Spray foam insulation is one of the most advanced and effective ways to improve a home’s comfort and energy performance. But like any building material, it comes with its share of misconceptions—often based on outdated information or poor installations. At Atlas Home Energy, we’ve seen the benefits of spray foam insulation firsthand, and we’ve also seen the myths. If you’ve been doing your research and still aren’t sure what to believe, here’s what you need to know.
Spray foam has been around longer than most people think. First developed by Otto Bayer in the 1930s, it began as an industrial material before making its way into residential construction in the 1970s. Since then, the technology has evolved dramatically. Today’s polyurethane spray foams—both open-cell and closed-cell—are safer, more effective, and more environmentally conscious than their early predecessors.
Reality: High-quality spray foam insulation is low in VOCs and should not have a persistent odor once cured. Any noticeable smell beyond the first few hours is typically the result of improper installation or a low-grade product. When installed by experienced professionals using reputable materials, spray foam should not create any lasting indoor air quality concerns.
Reality: While early formulations lacked fire resistance, today’s spray foams are manufactured with fire retardants and are required to meet strict building code requirements. In fact, most modern spray foams have ignition temperatures well above 700°F—much higher than wood framing or other common building materials. As with any insulation product, proper installation and fire-rated assemblies are key.
Reality: The type of spray foam matters. Closed-cell polyurethane spray foam is highly moisture-resistant and is even used in marine applications, including Coast Guard vessels, due to its ability to prevent water intrusion and resist mold. Open-cell foam can absorb moisture but is vapor permeable and dries quickly without losing its performance. Neither should deteriorate with normal exposure when installed correctly.
Reality: The concern that spray foam stops a home from “breathing” is one of the most misunderstood concepts in building science. All homes—historic or not—need to manage air and moisture movement, but uncontrolled air leakage isn't ventilation. Spray foam, when correctly specified and installed, helps control that movement by reducing infiltration, increasing comfort, and protecting the structure from rot and moisture. In fact, closed-cell foam offers added benefits in historic homes, such as flood resilience, racking strength improvements, and increased wind resistance. What matters most is working with a contractor who understands how to approach complex or older buildings holistically.
Reality: While extreme outdoor temperatures can affect application, professional-grade spray foam equipment includes temperature controls to keep materials at optimal conditions. Since most spray foam in existing homes is installed from the interior, freezing weather is rarely a barrier to proper installation. Cold weather isn’t a reason to delay your project—it just requires a qualified team.
Reality: Spray foam insulation is an investment in long-term performance. Yes, the upfront cost is typically higher than fiberglass or cellulose. But the return comes through lower energy bills, more consistent temperatures, reduced mechanical strain, and even increased property value. It also acts as an air barrier and, in the case of closed-cell foam, a moisture barrier and structural reinforcement—making it more than just insulation.
Reality: Once cured, spray foam is chemically inert and stable. It does not off-gas or release harmful substances into the air. In fact, spray polyurethane foam is used in a range of consumer goods—mattresses, car seats, water heaters, and more. The key is ensuring proper installation and curing time, which is why choosing a trained installer is essential.
Reality: This concern often stems from confusion about heat buildup. Studies, including one by the Florida Energy Center, show that spray foam applied to the underside of a roof increases shingle temperature by only about 2°F—a negligible amount. More importantly, modern building codes (as of 2021) specifically permit air-impermeable insulation like spray foam on the underside of roof decks. Factors such as roof color, slope, and orientation impact shingle life more than insulation type. The small thermal increase does not pose a risk to shingle integrity or manufacturer warranty when the system is designed properly.
Spray foam insulation, like any building solution, isn’t a magic fix. But when it’s specified and installed by professionals who understand how homes actually work as systems, it can offer unmatched comfort, durability, and efficiency. If you’ve heard conflicting information or want to know whether spray foam is the right fit for your home, we’re here to help. At Atlas Home Energy, we take the time to look at your entire home—not just your insulation—so you get results that make sense and last.
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