2.3.1 The Contractor shall replace the existing deteriorated bitumen roof with a 50-Mil fully warranted white Duro-Last PVC Membrane Roofing system. Installation shall include 4” Dura-Last fasteners, 2-piece white Dura-Last compression metal, custom Dura-Last PVC stack flashings, termination bars, new 4” drains and covers, 2-way breather vents (1 per 10 sq. ft.), plus pourable pitch pocket filler. The Contractor shall execute the roof replacement per the following tasks: 2.3.1.1 Tarp and protect landscaping, sidewalks, including catwalk areas to the right and left of the roof, as needed prior to beginning roof work. 2.3.1.2 Remove all existing debris, existing flat roof system, and prepare roof surface for Dura-Last PVC installation. 2.3.1.3 Install Duro-Last slip sheet over the existing modified bitumen roofing material and under the existing HVAC lumber curbs; secure with cleats per manufacturer guidelines. 2.3.1.4 Install new white PVC Duro-Last membrane and secure with 4" Dura-Last fasteners and plates. 2.3.1.5 All deck sheets and parapets shall be pulled tight and installed with 2-piece Duro-Last compression metal (4” exposure, white) as wrinkle free as possible. 2.3.1.6 Terminate new PVC membrane with termination bar behind the aluminum siding at full perimeter of flat roofing areas and seal. 2.3.1.7 Replace all existing center drain assemblies with new 4" drains and new covers. 2.3.1.8 Install 2-way breather vents (1 per 10 square feet.) per manufacturer guidelines. 2.3.1.9 All structural steel penetrations shall include custom Dura-Last PVC stack flashings and welds per manufacturer guidelines. 2.3.1.10 All fabricated and manufactured seams shall be heat welded at least 1 ½ inches per manufacturer recommendations. 2.3.1.11 All seams shall be cleaned using acetone or a similar approved cleaning agent, if applicable. 2.3.1.12 Replace all pitch pockets at HVAC units and seal with pourable pitch pocket filler.
