of closed-cell spray foam insulation is $1.55-2.33/SF. One can compare this to about $0.75/SF for R13 (3.5”) fiberglass batts and $___ for R13 cellulose walls. While more expensive than fibrous insulation, closed-cell spray foam also provides an air barrier, vapor retarder, as well as improved strength and durability. Superior energy savings from closed-cell spray foam can enable reduced framing thickness and downsizing of HVAC equipment. All of these additional benefits should be considered when comparing installed cost of insulation.

Closed-cell spray foam can be applied to virtually any dry surface within the building envelope. It can be used to insulate walls, floors, roofs, crawl spaces, and it is especially useful for insulating hard-to-reach areas.

Closed-cell spray foam meets or exceeds the insulation requirements of the International Code Council’s International Building Code (IBC) International Residential Code (IRC), and the International Energy Conservation Code (IECC), as well as most state and local building codes. Prior to installing spray foam, it is suggested that you work with your contractor and local code officials to confirm that the product you will be using will meet code.

It depends on where your building is located. Generally speaking, colder US climates (IECC Climate Zones 5 and above, and Marine Zone 4) require a vapor retarder with a water vapor permeance of 1 perm or less. When applied to a thickness of about 2”, closed-cell foam meets or exceeds this vapor retarder requirement.

Acoustic performance of building products are measured in two ways: reflectance and transmission. Performance also depends on the frequency of the sound. Closed-cell spray foam is a rigid material and can perform similarly to other insulation materials. Since it provides a superior air-seal, closed-cell foam resists sound transmitted through cracks and gaps in the wall.

Unlike fibrous insulations, closed-cell spray foam does not sag, shift or settle over time. Since it is polyurethane, it forms a permanent and tenacious bond to nearly every material it contacts.

Unlike open-cell spray foam, closed-cell foam does not need to fill the entire cavity to achieve required R-value. As a result, excessive trimming and shaving is not needed, minimizing jobsite waste.

Yes. Closed-cell spray foam has been tested as both a material and as an assembly and meets all requirements established by the Air Barrier Association of America (ABAA).

Since closed-cell spray foam has a high R-value per inch, only 2” is required in a 2x4 wall to achieve R13. This leaves 1.5” of free space between the insulation and drywall to add additional wiring.

Most closed-cell spray foams achieve a Class I fire rating. The can be used in any indoor residential applications provided they are protected by a thermal barrier (like drywall) or an ignition barrier. Please consult your local code official to determine the appropriate protection method and materials.

Closed-cell spray foam must be installed by a trained professional contractor. Spray foam suppliers can provide a list of contractors serving your area.

In addition to conductive energy losses, spray foam forms an airtight seal upon installation. It fills cracks, gaps and holes better than any other cavity insulation, significantly reducing air leakage. Air leaks through the building envelope can account for 20-50% of the energy losses from heating and cooling of a building.