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MECHARIGALLY ATTACHED ROOFING" °O e °VC 10.Expanded Polystyrene Insulation Fan-fold Re-cover Board E.Protect building surfaces against damage and contamination 3/8" (9.5 mm)with plastic facer meets or exceeds the from roofing work. requirements for ASTM C578,Type IX[min 25 psi(173 F.Where work must continue over completed roof areas,protect the kPa)compressive strength]. finished roofing system from damage. 11.Expanded Polystyrene Insulation Re-cover Board 1/2"(13 G.Deck preparation is the sole responsibility of the building owner mm)with plastic facer meets or exceeds the requirements or roofing contractor.All defects in the roof deck or substrate for ASTM C578,Type IX[min 25 psi(173 kPa)compressive must be corrected before roofing work commences. strength]. H.Refer to GAF Roof Guarantee Program for specific requirements for extended guarantees. 2.10 Base Sheets A.Not required. 3.02 Preparation Of Roofing Area—New&Tear-off Applications 2.11 Slip Sheet/Protection Layer A.Remove all existing roofing materials to the roof decking, A.EverGuard®Polymat slip sheet,3.0 o7,/sq.yd.(102 g/sq.m.). including flashings,metal edgings,drain leads,pipe boots,and pitch pockets,and clean substrate surfaces of all asphalt and B.EverGuard®Polymat cushioning slip sheet,6.0 o7,/sq.yd. adhesive contaminants. (203 g/sq.m). B.Confirm quality and condition of roof decking by visual C.GAF VersaShield®Solo—Fire-Resistant Slip Sheet. inspection and by fastener pull-out testing by an individual trained by the roof fastener manufacturer.GAF recommends these test results to be kept on file as part of the acceptability 2.12 Other Accessories of the substrate surface for a Diamond Pledge—NDL Roof A.The following items may also be required,depending on the Guarantee.Submission of results to GAF is not required. project: C.Secure all loose decking.Remove and replace all 1.Wood Nailers:New wood nailers must be#2 or better lumber. deteriorated decking. Do NOT use asphaltic or creosote-treated lumber. D.Remove abandoned equipment and equipment supports. 2.Roofing Nails:Galvanized or non-ferrous type and size as E.Confirm that height of equipment supports will allow the required to suit application. installation of full-height flashings. 3.Temporary Sealant:Polyurethane foam sealant or similar as F.Refer to Section 3.06 for air/vapor retarders. required to provide temporary watertight sealing of roofing. G.For extended-length guarantees,new roof construction or a tear- 4.Air/Vapor Barrier:Polyethylene sheeting,min.6 mil.for off is required.For tear-offs,remove all existing roofing materials TPO only. to the roof deck.This includes fleshings,metal edgings,drain 5.Fire Barrier:Gypsum panels,min.1/a"(6.3 mm)thick leads,pipe boots,and pitch pockets. (DensDeck®;DensDeck®Prime or SECUROCK—Roof Board). 3.03 Preparation Of Roofing Area—Re-cover Applications PART 3—EXECUTION A.Remove all surfacing and debris from the roof surface. B.Remove blisters and ridges from the roof membrane. 3.01 Site Conditions C.When re-covering over an existing single-ply roof,that roof must A.Obtain verification that the building structure can accommodate be first cut into maximum 10'x 10' (3 m x 3 m)areas before the the added weight of the new roofing system. application of new slip sheet and/or membrane. B.Confirm the adequacy of the new roofing system to provide 1.PVC must be separated from existing PVC roofs and other positive slope to drain.Eliminate ponding areas by the addition types of single-ply membranes and asphaltic membranes of drainage locations or by providing additional pitch to the roof that have active sealants,including asphalt cement,single- surface. ply adhesives,or other non-compatible materials.This C.Prepare substrate surfaces thoroughly prior to application of new can be accomplished by installing a polymat slip sheet, roofing materials.This is particularly important for re-cover and insulation,cover board,or fleece-back PVC membrane. reroofing applications.Providing a smooth,even,sound,clean, 2.Installation over an existing mechanically attached and dry substrate minimizes the likelihood that underlying membrane is only acceptable if all existing fasteners are deficiencies will cause premature deterioration or even failure of flush and do not cause ridging/tenting at the existing the new roofing system. membrane. D.All defects in the roof deck or substrate must be corrected by the D.Remove all existing flashings,including metal edgings,drain responsible parties before new roofing work commences.Verify leads,pipe boots,and pitch pockets,and clean substrate that the deck surface is dry,sound,clean,and smooth,and free surfaces of all asphalt and adhesive contaminants.If the wall/ of depressions,waves,or projections. curb flashings are in good condition and tightly adhered to the substrate,new TPO or PVC flashing materials may be installed over these to a height of 30" (762 mm)without adhesives for 41