Spray Foam Insulation and Blown Cellulose Blanket Contractor


(724) 352-FOAM (3626)

​Steel City Insulation, LLC

What is the R-value of open-cell (semi-rigid) spray foam insulation?

The R-Value is rated at 3.8 per inch. In a 2×4 wall ( 3.5 inches) , the R-Value is about R-13; in a 6-inch wall, about R-21. Unlike foams filled with CFC or HCFC, the R-Value of open-cell spray foam insulation does not decline as it ages. R-Values of insulating materials are measured in laboratories and are designated a nominal R-Value per inch. In the wall or ceiling of a building most factory-made insulation materials suffer a reduction in performance due to air leakage and infiltration. The insulating value of many building components may be as low as 50% of the nominal R-Value of the insulation they contain. By contrast, the insulation of a wall containing spray foam insulation will perform closely to that of the laboratory tested R-Value of the material, and it seals the wall cavity from air infiltration as well. The spray foam insulations are particularly suited for steel or wood frame construction. Open-cell spray foam insulation expands 120:1 as it is installed, adhering to surrounding building components. It completely seals joints, crevices and voids, including difficult-to-insulate spaces such as steel stud “U” and “C” sections, double studs, and non-standard stud locations.

What are the acoustical properties?

Open-cell spray foam insulation has excellent sound absorption properties and sound transmission properties. When comparing spray foam insulations installed by Steel City Insulation to other insulations, there is a very noteworthy difference. As an effective air seal, they eliminate the air gaps through which sound travels easiest. In addition to controlling all frequencies, they are superior in controlling mid-range frequencies that include the most common sounds – the human voice and stereo music.

Does Foam contain urea, formaldehyde, CFCs or HCFCs?

No, spray foam insulation installed by Steel City Insulation  do not contain urea, formaldehyde, CFCs or HCFCs.

Are there health concerns associated with the use of spray foam insulations?

Spray foam insulations installed by Steel City Insulation are “green” products. They meet off gassing requirements of CGSB 51.23 92 for new residential construction, and no toxic or carcinogenic products were detected. In addition, the use of open-cell foam insulation reduces airborne dust and air infiltration, making it the healthy choice for those who suffer from allergies, asthma or chemical sensitivity.

At what stage of construction is spray foam insulation installed?

In new construction, open-cell spray foam insulation is installed after the windows, doors and roof are in, the electrical and plumbing inspections are completed, and after any other electrical or mechanical system located behind the drywall is installed. It is the last installation to take place before drywall is installed.

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 0.5 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.

Open-Cell (semi-rigid) spray-applied polyurethane foam insulation systems (0.5 lbs/ft³) are made up of million of microscopic cells that simultaneously insulate and air-seal. They make residential and commercial structures more energy efficient, comfortable, quieter and less dusty. Open-Cell spray foam insulation is applied as a liquid, which expands into a semi-rigid mass within 10 seconds and automatically seals off drafty areas such as baseboards, headers, sill plates, around windows, doors, electrical outlets, pipes, etc. It also minimizes uncontrolled air leakage throughout the building envelope (wall, ceilings, etc.), thereby reducing energy losses and the possibility of mold, mildew and premature decay.

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.

Frequently Asked Questions About Spray Foam Insulation

Can spray foam insulation be applied in an existing structure?

Spray Foam Insulation can be applied in existing walls when the existing insulation is removed and the wall cavity exposed. In some cases, Steel City Insulation can inject Open-Cell foam into exsisting walls if holes are drilled every 2 Ft. from the inside of the structure, or the outside ( if you are replacing siding.) Excellent results for retrofit jobs are achieved in using open-cell spray foam insulation in the attic and in the crawl space (if applicable). The reason is that a large portion of a building’s energy loss is caused by the “stack effect” – hot air rising therefore creating air movement within a building. Insulating the attic and crawlspace with spray foam insulation eliminates the stack effect.

Who is allowed in the general area during the application of spray foam insulation?

Spray foam insulations shall be installed on site by certified installers who have been trained in the proper safety and handling of the chemicals.Other persons should keep away from the immediate area where spraying is conducted.

Is it possible for owners to install spray foam themselves?

The installer must be a factory-trained and certified contractor using specialized proportioning equipment. The installer has been trained to work with the chemicals involved and has also been trained in a building science to provide the best installation possible.

Are there any issues about overheating of electric wiring?

There is no special requirement needed to encapsulate electrical wires other than what is required with all types of insulation. As with other types of insulation, when the properly rated size and type of electrical wires are used, there is no overheating of those electrical wires.

Does foam support the growth of mold and mildew?

Open-Cell and Closed-Cell spray foam insulation offer no organic food value. Therefore it cannot support bacteria or fungal growth. The effective air-sealing characteristic prevents the movement of hot air to the cold parts of the walls, preventing condensation from taking place within the wall cavities. The elimination of condensation within the wall assemblies prevents the growth of molds and mildew.

What about pests (e.g. roaches, ants, mice and termites)?

Open-Cell and Closed-Cell spray foam acts as a physical and odor barrier that has shown to significantly reduce the number of pests entering structures. It offers no food value, and while it by itself does not present a concrete entry barrier, pests normally do not attempt to go through an area where they cannot detect a food source.


How much does spray foam insulation cost?

Spray foam insulation cannot be compared to conventional insulation. Spray foam insulation actually air-seals the building and eliminates energy robbing air leakage and the associated problems with moisture, mold and mildew and condensation problems inside the walls. When calculating the actual cost you need to consider the possible need to downsize the HVAC systems, eliminate building wraps, and eliminate a significant portion of the material and labor costs associated with an air-sealing approach. The investment to upgrade from standard fiberglass is an insignificant part of the overall cost of a home and your long-term energy costs. When you are planning to install an upgraded insulation package, remember that spray foam insulation is initially more expensive, but provides you with the best performance and comfort value in addition to long-term savings. The additional upfront costs typically pay for themselves in energy savings within three years and will keep on saving you money every year thereafter. It is erroneous to directly compare the cost of fiberglass or loose fill insulation to that of spray foam insulation.

EXAMPLE:   A $1,000 increase in the mortgage for a $200,000 house (~2,200SFH) financed for 30yrs. @ 6% equates to a $6 increase in a monthly payment. It is also reasonable to assume that less HVAC would be required to cool the house – a 2,200SFH traditional fiberglass house in Pennsylvania is usually sized with a single 5 ton unit where a foam house may use a 3 ton unit. At an average price of $1,250 per ton, HVAC equipment savings would be $2,500. A house of this typical size may cost $5,000 more to have foam insulation installed v/s fiberglass – this may result in a total mortgage increase of $2,500 ($5,000 less HVAC saving s of $2,500) or $15/mo. If average monthly utility bills for this home were $300 and foam insulation saved 40% then the new utility bill would average $180.The combined mortgage & utility bill would be $105/mo. LESS than a $200,000 mortgage with fiberglass insulation – return on investment would be two years.  In time, spray foam insulation actuall pays for itself, and will continue to provide "ENERGY SAVINGS FOR THE LIFE OF YOUR HOME".



What are the advantages of spray foam insulation?

Open-Cell (semi-rigid) spray foam insulation remains flexible throughout the life of the building. As the building expands and contracts with changes of season and temperature, it will move with the changes without destroying the seal. As well as simplifying the construction process for the builder, open-cell spray foam insulation eliminates the major causes of building envelope problems – airborne moisture movement and entrapment. Heating and cooling costs are typically reduced by 30 to 50%, and more money can be saved by purchasing a (properly sized) smaller, less expensive HVAC unit. Soundproofing is another benefit that is quickly appreciated in areas such as plumbing runs, media rooms and offices.

Does foam adhere to metal studs and is it compatible with other building materials?

Spray foam insulation adheres well to steel studs and other natural materials such as cement board, wood, etc. Since spray foam will adhere to almost all surfaces, areas that do not require spray foam (such as windows, doors etc.) must be protected from overspray. It is stable in the presence of most solvents found in binders, bituminous materials, wood preservatives, and sealers. It is resistant to facers containing plasticizers, fuel, mineral oil, weak acid, and weak bases, which are typically found in residential and commercial construction materials. Spray foam insulation is non-corrosive and neutral (neither acidic nor alkaline) and will not cause corrosion to metal studs and other metals typically found in construction.

Will sealing my house lead to indoor air quality problems?

Your house does need to be ventilated. Most house design professionals will advise you to seal the house structure as tight as possible and provide the necessary ventilation through the heating and air conditioning system. Many systems employ an "air exchanger" which is designed to pre-condition (either warm or cool) the incoming outside air with the outgoingexhaust air. In this manner, you can build an extremely energy efficient exterior shell usingspray polyurethane foam while still providing controlled and energy efficient ventilation.  "Build it tight and ventilate it right".

Does foam break down, shrink or sag?

The reaction that created the open-cell spray foam insulation is irreversible, preventing the breakdown into its constituent parts. Therefore, Open-Cell spray foam is stable and will not shrink or sag.