Spray Foam Insulation

WHAT is Spray Foam? What are the benefits?


The pioneering work on polyurethanes was conducted by Otto Bayer and his coworkers in 1937 in Germany. Polyurethane foams, including SPF upholstery (flexibile) foams, etc. were developed in the 1950’s. The Canadians were the first to introduce SPF for construction applications. SPF has been in the U.S. since the late 1960’s as a roofing material. In the early 1970’s, 2 pound/cuft closed-cell foams were introduced for perimeter wall insulation for both the exterior and intertior applications. In the mid 1990’s, 0.5 pound/cuft open-cell foams were brought into the market for interior wall insulation applications.


Spray polyurethane foam, commonly referred to as SPF is a spray-applied insulating foam plastic that is installed as a liquid and then expands many times its original size. Spray polyurethane foam can be adjusted and have many different physical properties depending on the use desired. For example, the same basic raw materials that can make insulation foam semi-rigid and soft to the touch also creates high density roofing foam that is resistant to foot traffic and water. Specialized equipment is used to apply the spray polyurethane foam and proper technical training is important in order to get the best results.

Spray polyurethane foam is the king of building materials for multitasking. For moisture it can provide high levels of R-Value, while providing air barriers and assistance in moister control in buildings. For roofing, spray polyurethane foam insulates and eliminates thermal bridging through fasteners or gaps in decking while providing a long-lasting roofing system that has a life that can be extended by re-coating or recovering in an average of > 10 – 15 years. As a result spray polyurethane foam is used in a wide variety of applications including, but is not limited to:

  • Roofing
  • Air barriers
  • Commercial and residential insulation in walls, ceilings, attics and basements
  • Industrial insulation for pipes and tanks, cold storage facilities, freezers, walk-in coolers, and climate controlled buildings such as produce storage and clean rooms
  • Flotation for boats, ships, barges, floating docks, etc.
  • Higher density spray polyurethane foam has been used to increase the structural strength of wings in airplanes.

So what is spray polyurethane foam?

Spray polyurethane foam is a remarkable versatile material that provides proven solutions to a great range of challenges in the construction and manufacturing industries.

Features and Benefits

What are the benefits of SPF?

SPF is environmentally friendly, contains no formaldehyde or ozone depleting chemicals, saves energy* and reduces the use of fossil fuels, thereby reducing global warming gases. It also assists in providing good indoor air quality, requires less energy to produce than the leading insulation, and reduces the amount of energy required to transport and install it. SPF is durable, maintains physical properties over time, contributes little to the waste stream, and in a single product (depending on the formula and project) can take the place of three-four other products, including insulation, air barriers, sealants, vapor retarders, and weather barriers.

*SPF reduces energy use in the following ways:

  • Has high R-value per inch (open-cell 3.5 per inch and closed-cell 6.0 per inch)
  • Eliminates air infiltration
  • Helps control moisture and condensation
  • Reduces convective currents in walls and attics
  • Eliminates wind washing
  • Effective at low and high temperatures
  • Provides the correct environment so that the ventilation system performs more efficiently

Other benefits include…

  • Closed cell SPF adds structural strength and glues a building together, thereby making it more resistant to racking events, such as hurricanes and high winds.
  • SPF reduces noise from outside by air sealing the building.
  • Closed-cell SPF can provide an added barrier against water intrusion.


SPF reduces drafts and increases comfort.
SPF helps maintain a comfortable, constant, temperature throughout the building, from room to room and floor to floor.


SPF assists in improving indoor air quality.
SPF reduces the infiltration of outside air pollutants and soil gases.
SPF can reduce moisture condensation and mold growth within the building walls and roof.


Excellent insulation efficiency of SPF can reduce heating and cooling usage dramatically.
HVAC equipment can be down-sized, thereby reducing construction costs.
SPF will not sag or settle.
SPF can eliminate the need for separate housewrap and vapor retarders.


SPF helps conserve energy, reducing CO2 emissions.
SPF contributes LEED credits for sustainable, green construction.
SPF can help reduce structural damage caused by high winds.
SPF contains no formaldehyde or ozone depleting substances.

Is Spray Polyurethane Foam Safe?

Yes, cured spray polyurethane foam is relatively inert and studies indicate that SPF does not release toxic gases or leach harmful chemicals into the soil.

Applicators and other persons within a close proximity to the spray operation could be exposed to fumes and spills beyond OSHA and NIOSH requirements. Precautions should be made for applicators, helpers and building occupants to be protected from these fumes, mists and spills. Typically for the applicator this would include respirator, solvent resistant gloves and protective clothing. The zone where protective equipment is required can vary depending on the amount of open space and free ventilation. For example on a roof top, outside of a few feet the fumes dissipate rapidly, while in an enclosed room, fumes and mists can build. Each job should be assessed and a safety plan developed specific to the application.

Where can you find spray polyurethane foam?

SPF is a versatile product that can be used for many things. Rigid polyurethane foams can be used as insulation for buildings, water heaters, refrigerated transport, and other types of commercial and residential refrigeration. SPF has also been used for many years as a high performance roofing system.

Other types of polyurethane foams are used for flotation, packaging, furniture, adhesives, and cavity fillings.

  • Roofing
  • Insulation
  • Roofing Adhesive
  • Construction Adhesive
  • Aerospace
  • Insulation for Spas
  • Foam Packaging
  • Foam Flotation
  • Cavity Filling
  • Mine Shaft Plugging
  • Refrigeration
  • Taxidermy
  • Movie/Theatre sets

Courtesy Spray Polyurethane Foam Alliance, www.sprayfoam.org