Is exact duplication of the physical properties of thermal break materials important?
No, it is not. That is why allowance is made for equivalents and substitutions. What IS important is how well the material performs and satisfies the need at point of use.
“Or approved equal” can be a confusing term in open product specifications if it is not clearly defined in the bid documents. That is because products manufactured or supplied by different companies are very likely to never be exactly alike.
The term “or approved equivalent” typically is what is meant by “or approved equal.” The term “equivalent” acknowledges that different products can serve the same purpose while having similar properties, and they can produce the same results. Functionally, the products are equivalent.
What is critical then when comparing structural thermal break materials?
In the end, it is the structural integrity in the connection design that matters. It is the potential for deflection and creep of a thermal break material in a structural connection that is most critical. Can the thermal break material resist the applied compression force without deflecting? Without creep over time?
What about comparing the physical properties?
Structural thermal break materials have different physical properties. Some values are higher and some lower in comparison to one another. It all comes down to calculations based on these physical properties. It is the connection calculations that reveal whether an equivalent material meets the specification or not – not a comparison of the material properties themselves.
Equivalent Structural Thermal Break Materials – Properties ( 1” thickness)
| Fabreeka-TIM® | Thermal Break Material™ TBM-1 | Armatherm™ FRR | |
| Composition | Fiberglas reinforced laminate | Thermoset Fiberglas reinforced composite | Thermoset reinforced resin |
| Thermal conductivity ASTM C518 | 1.80 BTU/in/hr/ft2/°F | 1.71 BTU/in/hr/ft2/°F | 1.05 BTU/in/hr/ft2/°F |
| Thermal resistance ASTM C518 | R value 0.56/inch | R value 0.58/inch | R value 0.95/inch |
| Compressive strength ASTM D695 | 38,900 psi | 30,000 psi | 40,000 psi |
| Compressive modulus ASTM D695 | 519,531 psi | 400,670 psi | 673,400 psi |
| Shear strength ASTM D732 | 15,000 psi | 14,000 psi | 16,000 psi |
| Flexural Strength ASTM D790 | 25,000 psi | 23,000 psi | Not Given |
Sources:
Fabreeka-TIM®, CSI construction specification, section 05 12 23.9 dated 9-2019.
Armatherm™FRR, CSI construction specification, section 07 21 60.
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of Bell Rubber, Fabreeka International, Inc. and Armatherm owned by the respective entities.
Data is current as of February 3, 2020.