Frequently Asked Questions
Will spray polyurethane insulation absorb or entrap moisture?
- Most moisture problems in houses are due to moisture entry from air leakage. Because spray polyurethane insulation provides such an excellent air barrier, this source of moisture is virtually eliminated. Other potential sources of moisture can be excluded with proper construction techniques and materials. Unusual building use (such as freezers or swimming pool buildings) may require a vapor retardant. Contact Premium Spray Products regarding your specific situation if you have any questions. For more information: read about moisture vapour transmission.
How does closed-cell spray foam provide moisture protection, yet still breathe?
- Unlike cellulose and fiberglass materials, closed-cell foam is impervious to water absorption and wicking. Yet, like Gortex® fabric, the closed cell structure allows the passage of water vapor (high energy particles) to allow your home envelope to “breathe”. Liquid water has much larger particles and is unable to pass into or through a closed-cell foam barrier.
If you spray the underside of a roof deck with SPF insulation, should you vent the attic?
- No, the application of SPF insulation to the underside of the roof deck minimizes the potential for condensation. The SPF insulation develops a thermal and moisture gradient that avoids the development of dew point conditions in the attic. Because of this, moisture won’t condense or accumulate and, therefore, does not need to be vented to the exterior.
Is spray polyurethane insulation code approved?
- Yes. Building codes provide for the use of spray polyurethane insulation. The material and application are described in section 705.1 and 705.2. The code also details the use of thermal barriers.
Can spray polyurethane insulation be applied directly to electrical wiring? What about installed electrical devices like recessed lights?
- Spray polyurethane can be applied directly to electrical wiring. Recessed lights or other fixtures may require a certain amount of air circulation around them for cooling purposes. In these cases, a box can be build around the fixture with gypsum wall board; then spray foam can be sprayed directly to the outside of the box.
At what point in the construction of my house should spray polyurethane insulation be applied?
- Normally spray polyurethane insulation is installed at the same point in the construction cycle as other types of insulation. That is, it should be installed after the rough plumbing, electrical wiring, and heating and air conditioning ducts have been installed. If you decide to seal the entire exterior house shell with spray polyurethane, spray insulation may need to be applied in some areas before the ductwork is installed.
Won’t sealing my house lead to indoor air quality problems?
- Your house does need to proper indoor air quality. 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 outgoing exhaust air. In this manner, you can build an extremely energy efficient exterior shell using spray polyurethane foam while still providing controlled and energy efficient ventilation.
Why is it important to consider the house as a system?
- Each change in construction methods and every new building product affects the whole house. Careful evaluation is critical to avoid negative results, such as adding insulation, which can unintentionally increase moisture accumulation, leading to increased mold growth and structural assembly rot.
Will spray polyurethane insulation strengthen my house?
- Yes! Closed cell foam is rigid and structural. Your walls will be more resistant to winds and you’ll notice less creaking and shaking when doors are slammed or when the kids are romping about.
How does spray polyurethane insulation compare with glass fiber batts and blown-in cellulose?
- Glass fiber batts will not stop air leakage (it might filter out some dirt and dust).
Blown-in cellulose will slow down air leakage.
Spray polyurethane insulation will stop air leakage . . . dead.
Glass fiber batts have an R-value of about 3.5 (1-inch thickness). Blown-in cellulose has an R-value of about 3 to 4 (1-inch thickness). Closed Cell Spray applied polyurethane insulation has an R-value about 6 (1-inch thickness). Glass fiber batts can sag over time; blown-in cellulose can settle over time: both situations leave sections uninsulated and you’ll feel colder because of it. Spray polyurethane insulation completely adheres to wood and sheathing and is rigid; the result is a permanent barrier to heat loss and air entry. Spray polyurethane insulation will add strength and rigidity to your house. Glass fiber batts and blown-in cellulose will not.
What is the difference between low density, open cell SPF and medium density closed cell SPF?
- Low density .5 lb. open cell Spray Polyurethane Foam (SPF) refers to a generic spray polyurethane SPF that weighs between 0.4 to 0.6 lbs. per cubic ft. when fully cured. It is spray applied to a substrate as a liquid and expands about 100-150 times its original volume to form a semi-rigid/flexible, non-structural SPF insulation. The SPF has an R-value around 3.7 per inch and typically uses water as the blowing agent.• Medium Density, Closed Cell Spray Polyurethane Foam (SPF) Medium density, closed cell SPF used in interior applications typically refers to generic spray polyurethane foam that weighs between 1.5 to 2 lbs. per cubic ft. when fully cured It is also spray applied as a liquid to a substrate and expands about 35 to 50 times its original volume to form a rigid, structural SPF insulation with a compressive strength between 15 to 25 PSI. The SPF has an R-value of around 6.7 per inch (aged R-value) and uses high R-value blowing agents.
Doesn’t it cost a lot of money to go green? Is there a return on investment?
- Not only is going green affordable, but the financial and health benefits far outweigh the initial costs. We estimate that it costs from two to four percent more (excluding tax credits) upfront to build a home that uses up to 60% less energy than conventional construction. In fact, the typical payback period is less than five years. You enjoy immediate monthly savings and in most instances can increase the value of your home. In addition, improving the tightness of your home and ventilating properly can result in a healthier environment for you and your family.
What does green or sustainable building mean?
- Building green means requiring fewer non-renewable resources to operate and is healthier to live in. Despite the trendiness of alternative building materials, the greenest thing any of us can do when building or remodeling is to reduce our homes’ reliance on energy (water, gas or electric) and improve its indoor air quality.
How long does it take to install spray polyurethane insulation?
- A typical house can be fully insulated with spray polyurethane in a couple of days. Large houses or houses with complex design features could take longer.
Can a homeowner apply spray polyurethane insulation?
- No. Spray polyurethane application requires complex equipment and a skilled installer. In Canada residential and commercial applications must be done with certified foam and trained installers.
What smells does spray polyurethane insulation produce in my home?
- A slight odor will be present during installation of spray polyurethane insulation. This will rapidly dissipate after the spraying operation stops. After that, the installed spray polyurethane insulation will be odorless.
How does spray foam work?
- A two-part mixture is applied by trained professionals to the inside surface of exterior walls, to the underside of the roof, and beneath floors in basements and crawl spaces. The spray mixture expands rapidly to fill all cracks and voids, completely and permanently adhering to wood, masonry, metal studs and joists.
When can spray foam be installed?
- Spray foam insulation is professionally installed at the same point in the construction cycle as other types of insulation. That is, it should be installed after the rough plumbing, electrical wiring, and heating and air conditioning ducts have been installed, but before the interior walls are completed in new home construction. In some cases spray foam also can be applied in older homes, to the inside of roofs and under floors after construction has been completed.