The practice of using continuous insulation (CI) is hardly new. The material’s use dates well before the 2009 International Energy Conservation Code (IECC) specified CI in various climate zones and construction types to meet the prescribed R-value requirements.
While adoption of CI has grown steadily over the years, and as building codes have evolved to demand higher energy efficiency in residential buildings, misunderstandings around the material persist.
Here are five common misconceptions about CI.
1. Thermal bridging isn’t worth addressing.
Many contractors focus solely on insulating the wall cavities and overlook the thermal transfer through the studs. This is a missed opportunity to build a higher-performing home.
Thermal bridging significantly undermines a building’s overall insulation performance. Look through a thermal imaging camera and you’ll see the heat escaping through the frame.
In fact, a wall made with 2x4 framing with an additional R-5 continuous insulation is about 20% more thermally efficient than a wall made with 2x6 framing.
“Many contractors don't fully appreciate the heat loss occurring through those studs,” says Liang Gwee, Ph.D., Henry’s innovation and emerging technologies manager. “Continuous insulation addresses this by providing a consistent thermal barrier across the entire wall, reducing the energy lost through structural members.”
2. CI adds an unnecessary step.
This misperception stems from a lack of familiarity with modern CI products.
CI made of expanded polystyrene (EPS) or graphite-enhanced expanded polystyrene (GPS) not only keeps a building envelope warmer but also dryer. That’s because it’s more water-resistant compared to common alternatives. In field tests conducted by Henry, EPS and GPS demonstrated less water absorption, allowing it to maintain its high R-value. That means you’re getting both thermal barrier and moisture shield in one product.
“We're trying to establish continuous insulation around the house while also creating an airtight barrier,” Gwee says. “Products like Henry Blueskin VPTech combine these two elements, reducing the need for multiple installations and making the process simpler and faster.”
By using CI products designed to streamline installation, contractors can save time and labor, all while achieving better insulation performance.
3. CI is not worth the cost.
Some contractors view CI as an expense, not an investment. However, home buyers are looking for homes that operate efficiently for lower monthly utility costs. For home builders, CI represents an easy value-add that could give them a competitive edge.
“Continuous insulation helps reduce utility bills and improves indoor comfort,” Gwee says. “It’s an investment that pays off over time.”
4. CI doesn’t improve indoor air quality.
It’s simple: an airtight home is a healthy home.
CI improves indoor air quality by creating a tighter building envelope, which minimizes the infiltration of outdoor pollutants, allergens, and moisture. By reducing air leakage, CI helps maintain consistent indoor temperatures and reduces the need for mechanical ventilation, which can circulate dust and contaminants.
Additionally, having the CI on the sheathing is similar to wearing a winter coat—it keeps the sheathing temperature warm and above the dew point. This reduces risk of mold and mildew, further enhancing the overall health of the indoor environment.
5. CI complicates code compliance.
Actually, CI makes it easier to meet or even exceed building standards. That’s because it gives builders more wiggle room to achieve Home Energy Rating System (HERS) scores.
With CI, builders can make trade-offs to achieve the same performance objectives. An example includes increasing insulation to compensate for larger windows. It’s a performance path versus a prescriptive path to achieving energy performance.
“As building codes become more stringent, continuous insulation provides a straightforward path to compliance,” Gwee says. “It’s not just about meeting minimum requirements but about future-proofing homes against evolving standards.
“The energy code in most states already require CI so the home building industry has an appetite for solutions that makes it easy for the builder,” he adds.
By understanding the versatility and adaptability of continuous insulation, contractors can more effectively navigate changing regulations and provide homes that meet higher standards of energy efficiency.
Blueskin VPTech combines a water-resistive barrier, insulation, and seam sealing in a single, integrated panel, significantly improving energy efficiency, and reducing installation time and associated labor costs by up to 30%. Click here to learn more.
