Myths about continuous insulation & building enclosures
Explore our webpage dedicated to debunking myths around the design and construction of continuous insulation and building enclosure systems – separating fact from fiction with evidence-based information, clear explanations, and published research.
Debunking Continuous Insulation and Building Enclosure Myths
MYTH
“Thermal bypasses are good.”
FACT
No, they’re not; thermal bypasses are awful for thermal efficiency. Thermal bypasses – commonly referred to as gaps, cracks, and unintended air movement – fundamentally undermine the thermal integrity of building enclosures, reduce efficiency, and lead to significant energy loss. This increases energy demands for heating and cooling. Research indicates that thermal bypasses can cause up to 93% additional heat loss. SMARTci is the only building enclosure system that is guaranteed to eliminate thermal bypasses.
MYTH
“Using self-drilling screws in FRP provides permanent fastening.”
FACT
No, they don’t – Self-drilling screws only provide temporary fastening into FRP and lead to unavoidable failure. Since the structure of FRP degrades continually over time, any fastener attached solely to FRP can only be used structurally in a temporary capacity – especially under extreme temperatures and service loads. On the other hand, CMH performs as well as or better than steel, meaning fasteners attached to composite metal hybrid materials are fastened permanently.
MYTH
“Like steel, FRP has equal strength in both crosswise and lengthwise directions.”
FACT
This is false. Unlike steel, which has consistent strength in all directions, FRP (fiber-reinforced polymer) does not have equal strength crosswise and lengthwise. FRP is anisotropic, meaning its strength depends on the fiber orientation—typically stronger along the fibers and less so in the perpendicular direction. These characteristics require careful consideration when using FRP in structural applications.
MYTH
“If a wall assembly is compliant with NFPA 285, then all components of that wall assembly must be non-flammable, too.”
FACT
This is fundamentally wrong. NFPA 285 assesses the fire performance of full exterior wall assemblies. Other tests, like UL 94 and ASTM E84, assess burning characteristics and flammability/smoke development of building materials, respectively. Each of these industry tests measures different aspects of non-flammability and is not interchangeable. GreenGirt CMH is compliant with NFPA 285 and achieves the highest and safest ratings on both UL 94 and ASTM E84.
MYTH
“If a product has a Declare label, it is automatically Red List free.”
FACT
While a Declare label provides transparency about a product’s ingredients and environmental impact, it does not necessarily mean the product is free of Red List chemicals. The Declare label can indicate the presence of Red List chemicals and categorize them, but it is important to verify the specific details and check for Red List Free certification to ensure the product meets those criteria.
Frequently Asked Questions (FAQs)
Does a higher R-value always mean better insulation?
Not always. High-conductivity materials like steel can create thermal bridging, which can reduce a wall assembly’s overall effectiveness if the sub-framing, fasteners, and cladding aren’t addressed together. R-value can also decline over time from aging, settling, moisture, or temperature exposure, and adding more insulation past a certain point brings diminishing returns. Read more in How to Calculate R-Value for Insulation: Formula & Examples.
Can I use an impact driver to fasten into metal or composite sub-framing?
It’s not recommended. Impact drivers deliver high torque in rapid bursts, which can distort metal, create stress points, and cause internal delamination or micro-cracking in composite materials like FRP. A screw gun (for metal) or a drill driver (for composites) gives more controlled torque and reduces the risk of damage. Read more in When Not to Use an Impact Driver on Metal & Composite Materials.
If a wall assembly is NFPA 285 compliant, does that mean every component is non-flammable?
No. NFPA 285 evaluates the fire performance of the full exterior wall assembly, not the flammability of each individual component.