Lose the attic vents using spray foam

For today’s builders and homeowners, energy efficiency, resiliency, and long-term home comfort are top priorities. Insulation plays a critical role in meeting these demands by preventing energy loss, managing moisture, and enhancing structural integrity. Among the most effective solutions available to Canadian contractors is spray foam insulation, a more modern and higher-performing alternative to traditional materials like fiberglass and cellulose. A well-insulated home with spray foam can also contribute to a property’s curb appeal and value.

Understanding the Role of Unvented Attics in a High-Performing Building Envelope

A properly constructed building envelope is the critical barrier between indoor and outdoor environments, playing a key role in a home’s energy efficiency and durability. An increasingly popular innovation in modern home construction is “unvented” attic design, which regions in North America have begun incentivizing. For example, recent legislation in Florida provides new standards and insurance premium reductions for the construction of unvented attics as a strategy to enhance home performance and resiliency against extreme weather. Similar programs may reach Canada in the future, but until then, Canadian contractors can still incorporate unvented attic construction into their projects. These designs help reduce heat loss, enhance moisture control, and reinforce a home’s structural stability against severe weather conditions – leading to a high-performing building envelope.

Why Spray Foam Insulation?

Spray foam is the preferred insulation for an unvented attic, as it effectively seals the attic space, preventing energy loss and humidity fluctuations. By maintaining a consistent indoor climate, spray foam helps reduce strain on HVAC systems, ultimately leading to greater energy efficiency and long-term cost savings. Contractors can educate homeowners on the long-term value of spray foam insulation, helping them make informed decisions about their home’s energy efficiency and resiliency in the face of increasingly frequent and severe weather events.

Spray foam insulation comes in two categories, each offering unique benefits for different applications. Open-cell spray foam is a flexible and cost-effective insulation that expands to fill gaps, creating an effective air barrier while also providing sound-dampening benefits. Closed-cell spray foam offers a higher R-value per inch, enhances structural reinforcement, and provides superior moisture resistance. In addition to air and thermal control layers, closed cell foam adds condensation control making it a perfect solution for building envelopes in cold climates like Canada. By choosing the right type of spray foam for a project, contractors can optimize energy efficiency while improving the durability and overall performance of a home. Closed-cell is preferred for unvented attic construction due to moisture resistance qualities.

The Connection Between Insulation and HVAC Efficiency

Beyond improving energy efficiency and durability, spray foam insulation contributes to a well-sealed and high-performing building envelope. This airtight seal helps prevent air leakage, one of the leading causes of energy loss, while also enhancing moisture control and structural reinforcement. These advantages make spray foam insulation a valuable investment for both homeowners and builders. Its closed-cell formulation can help enhance a home’s structural strength, with the potential to increase transverse and lateral shear strength by up to 300%*. Additionally, spray foam can help reduce the risk of mold, mildew, and condensation buildup while enhancing a home’s structural resilience against extreme weather conditions. Unlike other insulation materials, spray foam maintains a stable R-value over time, resisting sagging or settling that can compromise insulation effectiveness.

Moving Toward More Efficient Homes

Proper insulation not only improves a home’s thermal performance but also plays a vital role in optimizing HVAC efficiency. There are several manufacturers that have developed next-generation heat pumps that perform reliably in all North American climates down to -22°F. One such example by Midea was featured in a recent Discovery Channel mini-documentary about the renovation of Willow Ranch, an Alaskan home for adults with intellectual and developmental disabilities. When paired with a high-performance heat pump system like this, spray foam insulation enhances energy savings and overall home comfort. Specifically, spray foam can potentially lower the overall thermal load of the home, decreasing the BTU’s needed to heat and cool. After spray foam, contractors can specify right-sized (smaller) HVAC systems, helping homeowners save on the initial purchase price and preventing inefficiencies that can occur with oversized equipment. This ultimately results in lower energy costs for homeowners, reduced strain on heating and cooling systems, and improved indoor air quality and humidity control. Contractors interested in learning more about integrating advanced HVAC solutions can experience these technologies firsthand at a heat pump showroom, which manufacturers like Midea are beginning to open across North America.

As the demand for energy-efficient, long-lasting homes continues to rise, Canadian contractors must stay ahead by adopting innovative building materials and construction techniques. Spray foam insulation, especially when used in unvented attic designs, delivers measurable benefits in efficiency, resilience, and longevity of a home. By incorporating modern insulation methods, builders can optimize energy efficiency, reduce environmental impact, and enhance customer satisfaction. With the introduction of Enverge 1860 CDN Closed Cell Spray Foam in Canada, contractors now have access to insulation technology specifically engineered for the Canadian market, helping them build stronger, more sustainable homes for the future.

About the author

Aaron Davenport is one of the nation’s leading building science consultants with over 20 years of experience in the field as a builder and consultant. His understanding of building science drives his passion for expanding the building market so that homes and buildings are smarter and more efficient resulting in people living better. He is proud to serve in his current role at Holcim Building Envelope as the Director of Building Science, Enverge Spray Foam.

*As determined by NAHB Research Center. 1992. Results may vary.