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Technical library detail

Revising LTTR

Professional Roofing



LTTR; polyisocyanurate; insulation; r-value; PIMA

Faced rigid board polyisocyanurate insulation is the most popular type of insulation used in low-slope roof systems in the U.S. However, after years of debate, there still is no industry-wide consensus of an appropriate R-value for design purposes.

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