Editor's note: The opinions in this article are those of the author's and not NRCA.
Stone wool insulation provides roof system designers with various design alternatives, allowing them to increase a roof system's overall performance. When used with foam plastic insulation, stone wool insulation can help maintain a roof system's thermal performance.
Roof system designers have an increasing number of choices when it comes to insulation, and every designer must rely on a number of criteria. According to The NRCA Roofing Manual: Membrane Roof Systems—2011: "An ideal roof insulation would have the following properties: compatibility with bitumen and other adhesives; component compatibility; impact resistance; fire resistance; moisture resistance; thermal resistance; stable R-value; attachment capability; dimensional stability; and compressive strength. … In reality, no single commercially available rigid board insulation product currently available has all these ideal properties. Therefore, designers need to choose rigid board insulation materials that have properties best suited to specific project conditions."