What is the density of Johns Manvilles building insulation?
Johns Manville produces its thermal fiber glass building insulation (BI) to a specific R-value and thickness rather than a specific density. The density may fluctuate during production in order to achieve the designed R-value at the specified thickness. However, these approximate densities may be used for design purposes. Only the Insul-SHIELD® product line is produced to a specific thickness and density.
