Division 7 Ebook Page 434 FOAMULAR Tapered Roof Insulation, 07 22 16

FOAMULAR DURAPINK , Recover Roof Insulation B. [Insulation Fasteners and Stress Plates]: Furnished by membrane manufacturer. FM approved. Fastener head shall be designed to inhibit damage to the membrane. Minimum 3" diameter or square insulation stress plates shall provide for countersunk fastener heads. Note to Specifier: Consult local building code enforcement authorities. Generally recover roofing over an existing roof will not require the installation of a new thermal barrier because the existing roof serves as adequate separation from an existing steel roof deck. This is a consideration for steel decks only; thermal barriers are not needed for other deck types. C. [Thermal Barrier Material]: Provide one of the following: 1. Gypsum Board: 1/2" (minimum thickness) 2. Rigid Perlite Board: 1/2" (minimum thickness). Note to Specifier: Any separator sheet shall have been evaluated and approved by the membrane manufacturer for adequacy as a separator. In all cases the membrane manufacturer's recommendation regarding insulation overlayment shall prevail. Overlayment protection for chemical separation is not required when DURAPINK insulation is used in conjunction with black or white EPDM, TPO, or most thermoplastic single ply membranes. DURAPINK insulation used in Class A, B or C (ASTM E 108) fire rated recover roofing, or, used under PVC or other thermoplastic membranes which contain plasticizing agents DO require separation from polystyrene. If a loose separator sheet is required, and appropriately fire tested, or approved by the membrane manufacturer, use sheets such as fire rated glass fiber mat. Requirements for overlayment materials and weights may vary. Contact the membrane manufacturer and consult www.ul.com "Certifications" and FM Approvals "RoofNav" for their individual requirements. D. [Separator Sheet:] Provide as required by membrane manufacturer a flexible glass fiber, nonwoven, non- flammable, corrosion and mildew resistant or other suitable separator (overlayment) sheet. E. Membrane Fastening or Adhesion System: Per membrane manufacturer's specifications. PART 3 - EXECUTION EXISTING ROOF SURFACE EVALUATION AND PREPARATION A. Fire rating of the recover roofing system must comply with local building code requirements. All existing roof coverings over which roof board insulation is to be placed must be evaluated for compliance with applicable building code requirements for roof fire classification. roof board insulation products may be placed directly on top of the existing roof covering. Loose gravel ballast may be removed to provide a clean substrate for insulation application; however, the final fire rating may be affected. Check roofing system fire rating listings to determine if fire rating will be affected if gravel is removed. B. The existing roof surface shall be prepared to provide adequate support for the roof board insulation. roof board insulation products are capable of conforming to modest irregularities in the existing surface without breaking. The roof deck should be examined for old equipment curbs, lumps of gravel or asphalt or other irregularities or debris which could affect the integrity or levelness of the new insulation layer. Conditions considered unacceptable by the membrane manufacturer or specifier should be corrected. C. Evaluate existing roof covering over which roof board insulation is to be applied for moisture content. Existing roof surface shall be free of ponded water, ice or snow. This precaution is to discourage potential future condensation on the underside of the recover roofing membrane. Although roof board insulation products are hydrophobic and are unharmed by the presence of moisture, long term entrapped moisture within the existing roof system can promote corrosion of the roof deck and mechanical fasteners. ROOF BOARD INSULATION 07 22 16 - 4

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