Spray Foam Explained & Our Solution

Greening the House specializes in this new technology. 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.

Please contact us to discuss your ideas and how we can assist you in future Spray Foam / Insulation goals. Call us toll free 866.781.2028 or you can submit a request for an appointment by clicking here.

Be sure to review the "Government Funding Options" section of our web site. Its located directly above in the navigation menu. This section contains a detailed list of all the stimulus funds available to help fund your next project.

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:

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

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

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 F, 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.

• 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.

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.

Closed Cell vs. Open Cell Foam

What is the Difference between Open-cell and Closed-cell Polyurethane Foams?
This may be one of the most important pages on the website if your interest is in spray foam insulation. When it comes time to actually put the foam product in your home or commercial building structure, you must identify whether you will use .05 lb./cu. ft., open cell foam, or 2.0 lb./cu. ft. closed cell foam. This makes a big difference in cost, application methods, and performance.

With the open-cell vs. closed-cell issue, there are two major factors to understand and consider. The first is the nature of the foam. It is either open-cell foam, where the tiny cells of the foam are not completely closed. They are broken and air fills all of the “open” space inside the material. This makes the foam weaker or softer feeling than closed-cell foam.

Closed-cell foam differs in that all of its tiny foam cells are closed and packed together. They are filled with a gas that helps the foam rise and expand and become a greater insulator. These cells can be formulated to obtain many characteristics, the most common being size and density.

Density is measured by weighing one solid cubic foot of foam material. Open cell foams typically weigh in at 0.4 to 0.5 lb./cu. ft. Closed cell foam for insulation applications range in density from 1.7 lb./cu. ft. to 2.0 lb./cu. ft. Roofing applications typically use a 2.8 to 3.0+ lb./cu. ft. to support traffic and loads better. The higher the density the foam, the heavier, or stronger it becomes. Some polyurethane foams are molded into decorative interior molding and painted or stained for a simulated wood effect. These “higher density” foams are typically in the 30 lb./cu. ft. to 40 lb./cu. ft. density range.

The advantages of closed-cell foam compared to open-cell foam include its strength, higher R-value, and its greater resistance to the leakage of air or water vapor. The disadvantage of the closed-cell foam is that it is denser, requires more material, and therefore, is more expensive. Even though it has a better R-value, typically the cost per R is still higher than open-cell foam. The choice of foam can also be based on the requirements for the other performance or application specific characteristics such as strength, vapor control, available space, etc.  Open-cell SPF has an R-value around 3.5 per inch and typically uses water as the blowing agent.  Closed-cell SPF has an R-value of around 6.0 per inch (aged R-value) and uses high R-value blowing agents.

Both types of foam are commonly used in most building applications and the choice for which to use can depend on many of the factors discussed above. Some foams are inappropriate in specific applications. For example, you typically would not use open-cell foam below grade or in flotation applications where it could absorb water; this would negate its thermal performance because water is a poor insulator compared to air. Closed-cell foam would be a good choice where small framing sizes need the greatest R-value per inch possible. Closed-cell foam would be used for roofing applications.

Always contact your material supplier for performance and application data on their specific materials. What type of foam being used in your building or home is always a good issue to discuss with your spray foam installation professional up front, before the job starts.

Spray Foam Improves the Buildings Envelope

The building envelope is a total system of construction materials and design components that control the temperature, movement of air, and moisture both into and out of the building.  A building's insulation, air barrier and vapor barrier all need to work together to achieve a more stable, comfortable and healthier indoor environment.  Many new materials and design practices are being implemeted to extend the sustainable service life of buildings and homes.

Build it Tight, Ventilate Right.
Ventilating the Attic and the Crawl Spaces has long been the traditional and code required method of home design and building.  However, ventilation of these spaces was required because standard materials and building design practices were not capable of addressing radiant heat transfer, condensation, and the results of “stack-effect issues.”

In order to address heat transfer form weather issues, utilities, and the formation of moisture due to condensation and air infiltration, the only option was to ventilate the attics and crawl spaces.  The major problem with ventilating these spaces is that the air brings moisture, pollution and other adverse problems and challenges with it.  Furthermore, the vents to allow it in create voids in the building for insects and rodents to enter, and all our nice conditioned air that escapes, or is pulled from the living spaces to exit.

In fact, in the summer, the incoming air needs power consuming fans to bring it in, and it will never get any cooler than the outside air temperature.  Why would we want 95 degree hot, humid, potentially pollution ridden air into our attic and crawl space?  In the winter this air is freezing cold. 

If our heating/cooling utilities and ducts are located in the attic and/or crawl spaces (most usually are) then their radiant contact with the ducts will cause them to loose up to 10% or more of the hot or cold air flowing through them due to radiant transfer.  Worse yet,
Moisture and mold can also form within the ducts during certain temperature conditions, causing adverse health affects to the building occupants or your family.

Another major reason that traditional methods call for attic ventilation is that during the hot summer months, heat from the sun builds on the roof and radiates into the attic space.  In fact, it can build to upwards of 130 to 150 degrees or more.  (see our section on Urban Heat Islands).  This extreme heat radiates into the attic and the living space causing condensation and the potential for mold.  Our air conditioning systems also need to work harder and consume more energy with all this heat directly above our heads.  The extreme heat also makes it very uncomfortable to enter these spaces. 

Most builders and design professionals are not familiar with modern materials and progressive building science techniques that can virtually eliminate all of these problems that force the traditional, less effective requirement for ventilation in these building spaces. 
Builders and design professionals will also make the argument that your home needs to breathe.  Well, they are absolutely correct.  But why rely on cracks, gaps and holes in your building for passive ventilation, when you can build your home tight, healthy and energy efficient, and let the mechanical ventilation systems due the job properly.

Spray foam insulation can still provide benefits far greater than traditional materials such as fiberglass and cellulose, regardless of whether you decide to ventilate these spaces or not.  By using spray polyurethane foam insulation you can increase your home's energy performance, structural integrity and air quality.

This section will highlight further advantages of spray polyurethane foam insulation, methods of construction and its specific use in the Building Envelope.