What is Spray Foam Insulation?
Spray foam insulation (SPF), or spray polyurethane foam, is one of the most energy-efficient and cost-effective solutions for residential and commercial buildings. Whether you’re working with new construction or upgrading an existing structure — from metal buildings to barns — spray foam helps your building perform as a complete system. When applied to walls, roofs, ceilings, floors, basements, and foundations, it minimizes air leaks and keeps conditioned air inside where it belongs. SPF is a powerful 2-in-1 solution, serving as both a high-performance insulator and a superior air barrier.
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Why Spray Foam Insulation?
Understanding R-Values
R-value measures how well a material resists heat transfer. It reflects the thermal resistance of insulation — the higher the R-value, the better its insulating performance. Keep in mind, actual effectiveness can vary depending on the type of construction and the heating or cooling system in place.
Click here to see recommended Home Insulation R-Values
Common Air Leaks vs a Sealed House
Up to 40% of a building’s energy is lost through air leaks, driving up utility costs. Spray foam acts as both insulation and an air barrier, sealing gaps and reducing energy waste. The EPA estimates that heating and cooling account for nearly half of a home’s energy use. By improving efficiency, spray foam can reduce HVAC sizing by up to 35%.
Spray foam effectively seals common leak areas such as attic hatches, knee walls, wiring holes, plumbing vents, recessed lights, rim joists, and around windows and doors.
Spray foam can also enhance “cool roof” performance when topped with a reflective coating. These roofs reflect sunlight, stay cooler, and reduce heat gain—without the need for metal fasteners that create thermal bridges.
Adapted from WhySprayFoam.org’s publication entitled “Why Choose Spray Foam?” – Downloadable here: https://www.whysprayfoam.org/wp-content/uploads/2021/09/Why-Choose-Spray-Foam.pdf
Spray Foam Insulation Information:
Spray foam insulation is an alternative to traditional building insulation, such as fiberglass. It is a two-component mixture composed of isocyanate and polyol resin that come together at the tip of a gun and forms an expanding foam. The foam can be sprayed onto roof tiles, concrete slabs, into wall cavities, or through holes drilled into the cavity of a finished wall. Both types of SPF are thermoset cellular plastics comprising millions of small cells. There are two different types of spray foam insulation:
Light-Density Open Cell (half pound foam):
- Due to its ability to expand during the application process, OC SPF fills cracks, crevices, and voids and adheres to irregular surfaces or substrates to form an air sealing insulation.
- It provides sound reduction by blocking and absorbing air leakage.
- Reduces noise transmission.
- Semi-rigid material with a sponge-like appearance that expands during installation and creates small, open cells that are filled with carbon dioxide. It can be crushed in your hand.
- It is less expensive than traditional types of insulation such as fiberglass.
- OC SPF has a typical R-value of 3.5 to 3.7 per inch.
- It is usually only recommended for indoor applications.
- We normally do not recommend using open cell foam in the Pacific Northwest.
Closed Cell (aka two-pound foam):
- CC SPF creates an airtight barrier. When the required minimum thickness of 1.5-2 inches is installed, CC SPF is both a vapor barrier and an air barrier.
- It is perfect for attics, exterior walls, and metal buildings.
- Reduces noise transmission.
- A moisture barrier is created.
- It is rigid to the touch
- Adds strength and rigidity for improved structural integrity.
- There is a typical R-value of 6 per inch.