Frequently Asked Questions – Homeowners

General FAQ

What are the different types of spray polyurethane foam (SPF) insulation and where is it used?

SPF is a tough, resilient solid foam material that can be used to improve energy efficiency in many areas of your home, ranging from air sealing mid-sized holes and gaps to insulating large surfaces in both interior and exterior applications. Several types of SPF are known as two component foam because the chemicals used to make the foam come in two separate containers. The chemicals are combined in a mixing chamber and are applied using a spray pump or spray gun. Generally, two component SPF products fall into two main types, either low-pressure or high-pressure systems:

  • Two component low-pressure SPF kits: used by SPF contractors or weatherization professionals to air seal or insulate small to mid-size areas (e.g., crawl spaces, attics, joist retrofit or to fill seams and gaps in primary insulation).
  • Two component high-pressure SPF systems: used by SPF contractors to insulate larger areas (e.g., new construction – walls and roofs or major renovations).

A professional energy audit on your home can help identify areas where extra insulation or air sealing would be beneficial.

What should I look for in a SPF contractor? What sort of questions should I ask?

As with any professional you would hire for work in your home, a few things you might want to look for in a SPF contractor or weatherization professional include:

  • Appropriate training or certification in SPF installation
  • Insurance
  • A good reputation and references

He/she should be able to advise you on the following:

  • Where to install SPF insulation in your home
  • What to expect throughout each stage of the installation
  • Safety precautions and technical specifications for the products being installed
  • The need to leave your home during installation and an appropriate time after

As an added service, your contractor may also offer guidance on how to take advantage of local and federal utility rebates or tax credits.

Can I install two component spray polyurethane foam insulation myself?

Mid- to larger-scale SPF insulation projects (e.g., walls, attics, roofs) using two component systems are sophisticated applications for professional installation by a trained SPF contractor or weatherization professional. SPF professionals have access to the appropriate training and protective gear (also called “personal protective equipment” or PPE), including respirators, to handle larger-scale SPF insulation jobs.However, there are insulating foam sealant products available in cans for Do-It-Yourselfers at home improvement stores. These products are used for small “bead-type” applications, such as sealing windows, doors, and filling small gaps and cracks.

How long will SPF insulation last? Does the foam degrade over time?

For information regarding the expected lifespan of the SPF insulation being installed in your home, consult your contractor and/or the product manufacturer. One of the benefits of SPF insulation is that it resists structural deterioration/decomposition over time and resists settling.

Can SPF insulation help control moisture in my home?

Gaps and cracks in the building envelope can allow uncontrolled movement of moisture-laden air in and out of the building. Loss of interior moisture control can make the interior air excessively dry or moist, which can cause occupant discomfort, poor indoor air quality, higher heating and cooling costs to control moisture, and in some cases, hidden deterioration of the building and possibly mold and mildew growth. Air sealing these gaps and cracks with SPF can help control interior moisture levels where it is applied. For a list of SPF benefits, go to “Spray Polyurethane Foam Basics.”

Will I have a problem with insects attacking the foam?

SPF helps impede the intrusion of insects and other pests because it can be used to seal the gaps from the outside where insects and rodents typically enter. Although SPF does not tend to attract insects as a desired food source, some pests may chew through the foam over time.


Can I be at home when SPF insulation is installed?

Most manufacturers recommend that homeowners not be present in the home when SPF insulation is being installed and for an appropriate time after to avoid potential exposure to SPF chemicals. Before the job, consult with your contractor for guidance about the period of time before people and animals may reenter your home following installation. If you live in an apartment complex or work in a commercial building where two component SPF insulation is being installed, consult with the building manager and/or SPF contractor regarding measures to help building occupants avoid potential exposure while the foam is being installed.

I have other contractors working in my home. Will application of SPF affect them?

As part of the pre-job consultation with your SPF contractor, discuss the other work being conducted in the home. Connect your SPF contractor with any other contractors working in your home in advance of the SPF application so appropriate arrangements can be made for their protection. Other contractors or workers may need to leave the job site during application and for an appropriate time after.

What should the worksite look like after SPF installation?

You should discuss worksite expectations with your SPF contractor so it is clear what you can expect during every stage of SPF installation. Some general expectations include:

  • Ventilation of the area during and for a short time after installation
  • After the installation, removal of dust, debris and foam trimmings by workers wearing appropriate protective equipment
  • Removal and disposal of any empty and partially used SPF containers or drums in accordance with applicable federal, state, provincial and local requirements


What should I do if I smell an odor after SPF installation?

In the event you have concerns about odors that you believe may be related to the SPF insulation, contact your contractor to ensure proper installation and ventilation procedures were followed and a thorough clean-up was completed. If your concerns are not resolved, your local or state consumer protection office or local or state licensing board for contractors may be able to assist.

Does the SPF insulation in my home pose a fire hazard?

SPF products typically contain flame retardants and are designed to meet building and fire code regulations when installed properly. Consult the product label or manufacturer for more details. It is important to note that cured foam will burn when exposed to direct flame. Therefore, welding or torch cutting or use of a heating appliance that produces a flame near cured foam should be avoided until the foam is protected by an ignition barrier (e.g. drywall).


What are the energy efficiency benefits of SPF insulation?

  • Reduce heating and air conditioning size
    • HVAC sizing can sometimes be reduced as much as 35% without the loss of efficiency and comfort. (Source: Canadian Urethane Foam Contractors Association)
  • Reduce drafts, noise and increase comfort
    • SPF is an effective air barrier when properly applied.
    • SPF is commonly used to prevent drafts from around windows and doors, attics and floor boards creating a more comfortable indoor environment.
    • SPF helps minimize air-borne sound transmission.
  • Impede entry of insects and pests
    • Sealing gaps with SPF from the outside provides a barrier against insects and other pests where it is applied.
  • Minimize air infiltration that can generate condensation and result in mold growth
    • Moisture and humidity inside the home can lead to mold growth. Gaps and cracks in the building structure and condensation on windows can keep the humidity high and support mold and mildew growth. Left unchecked, mold and mildew can cause wood to rot. Air sealing the gaps between the attic and living space can help manage moisture and humidity issues.
  • Seal and insulate areas from small cracks to large areas, such as walls and roofs
    • Because SPF is spray-applied on site, it can more easily insulate and seal the small cracks common in homes. The application also makes larger areas – like walls, attics and roofs – easy to cover in a relatively short amount of time.
    • Depending on the application, different types of SPF may be used. (See “Types of SPF“)
  • Resist settling due to its general stability
    • Typically not subjected to structural deterioration/decomposition and resists settling.
  • Qualify for utility rebates, tax credits and green certification
    • The energy savings obtained by air sealing homes is significant enough that the purchase and use of SPF products may qualify for tax credits under the new American Recovery and Reinvestment Act of 2009. Check with the manufacturer for confirmation that the specific SPF product qualifies for the tax credit and for further information and instructions on filing for the credit.
    • Many local utility companies offer rebates for energy efficiency upgrades. Check with your utility provider for eligibility.
    • To learn more about federal tax credits for energy efficiency, you can visit the ENERGY STAR web site on Federal Tax Credits for Consumer Energy Efficiency.

For new construction or major remodel projects, the use of SPF may help earn energy-efficiency credits under residential green certification programs. A few sources you can visit include: Green Globes, U.S. Green Building Council – LEED (Leadership in Energy and Environmental Design), and National Association of Home Builders – information on scoring details.


Is spray polyurethane foam (SPF) “green” or “bio-based”?

Many products have specific “green” attributes. All SPF has one very important such attribute—energy savings. SPF insulation can reduce the energy needed to heat or cool buildings significantly. And use of SPF insulation reduces electricity demand, conserving valuable fossil fuels and reducing the associated greenhouse gas emissions emitted during electricity production.Some SPF products are formulated with renewable resources such as natural oil polyols based on soybean or castor oil. These natural polyols are chemicals that are mixed and reacted with other chemicals to create polyurethane foam. The finished and reacted polyurethane foam will typically have only a portion of its content as “bio-based.” The foam must meet relevant government requirements in order to make a “bio-based” advertising claim.

How to interpret “green” SPF insulation marketing claims?

When comparing insulation products, one of the first things you will look for is the R-value of the product. The R-value means resistance to heat flow. The higher the R-value, the greater the insulating power.The Federal Trade Commission (FTC) provides helpful guidance on understanding R-value in its Consumer Alert – Home Insulation Basics: Higher R-Values = Higher Insulating Values. Federal regulations require an insulation installer to give you a contract or receipt for the insulation installed that shows the coverage area, thickness, and R-value of the insulation. Once you understand the R-value of the product, you can compare its insulating power to other insulation products.

The FTC issued its Guides for the Use of Environmental Marketing Claims, commonly known as the “Green Guides” to help marketers avoid making inappropriate environmental claims.