A. Insulation Installation, General: 1. Install roof insulation in accordance with roofing system manufacturer's written instructions. 2. Install roof insulation in accordance with requirements of FM Approval's Listing for specified roofing system. B. Insulation Thickness: 1. Thickness of roof insulation shown on drawings is nominal. Actual thickness shall provide the average thermal resistance "R" value of not less than that specified in Performance Requirements Article. 2. When thickness of insulation to be used is more or less than that shown on the drawings, adjust the alignment at roof drains, flashing, fascia's and similar items at no additional cost to the Owner. 3. Where tapered insulation is used, the thickness of the insulation at high points and roof edges shall be as shown on the drawings. The thickness at the low point (drains) shall be not less than 1.1/2-inches. 4. Use not less than two layers of insulation when insulation is 2.3/4-inches or more in thickness unless specified otherwise. Stagger joints minimum 6-inches. C. Lay insulating units with close joints, in regular courses and with cross joints broken. When laid in more than one layer, break joints of succeeding layers of roof insulation with those in preceding layer...
