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New LTTR values

Professional Roofing



PIMA; polyisocyanurate; insulation; R-value; LTTR

In June, the Polyisocyanurate Insulation Manufacturers Association (PIMA) announced its QualityMark-certified R-value program is being updated to incorporate a new test method for determining long-term thermal resistance (LTTR). As a result, new LTTR values are going to decrease from current values. If you are involved in the design, procurement or installation of roof systems that include polyisocyanurate insulation, you should be aware of these upcoming changes.

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