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.
SPF 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, SPF 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 more than 10 to 15 years. As a result, SPF 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 SPF has been used to increase the structural strength of wings in airplanes.
Spray foam provides insulation and air sealing benefits that can help strengthen buildings and make them more durable during the upcoming hurricane season, Spray Foam Coalition notes. While SPF's insulation and air sealing benefits are well known, many building owners may be unaware of its other properties that can help strengthen buildings and make them more durable. Closed-cell spray foam can improve a building’s strength and durability in several ways. When applied to the interior side of a roof, closed-cell SPF can increase a building’s resistance to wind uplift during severe storms. Studies have found that applying closed-cell SPF under a roof deck provides up to three times the resistance to wind uplift for wood roof sheathing panels compared to a conventionally fastened roof. Studies have also shown that applying closed-cell SPF to wall cavities can increase racking strength (i.e., resistance to horizontal forces like high winds) versus those without SPF. Closed-cell SPF itself can also resist water damage. The material can be cleaned and dried, which is why the Federal Emergency Management Agency (FEMA) has classified closed-cell SPF as an insulation material that can resist flood damage. Using SPF can provide better moisture control to help resist the formation of mold in walls, and under floors and ceilings. As a roofing material for flat or low-sloped roofs, closed-cell SPF conforms and adheres to the surface on which it is sprayed. When applied to the roofing substrate, SPF is seamless and serves as its own flashing over joints, which can eliminate the ability of water to seep through fasteners and seams. Spray foam can be applied in a sloped manner to allow water to easily drain off. When the National Institute of Standards and Technology (NIST) examined buildings following Hurricane Katrina in Pascagoula, Miss., it found that buildings with SPF roofs performed remarkably well. The SPF kept the roofs intact and prevented moisture from entering the buildings, and it also protected the roofs from hail and debris. Only one of the buildings with an SPF roof had notable damage and, in that case, it was minor, affecting a mere 1% of the roof.
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.
- 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.
- Helps conserve energy, reducing CO2 emissions.
- Contributes LEED credits for sustainable, green construction.
- Can help reduce structural damage caused by high winds.
- Contains no formaldehyde or ozone depleting substances.