Division 7 Ebook Page 532 THERMAPINK® XPS Insulation in Architectural Metal Roof Covering Systems

Technical Bulletin Architectural Metal Roof Covering Systems THERMAPINK Extruded Polystyrene (XPS) Insulation Building Interior Moisture Protection Due to THERMAPINK insulation's low water absorption, designers may consider omitting the layer of saturated felt underlayment sometimes placed under architectural metal roofing, over the insulation, to serve as a protection layer against condensation that may form under the metal and drip to the insulation layer below. When the underlayment is omitted, the XPS joints should be sealed with a tape recommended by its manufacturer for that application. Taping XPS joints, or the use of an underlayment over the insulation, may provide temporary and partial water shed protection to the interior of the building if the installation of the metal roof covering is delayed. 4) Metal Roof Panel Underlayment THERMAPINK insulation may be covered with a full coverage underlayment material recommended by its manufacturer for use under architectural metal roofing systems. Prior to installation of the underlayment material, insure that the surface is clean, dry and, if recommended by the underlayment manufacturer, properly primed with a water based primer. Solvent based primers cannot be used as they will damage THERMAPINK XPS insulation. UNDERLAYMENT NOTES: Owens Corning does not recommend a particular underlayment. Underlayment manufacturers designate certain specialized products for applications where higher in-service temperatures are expected. Before use, verify that the underlayment material is recommended by its manufacturer for use in the system. See Section 2 regarding immediate coverage of black underlayment over THERMAPINK insulation with metal panels. 5) Warranties Single source complete system warranties are available from some metal roof system manufacturers. Owens Corning provides a Lifetime Limited Performance Warranty 1 for THERMAPINK insulation physical properties including retention of 90 percent of its advertised R-value for the life of the building. Full system specification and construction details are the responsibility of the metal roof manufacturer. 6) Building Code Specifications Underdeck Flame Spread (UL 1256) THERMAPINK insulation is permitted to be installed directly over structural steel roof decks, under metal roof panels, without a gypsum board thermal barrier, as detailed in Underwriters Laboratories (UL) Roof Deck Construction #457. Verify acceptance with local building code officials. Fire Resistance Ratings (in hours) (ASTM E119) Time rated fire resistance assemblies require a layer of 5 /8", Type X, gypsum board to be installed over the structural steel deck in accordance with details a UL or other third party listed assembly. All types of foam plastic insulation require a gypsum board layer over the steel deck, or some form of additional protection, when installed as a part of an hourly fire resistance rated roof system. Additional protection may consist of gypsum board installed on top of the deck, or sprayed cementitious coatings on the bottom side of the deck. Exact details, types and amounts, for additional protection are determined by the specifications provided in the third party assembly listing. Class A Rating (top side flame spread and penetration) (ASTM E108) Insulated architectural metal roof covering systems can be Class A fire rated over both non- combustible and combustible decks. Consult the Underwriters Laboratories (UL) On-Line Certifications Directory for additional information. Uplift Resistance Classified, Class 90 (UL 580) THERMAPINK insulation is accepted for use in UL Class 90 wind uplift classified assemblies. See UL Roof Deck Constructions such as 303, 238, 238a or 238b for typical specifications. Many other listings exist for uplift classification of architectural metal roofing. See the metal roof covering manufacturer's specific listings for complete details.

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