Have questions about foam insulation? Here are the questions we are most often asked. If you don’t see a particular question that you are interested in, please use our contact form to ask your question and we’ll get back to you with an answer. We try to answer all questions within a day or so.
- What is spray foam insulation?
- Is spray foam insulation a new technology?
- If spray foam insulation is so much better than fiberglass and cellulose, why isn’t everyone using it?
- Is spray foam insulation code-approved?
- Is it true that no contractor’s license is required to install insulation?
- I am confused about the difference between open-cell and closed-cell spray foam insulation. How do I choose between the two?
- Will I save money if I insulate with spray foam insulation?
- I’ve seen ads for spray foam insulation kits on the Internet. Is there any reason why I can’t apply spray foam insulation myself?
- Is spray foam insulation a safe product for my home?
- How long does spray foam insulation last?
- Does spray foam insulation absorb or trap moisture?
- I have heard that a roof leak could rot my roof if I have spray foam insulation on the underside of the roof deck. Is this true?
- Will spray foam insulation on the underside of my roof sheathing void my roof warranty?
- Can spray foam insulation be applied directly to electrical wiring? What about installed electrical devices like recessed lights?
- What if we want to add or move an electrical outlet after spray foam insulation is installed?
- I’ve seen pictures that show big uneven bumps of spray foam insulation bulging out of an unfinished frame wall during renovation or new home construction. Does this create a problem when installing the drywall sheathing?
What is spray foam insulation?
Spray foam insulation is created by using special equipment to mix two chemical ingredients together. The resulting mixture is applied with a spray gun to a building structure, such as the interior surface of drywall or the underside of plywood roof sheathing. The liquid spray mixture expands from 30 to 100 times its original volume—depending upon the specific foam product—and hardens into a solid plastic barrier within less than 10 seconds. Spray foam bonds chemically to the surface it is applied to. With closed-cell spray foam, this bonding action adds strength to a wall or roof structure.
Spray foam’s behavior of expanding when applied allows the foam to fill even the smallest cracks and openings, sealing walls and roof structures against air infiltration. This ability to block almost all air infiltration gives spray foam insulation a big part of its dramatic insulating performance advantage over fiberglass and other fiber insulations.
Is spray foam insulation a new technology?
No. Spray foam insulation appeared during the 1960s. The first applications were for commercial cold storage facilities and industrial projects. Insulation contractors later applied spray foam to roofing systems. An interesting historical note: Energy costs were not really a concern during the 1960s. Spray foam insulation was actually first tested in roof structures because of its water resistance.
If spray foam insulation is so much better than fiberglass and cellulose, why isn’t everyone using it?
This is a fair question. There are three reasons. First, the earliest spray foam insulation products contained large amounts of formaldehyde. As safety concerns about toxic building materials emerged during the 1970s, spray foam insulation fell out of favor. Today’s spray foam insulation products do not contain formaldehyde.
Second, fiber insulation products are less expensive than spray foam insulation. This gave a decided advantage to fiberglass insulation products during the era of cheap energy. Today, with spiraling energy costs, spray foam insulation is a much better long-term value than fiberglass or cellulose insulation.
Third, we now know from modern building science research that about 40 percent of indoor air conditioning and heating costs are attributable to air infiltration through walls, ceilings and attic spaces. Fiber insulations are completely porous and don’t do a very good job of blocking heat transfer related to air infiltration. Spray foam insulation, on the other hand, virtually eliminates air infiltration through insulated structures.
Is spray foam insulation code-approved?
Yes. Building codes provide for the use of spray foam insulation in the Foam Plastic section. This section of the code also describes requirements for thermal barriers.
Is it true that no contractor’s license is required to install insulation?
Unfortunately, this is true. And it’s too bad because incorrectly installed insulation can rob you of valuable energy savings and, in the case of fiberglass and cellulose, create conditions for mold, mildew and unhealthy air quality. In addition to having independently verified knowledge and experience, state-licensed contractors are required to meet a variety of financial and continuing education requirements. Tailored Foam of Florida is a state-certified general contractor, and we’ve installed more spray foam insulation than all the other insulation companies in Florida and Southern Georgia combined.
I am confused about the difference between open-cell and closed-cell spray foam insulation. How do I choose between the two?
We get this question a lot. The short answer is that open-cell spray foam is less expensive and, while superior to cellulose or fiberglass in insulating power, air infiltration and moisture blocking, and promotion of healthy indoor air quality, open-cell spray foam has less insulating power per inch than closed-cell spray foam and doesn’t add structural strength to walls and roofs.
Closed-cell spray foam insulation has all the benefits of open-cell spray foam, with almost twice as much insulating power per inch. Plus, the density and sticky closed-cell quality of closed-cell spray foam can add significant strength to frame walls and roof structures. Which should you choose? It depends upon a variety of factors including your budget, geographic location, your energy saving goals and other factors.
You can make the most informed decision by scheduling a visit with a Tailored Foam representative. While, as a practical matter, most of our work in existing homes is limited to new attic insulation, the agenda for a site visit can include the following tasks:
- survey your home’s construction, existing insulation and the accessibility of your attic and walls;
- measure roof and exterior wall surface areas;
- explain different spray foam insulation types and product options;
- explain utility and government financial incentives
- explain state-mandated windstorm loss mitigation discounts on your homeowners insurance; and
- provide you with a firm quote for installation of spray foam insulation in your home.
Will I save money if I insulate with spray foam insulation?
Yes! The installed cost of spray foam insulation is higher than the cost of fiberglass or other fiber insulation products. On the other hand, this higher initial cost is offset to some degree because no wrap material is necessary and—especially in new construction—you may be able to reduce the size of your central air conditioning equipment.
Air conditioning and heating costs are substantially less, even when spray foam insulation replaces fiberglass or cellulose insulation in an existing home. Research shows that homes insulated with spray foam insulation use 20 to 40 percent less energy than homes insulated with traditional fiberglass or cellulose. Your savings may vary, depending upon your home’s location, appliances, the surface area and orientation of windows, and other factors.
I’ve seen ads for spray foam insulation kits on the Internet. Is there any reason why I can’t apply spray foam insulation myself?
We do not recommend it. Applying spray foam insulation requires complex equipment, including a plural component proportioner pump with heaters, dual high pressure heated hoses, a high pressure mixing spray gun, feed hoses, an air compressor and safety equipment. While spray foam insulation is completely safe once it hardens, the raw ingredient chemicals can be harmful if inhaled or in contact with the skin. Inexperienced installers also have a tendency to underestimate the foam’s expansion, so they waste ingredients by overspraying.
It takes training and experience to apply spray foam insulation with the consistency and quality control necessary to achieve designed performance. Problems can arise if the foam chemicals are mixed in the wrong ratio or at the wrong temperature, causing the cured foam to crack and shrink away from rafters or studs. And working too fast can leave voids in the finished foam, reducing its insulation value.
Is spray foam insulation a safe product for my home?
Yes. Once applied, spray foam insulation hardens into a solid material and does not release toxic gases. You can find more extensive information on spray foam insulation safety here.
How long does spray foam insulation last?
The oldest spray foam insulation applications are over 40 years old. Cured foam insulation is chemically inert, so its physical properties change very little with age. The most important factor in longevity is quality control during the original application: maintaining precise temperature control and correct chemical mixture ratios when preparing and applying the foam.
Does spray foam insulation absorb or trap moisture?
Closed-cell spray foam insulation does not absorb moisture. Period. Open-cell spray foam insulation absorbs moisture but then dissipates the moisture within a relatively short period of time. This is unlike cellulose or fiberglass, which are porous and will allow moisture to pass right through the insulation, soaking the insulation and ruining its insulating power in the process.
Most moisture problems in houses result from air infiltration through walls and ceilings. Spray foam insulation expands to fill even the smallest cracks and openings in walls and roof sheathings, so these moisture sources are virtually eliminated. Proper construction materials and techniques usually prevent moisture buildup from other sources. Contact us if you have questions about an application with unique moisture characteristics, such as an indoor swimming pool room or a walk-in freezer.
I have heard that a roof leak could rot my roof if I have spray foam insulation on the underside of the roof deck. Is this true?
No, this is not true. Some fiber insulation companies have created illustrations that show water from a roof leak draining down the underside of the roof deck in a spray foam insulated attic. Their suggestion is that water from a leak will become trapped in a space between the roof deck and the spray foam insulation, leading to eventual roof rot.
However, this scenario is not possible because spray foam insulation forms a direct chemical bond with the roof trusses and the underside of the roof sheathing. There is no gap between the roof sheathing and the spray foam insulation, so there is nowhere for water to go. In fact, spray foam insulation on the underside of your roof deck actually protects your ceiling and valuables by preventing water from leaking through your roof sheathing.
Will spray foam insulation on the underside of my roof sheathing void my roof warranty?
No, this is another myth. The suggestion here is that your roof sheathing and shingles will not last as long because the spray foam insulation increases the roof surface temperature, by preventing heat from radiating into the attic. While your roof surface temperature may be a bit higher, research shows that the temperature increase is only two to three degrees. For a Florida roof surface that can reach 160 degrees or more during the summer, this is a difference of less than two percent. By comparison, the roof temperature increase just from installing dark colored roof shingles is three times greater.
Can spray foam insulation be applied directly to electrical wiring? What about installed electrical devices like recessed lights?
Yes. Spray foam insulation can be applied directly to electrical wiring. Properly sized wiring should not experience temperature issues. Recessed lights or other fixtures may require a certain amount of air circulation around them for cooling purposes. For fixtures, consider building a box around the fixture with gypsum wall board (drywall). The spray foam insulation can be applied to the outside of the box.
Incidentally, cellulose insulation is recycled paper and should not be placed in close proximity to recessed lighting fixtures. Even though cellulose insulation is treated with fire retardent chemicals, tests show these chemicals tend to lose their effectiveness over time.
What if we want to add or move an electrical outlet after spray foam insulation is installed?
Your electrical contractor can pull wire through the insulation. If you have a situation where wiring may require periodic access, such as a home theater room, we recommend that you place ENT conduit within the wall structure before the spray foam insulation is applied.
I’ve seen pictures that show big uneven bumps of spray foam insulation bulging out of an unfinished frame wall during renovation or new home construction. Does this create a problem when installing the drywall sheathing?
No. After the foam has set and hardened, the technician uses either a straight edge scraping tool or a hand saw that is wider than the space between the framing studs to remove any spray foam insulation that has expanded out past the width of the frame wall. The finished foam insulation surface is smooth and level with the faces of the exposed framing studs.