Sealed Deal

By Jason Faircloth from the 2009 Publication of the Remodeler's Resource

"While the initial cost of improved insulation may be higher than traditional fiberglass, it is an investment that returns dividends with every energy bill."

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Sprayed-in-place insulation, including both polyurethane spray foam and wall spray cellulose, has been utilized in the home and commercial building industries for over three decades, and it is know quickly pulling away from the pack.

While traditional batt or rolled fiberglass is still a cost effective way to insulate homes and businesses, it does have a few diminishing characteristics that have led some builders and homeowners to spend more up front for a tighter building envelope. The issue is that in a real world application it is rare for a uniform piece of insulation to fit into a nonuniform wall or ceiling cavity. Even when the studs are appropriately spaced, a large majority of the cavities contain electrical wires, plumbing pipes, or metal tie downs. The only way to apply the standard piece of fiberglass is to precisely cut it to fit or compress it, both of which drastically reduce its insulating capabilities. That’s where a sprayed in place insulation shines.

The two major players in this game are a recycled paper product known as cellulose and a polyurethane mixture that reacts during installation to create a plastic foam. This eliminates the possibility of having voids or cracks in the insulation layer of your building envelope. Both products fill the cavity despite other items being contained within the space behind drywall. Neither products have an adverse affect on other building components such as corrosion and actually aid in the prevention of mold and mildew issues that are a nightmare for any homeowner. For further similarities and differences, let’s look at each product individually.

It does not get much “greener” than using a product made up of as much as 85% post-consumer recycled paper. It has been estimated the average home insulated with cellulose insulation uses 39 trees worth of paper. This paper is rescued just before entering a landfill and is given a whole new life. The manufacturing process uses 10 times less energy than fiberglass while creating zero emissions from the factory. It is safer in the event of a fire due to its high density and the fact that it is treated with a fire retardant that is usually some sort of borate compound, the same compounds used by pest control companies for insect and rodent prevention. It improves the sound control of a structure as well as reducing the airflow through the exterior of the building. This point, above all else, is what gives it the greater insulating capabilities, and while the extremely cost effective cellulose does a great deal to cut down on air infiltration, the foam eliminates it completely.

Foam insulation comes with many names and even more preconceived notions about what it is and is not capable of accomplishing. The two residential applications available include both the half-pound and two pound per cubic foot densities. These are often referred to open cell and closed cell respectively. They are both considered air barriers, meaning they meet certain criteria set forth by regulatory bodies to show that they allow negligible amounts of air to pass through them at a certain thickness. The other notable difference between them and the aforementioned cellulose is in the attic of a home. While traditional building science has told us to allow and even aid in the air movement in and out of our attic spaces with the use of vents and fans in turn insulating the ceiling of a structure to keep the extreme heat buildup that occurs out of our living space, new technology allows us to fight the battle at the roof line and prevent the attic from heating up in the first place. Notably, the density of the cellulose lends it to perform better than fiberglass batts or blown fiberglass, however it is still applied with the old way of thinking on the ceiling. Alternatively, spray foam adheres directly to the underside of roof decking and results in the entire attic space being considered conditioned space. Any mechanical equipment contained therein would then be protected instead of being exposed to an attic situation that is frequently over 150 degrees Fahrenheit, undoubtedly prolonging the life and reducing the maintenance of the equipment. However, the benefits of foam insulation do not stop with thermal protection.

“Closed cell foam actually adds structural rigidity to a home,” explains Kevin Bentley, President and CEO of BCI Insulation. “It weighs two pounds per cubic foot, is highly dense and is capable of greatly increasing the wind load of home’s roof.” Some manufacturers have even shown roof structures withstanding Category 5 hurricane testing. In these tests, shingles were removed from the roof deck, but the decking itself was not compromised leaving the interior of the home unharmed. One could only imagine the level of return on investment that would be experienced in the event of a hurricane, but the cost savings don’t rely solely on saving your home from a natural disaster.

Insulators are well aware that in this market, price is everything. It is one thing to explain saving on your energy bill or prolonging the life of HVAC equipment, but most buyers want to know the dollars and cents of what they are getting into. Cellulose manufacturers advertise savings to be 30 to 40% of your energy bill, while foam companies increase that to 40 and even 60%. That sounds great to most people, but what about the cost associated with the upgrade? Among most installers you can expect 10 to 15% more investment on the cellulose, which on average translates to a few hundred dollars. Some manufacturers now offer to calculate a correct sizing of your HVAC unit, and if they are able to reduce it even by half a ton (the accepted unit of measure for this type of equipment), you will spend less on the total cost and have a more efficient home. Spray foam will cost even more initially, however it is difficult to give a percentage increase due to the fact that you are insulating a different area. The ratio of roof square footage to ceiling square footage varies depending on the slope of the roof, and it is also necessary to insulate any gable ends within the attic space as well as blocking off and spraying areas where the roof extends over porches or garages. It is best to have a professional measure each individual project.

The bottom line is with the energy crisis in full swing, it is only a matter of time before these options are made standard. When that happens there will be a drastic difference in homes built using traditional insulation and these more energy efficient products. It will be a common question asked when purchasing a home or assessing a builder’s commitment to quality. It is an easy process to retrofit an existing home with either of these products and bring it back into contention when it is ready to go back on the market. Which brings us to the last and potentially greatest return: resale value.