Division 7 Ebook Page 528 FOAMULARŪ XPS Insulation ASHRAE 90.1 Prescriptive Roof Insulation Requirements

Technical Bulletin FOAMULAR Extruded Polystyrene (XPS) Insulation ASHRAE 90.1 Prescriptive Roof Insulation Requirements Commercial Low Slope Roof Systems Energy Codes and Standards Above deck roof insulation is prescribed by ASHRAE 90.1 1 , Energy Standard for Buildings Except Low-Rise Residential Buildings. It establishes minimum energy efficiency requirements for most commercial buildings, including larger residential buildings. Excluded are single-family, multi- family three stories or less, and manufactured homes. The International Energy Conservation Code 2 (IECC) is a similar standard that is also widely adopted. The International Green Construction Code 3 (IgCC) contains building energy performance criteria like the other two standards, but also covers sustainable design concepts. For building envelope design, the IgCC generally prescribes higher energy performance requirements than the other two. ASHRAE 189.1 4 , a design standard for high performance green buildings, is designated in Section 301.1.1 of the IgCC as an alternate to the IgCC. Adoption and Compliance Many building code jurisdictions in the United States have adopted an edition of either ASHRAE 90.1, or the similar IECC. The U.S. Department of Energy maintains an energy code adoption website to provide current energy code status by state. http://www.energycodes.gov/adoption/states Compliance paths in general include either a combination of prescriptive/mandatory thermal performance specifications, a combination of mandatory/ Figure 2 Roof Deck Assembly with Insulation Entirely Above Deck Figure 1 USA Climate Zones (ASHRAE 90.1) MECHANICALLY ATTACHED OR FULLY ADHERED SINGLE-PLY MEMBRANE (any type or color) WATER-RESISTANT COVERBOARD (may substitute fire-rated slipsheet only if using a mechanically attached white TPO or PVC membrane) VAPOR RETARDER (optional) NONCOMBUSTIBLE OR COMBUSTIBLE DECK Prescriptive R (minimum) Requirements for Roofs with Insulation Entirely Above Deck Zone ASHRAE 90.1 - 2004 ASHRAE 90.1 - 2007 and 2010 ASHRAE 90.1 - 2013 IECC - 2012 ASHRAE 189.1 - 2011 (alternate to lgCC - 2012)* Non-Res Res Non-Res Res Non-Res Res Non-Res Res Non-Res Res 1 15 20 25 20 20 20 25 2 15 20 25 20 20 25 3 15 20 25 20 20 25 4 15 20 30 25 25 25 5 15 20 30 25 25 25 6 15 20 30 30 30 30 7 15 20 35 35 35 35 8 20 35 35 35 35 Non-Res (Non-Residential) Res (Residential) * Section 605.1.1 of the IgCC-2012, regarding "Building Envelope Systems, Prescriptive Compliance", states that when the IgCC is used, the building thermal envelope R shall exceed the requirements of the IECC by not less than 10%. Other variations of this assembly may include metal roofing, other mechanically attached or fully adhered membranes, other colors such as black, and other cover layers such as a lightweight fabric slip sheet as appropriate for each system. THERMAPINK insulation is applied direct-to-deck in accordance with Underwriters Laboratories Roof Deck Construction #457, tested in accordance with ANSI/UL Standard 1256.

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