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	SECTION 07532
	THERMOPLASTIC MEMBRANE ROOFING (PVC)
	Copyright 2005 - 2009 ARCAT, Inc. - All rights reserved
	** NOTE TO SPECIFIER ** Dow Roofing Systems; single ply roofing systems. . This section is based on the products of Dow Roofing Systems, which is located at: 9 Sullivan Rd. Holyoke, MA 01040-2800 Toll Free Tel: 866-583-2583 Tel: 413-533-8100 Email: request info Web: www.dowroofingsystems.com [ Click Here ] for additional information. Dow Roofing Systems is a leading global provider of thermoplastic roofing membranes, and the inventors of reinforced thermoplastic polyolefin (TPO) roofing membrane. We manufacture and market some of the most technically advanced commercial roofing materials available on the market today. In fact, since the early 1980s, Dow has become the specified choice for building owners, architects, specifiers and roofing contractors in the world for both new construction and re-roofing applications. As the leading manufacturer of TPO based roofing membranes, Dow Roofing Systems has engineered a durable, light-weight roofing membrane system specifically for retrofitting tired, aging, metal roof decks regardless of whether it is a standing seam, flat seam, or corrugated metal roof. Since 1985, Dow Roofing Systems has been a leading industry advocate of the benefits associated with white reflective roofing. Dow has authored many articles on the benefits of white reflective roofing, and a Charter member of the EPA Energy Star Roof Products Program, and a member of the Cool Roof Rating Council. ** NOTE TO SPECIFIER ** This specification is intended for building roofs that have deck structures meeting guidelines herein and have no abnormally severe or unknown environmental exposures, e.g. coastal winds or certain chemicals, except as specifically authorized herein. Applications that involve severe exposures (ASCE Ground Roughness Category D) require review by Dow Roofing Systems Technical Review Dept. before any specification is valid (Reference Table 2, ASCE Exposure Classification Chart). WARNING: Buildings operating with interior positive pressure at the deck require review by DRS Technical Review Dept. before any specification is valid.
	PART 1	GENERAL
	1.1	SECTION INCLUDES
	** NOTE TO SPECIFIER ** Delete items below not required for project.
		A.	Mechanically attached thermoplastic (Viento(tm) PVC) roof membrane systems including insulation, roof edge and accessories.
		B.	Fully adhered thermoplastic (Viento(tm) PVC) roof membrane systems including insulation, roof edge and accessories.
		C.	Fully adhered thermoplastic (Viento(tm) PVC) fleece backed roof membrane systems including insulation, roof edge and accessories.
	1.2	RELATED SECTIONS
	** NOTE TO SPECIFIER ** Delete any sections below not relevant to this project; add others as required.
		A.	Section 06100 - Rough Carpentry: For nailers and roof assembly support.
	** NOTE TO SPECIFIER ** Metal work other than Dow Edge Metal Systems is not covered by Dow for Warranty. Metal work must be secured in a manner approved by DRS, SMACNA guidelines, and/or in compliance with a waterproofing envelope. All metal work that is part of the waterproofing envelope must be sealed, structurally sound, and appropriately anchored to prevent leakage.
		B.	Section 07620 - Sheet Metal and Trim.
	1.3	REFERENCES
	** NOTE TO SPECIFIER ** Delete references from the list below that are not actually required by the text of the edited section.
		A.	ASTM C 578 - Standard Specification for Rigid Cellular Polystyrene Thermal Insulation.
		B.	ASTM C 1177 – Standard Specification for Glass Mat Gypsum Substrate for Use as Sheathing.
		C.	ASTM C 1289 – Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board.
		D.	ASTM D 312 - Standard Specification for Asphalt Used in Roofing.
		E.	ASTM D 4434 - Standard Specification for Poly(Vinyl Chloride) Sheet Roofing.
		F.	FM Global (FMG) 4470 - Approval Standard for Class 1 Roof Covers.
		G.	Underwriters Laboratory UL 790 - Standard Test Methods for Fire Tests of Roof Coverings.
	1.4	SUBMITTALS
		A.	Submit under provisions of Section 01300.
		B.	[ Product Data ]: Manufacturer's data sheets on each product to be used, including:
			1.	Samples and data sheets of materials with approval by manufacturer of all materials not supplied by roofing manufacturer.
			2.	Certification of a minimum of five years experience in the manufacturing of the proposed membrane.
			3.	Certification of ISO 9001 series for manufacturer (Dow Viento(tm) PVC 45 and 60 mil membranes only).
			4.	Certification that proposed assembly including deck is in compliance with FM 4470 – Approval Standard for Class 1 Roof Covers.
			5.	Certification that contractor is authorized to install the proposed assembly.
			6.	Preparation instructions and recommendations.
			7.	Storage and handling requirements and recommendations.
			8.	Installation methods.
		C.	Shop Drawings:
			1.	Outline and size of the roof, location and type of penetrations, perimeter and penetration flashing detail references to manufacture's standard. Details which do not conform to roofing manufacturer's standards shall be identified with separate approval from roofing manufacturer. Details to be employed on the project shall be approved by roofing manufacturer.
		D.	Warranty Certification:
			1.	Submit warranty certification from manufacturer of approval of project design and intent to issue warranty.
	** NOTE TO SPECIFIER ** Delete if not required for mechanically fastened roof systems over gypsum, cementitious woodfiber decks ('Tectum') and light-gauge metal panel roofs.
			2.	Fastener pull tests from an independent testing agency shall be approved by the roofing manufacturer.
	** NOTE TO SPECIFIER ** Delete selection samples if colors have already been selected.
		E.	Selection Samples: For each finish product specified, two complete sets of color chips representing manufacturer's full range of available colors and patterns.
		F.	Verification Samples: For each finish product specified, two samples, minimum size 6 inches (150 mm) square, representing actual product, color, and patterns.
	1.5	QUALITY ASSURANCE
	** NOTE TO SPECIFIER ** Include manufacturer qualifications. Delete if not required.
		A.	Manufacturer Qualifications:
			1.	Manufacturer with a minimum of five years experience in the manufacturing of the proposed roof membrane.
			2.	Manufacturer provided assembly requirements for FM Global (FMG) 4470 Approval Standard for Class 1 Roof Covers, which meet the calculated design pressure requirements of the roofing system as stipulated in FM Global Property Loss Preventions Data Sheets 1-28.
			3.	Dow Viento(tm) PVC 45 and 60 mil membranes are manufactured in a certified ISO 9001 facility.
		B.	Installer Qualifications:
			1.	Roofing contractor shall be authorized by DRS to install assembly. Provide letter on manufacturer's letterhead of authorized status of Contractor.
		C.	Material Qualification:
			1.	Membrane shall be classified by Underwriters Laboratories as a Class A sheathing material for use in construction of Class A roofing assemblies. Shall meet all test requirements for FM Global (FMG) Class 1A fire and wind resistance.
			2.	Shall meet all test requirements for FM Global (FMG) 4470 Approval Standard for Class 1 Roof Covers, which meet the calculated design pressure requirements of the roofing system as stipulated in FM Global Property Loss Preventions Data Sheets 1-28. Test requirements and compliance will be for deck attachment, deck material including grade of steel for metal decks, sheet width and proper attachment with approved fasteners for FM compliance.
	1.6	DELIVERY, STORAGE, AND HANDLING
		A.	Pallets may be stored on the ground in a secure area. If placed on the roof, the load shall not exceed the structural capacity of the deck or crushing resistance of the insulation.
		B.	Packaging shall bear the UL label.
		C.	Store products in manufacturer's unopened packaging until ready for installation.
		D.	Store and dispose of solvent-based materials, and materials used with solvent-based materials, in accordance with requirements of local authorities having jurisdiction.
	1.7	PROJECT CONDITIONS
		A.	Maintain environmental conditions (temperature, humidity, and ventilation) within limits recommended by manufacturer for optimum results. Do not install products under environmental conditions outside manufacturer's absolute limits.
	** NOTE TO SPECIFIER ** Metal work other than Dow Edge Metal Systems is not covered by DRS for Warranty. See General Warranty Section on the DRS Technical Manual CD-ROM or at www.dowroofingsystems.com for more information.
	1.8	WARRANTY
		A.	A manufacturer's representative shall inspect the installation for compliance with manufacturer's standards upon completion of the roofing system.
			1.	Deviations or changes from the contract specification shall have written approval from the roofing manufacturer, for presentation to Architect at completion of roofing system.
		B.	Limited Material Only Warranty: Shall be issued upon acceptance of the roofing system installation.
	** NOTE TO SPECIFIER ** Delete warranty period not required.
			1.	Five (5) year period.
			2.	Ten (10) year period.
			3.	Fifteen (15) year period.
	** NOTE TO SPECIFIER ** Refer to Appendix E, Additional Requirements for Dow 20-year Warranty Systems. Delete if warranty type not required or available for specified system.
			4.	Twenty (20) year period.
		C.	Standard Material and Labor Warranty: Shall be issued upon acceptance of the roofing system installation.
	** NOTE TO SPECIFIER ** Delete warranty periods not required.
			1.	Five (5) year period that covers wind damage up to 70 mph (112.6 k/hr).
			2.	Ten (10) year period that covers wind damage up to 70 mph (112.6 k/hr).
	** NOTE TO SPECIFIER ** Fifteen and Twenty year period not available for VRS System. Delete if not required.
			3.	Fifteen (15) year period that covers wind damage up to 70 mph (112.6 k/hr).
	** NOTE TO SPECIFIER ** Refer to Appendix E, Additional Requirements for Dow 20-year Warranty Systems. Delete if warranty type not required or available for specified system.
			4.	Twenty (20) year period that covers wind damage up to 70 mph (112.6 k/hr).
		D.	No Dollar Limit (NDL) Material and Labor Warranty: Shall be issued upon acceptance of the roofing system installation.
	** NOTE TO SPECIFIER ** Delete warranty periods not required.
			1.	Five (5) year period that covers wind damage up to 70 mph (112.6 k/hr).
			2.	Ten (10) year period that covers wind damage up to 70 mph (112.6 k/hr).
	** NOTE TO SPECIFIER ** Fifteen and Twenty year period not available for VRS System. Delete if not required or available for specified system.
			3.	Fifteen (15) year period that covers wind damage up to 70 mph (112.6 k/hr).
			4.	Twenty (20) year period that covers wind damage up to 70 mph (112.6 k/hr).
	**NOTE TO SPECIFIER**: Total System Warranties require all products during installation to be purchased through Dow Roofing Systems.
		E.	Standard Total System Warranty: Shall be issued upon acceptance of the roofing system installation.
	** NOTE TO SPECIFIER ** Delete warranty periods not required.
			1.	Five (5) year period that covers wind damage up to 70 mph (112.6 k/hr).
			2.	Ten (10) year period that covers wind damage up to 70 mph (112.6 k/hr).
	** NOTE TO SPECIFIER ** Fifteen and Twenty year period not available for VRS System. Delete if not required or available for specified system.
			3.	Fifteen (15) year period that covers wind damage up to 70 mph (112.6 k/hr).
			4.	Twenty (20) year period that covers wind damage up to 70 mph (112.6 k/hr).
		F.	No Dollar Limit (NDL) Total System Warranty: Shall be issued upon acceptance of the roofing system installation.
	** NOTE TO SPECIFIER ** Delete warranty periods not required.
			1.	Ten (10) year period that covers wind damage up to 70 mph (112.6 k/hr).
			2.	Fifteen (15) year period that covers wind damage up to 70 mph (112.6 k/hr).
			3.	Twenty (20) year period that covers wind damage up to 70 mph (112.6 k/hr).
	PART 2	PRODUCTS
	2.1	MANUFACTURERS
		A.	Acceptable Manufacturer: Dow Roofing Systems, which is located at: 9 Sullivan Rd. ; Holyoke, MA 01040-2800; Toll Free Tel: 866-583-2583; Tel: 413-533-8100; Email: marketing@dowroofingsystems.com; Web: www.dowroofingsystems.com
	** NOTE TO SPECIFIER ** Delete one of the following two paragraphs; coordinate with requirements of Division 1 section on product options and substitutions.
		B.	Substitutions: Not permitted.
		C.	Requests for substitutions will be considered in accordance with provisions of Section 01600. All substitutions must meet the quality assurance requirements as specified in sections 1.4B and 1.5 and meet the basis of design for FM Global (FMG) 4470 Approval Standard for Class 1 Roof Covers and UL Class A rated roof and deck assembly.
	2.2	MATERIALS
		A.	Roofing Membrane shall be manufactured by Dow Roofing Systems with the following properties:
	** NOTE TO SPECIFIER ** Delete fleece back if not required.
			1.	Membrane Type:
				a.	Dow Viento(tm) PVC.
				b.	Dow Viento(tm) PVC-Fleece.
			2.	Color:
				a.	White.
				b.	Light gray.
	** NOTE TO SPECIFIER ** Delete thickness not required.
			3.	Membrane Thickness:
				a.	0.45 mil scrim-reinforced Elvaloy(tm)-based sheet.
				b.	0.60 mil scrim-reinforced Elvaloy(tm)-based sheet.
				c.	0.80 mil scrim-reinforced Elvaloy(tm)-based sheet.
			4.	Membranes shall meet the ASTM D-4434-09 Standard Specification for Poly Vinyl Chloride(PVC) based roof membranes.
			5.	Perimeter Sheet specification is defined as membrane with a minimum width of 38.25 inches (972 mm).
			6.	Flashing shall be 0.045 inch (1.15 mm) thick membrane for walls and curbs regardless of roof cover sheet thickness.
			7.	Unreinforced 0.055 inch (1.4 mm) thick, Elvaloy(tm)-based membrane shall be supplied for field-fabricated details not required to be factory formed.
		B.	Insulation:
	** NOTE TO SPECIFIER ** Insulation or protection boards other than those referenced in Appendix MA-A or FA-B must be accepted in writing by Dow. Insulation/underlayment/recover board: DRS supplies a wide range of insulations, underlayments and coverboards to satisfy a broad spectrum of design conditions. Only DRS brand insulation products will be eligible for Total System Warranty coverage. Delete insulation not required.
			1.	Dow Termico Polyisocyanurate Insulation: Closed-cell HCFC FREE polyisocyanurate foam core and integrally laminated to heavy non-asphaltic fiber-reinforced felt facers. Available in flat stock and tapered panels.
	** NOTE TO SPECIFIER ** Delete compressive strength not required.
				a.	Compressive strength: 20 psi (138 kPa).
				b.	Compressive strength: 25 psi (172 kPa).
			2.	Dow Termico(tm) ISO 3000: Closed-cell HCFC FREE polyisocyanurate foam core and integrally laminated to heavy coated-glass facers.
	** NOTE TO SPECIFIER ** Delete compressive strength not required.
				a.	Compressive strength: 20 psi (138 kPa).
				b.	Compressive strength: 25 psi (172 kPa).
			3.	Dow STYROFOAM(tm) extruded polystyrene (XPS): Extruded polystyrene closed-cell foam panel with continuous skin on face and back surface that meets ASTM C-578, Standard Specification for Rigid Cellular Polystyrene Thermal Insulation.
			4.	Dow expanded polystyrene (EPS): - ASTM C578 expanded polystyrene thermal rigid board insulation with a minimum density of 1.25 lb/cf (20 kg/cm).
	** NOTE TO SPECIFIER ** Refer to Product Data Sheets for additional information. Delete if not required.
		C.	Cover Board:
			1.	DensDeck Roof Boards: G-P Gypsum Corporation 1/4 inch (6 mm) DensDeck Prime Roof Board. Glass mat faced gypsum with non-asphaltic, highly filled proprietary heat-cured coating on one side.
		D.	Adhesives, Primers, Caulk, Sealants:
	** NOTE TO SPECIFIER ** Delete if fleece membranes not required.
			1.	Dow Water-Based Fleece Bonding Adhesive: Manufactured for bonding Dow Viento-Fleece membrane in horizontal applications to wood, concrete and approved roof insulation board surfaces.
			2.	Bonding Adhesive: Dow Viento Bonding Adhesive shall be used for bonding all Dow Viento membranes and flashing membranes to wood, metal, masonry, and approved roof insulation board surfaces.
			3.	Dow Non VOC Polyurethane Sealant (NVPS):
			4.	Dow NVPS Sealant shall be used for a water cutoff mastic, sealant to top off pitch boxes, and as an exterior grade caulk for metal work.
			5.	Dow Viento(tm) PVC Cut-Edge Sealant is a solvent-based caulk and shall be used for to seal exposed cut edges of reinforced membrane.
		E.	Dow Insulation Adhesives.
			1.	Dow Insulation Adhesive: A VOC-free, one part, rising, moisture cure foam.
			2.	Dow Olybond 500: A two part, polyurethane low rise foam that is applied in ribbons with appropriate dispensing equipment.
			3.	Dow Olybond Classic: A two part, polyurethane low rise foam that is spray applied to fully cover the substrate.
			4.	Dow INSTA STIK Insulation Adhesive: A single component polyurethane insulation adhesive.
		F.	Related Materials and Accessories:
	** NOTE TO SPECIFIER ** Delete if fleece membranes not required.
			1.	Termination bar: Dow Termination Bar shall be fastened 6 inches (152 mm) o.c.
			2.	Dow Viento(tm) Walkway Roll: Heat welded to the membrane where indicated or required for warranty.
			3.	Dow Viento(tm) PVC Pipe Boots/Vent Gloves: Shall be used for vent stacks and pipes 1 inch (25 mm) to 6 inches (152 mm) diameter.
			4.	Dow Viento(tm) Universal Inside/Outside Corners: Shall be used for flashing for use at outside and inside corners.
			5.	Slip Sheet: Medium to heavy weight (6 oz (170 g) or heavier) nonwoven polyester fabric.
			6.	Flashing Tape and Tape Primer: Shall be used for stripping-in gravel stop and drip edge metal.
		G.	Dow Edge Metal Systems:
			1.	Dow Edge: Shall consist of a heavy formed aluminum base rail with a snap-on cover installed around the outside edge of buildings.
			2.	Dow Fascia: An extruded aluminum bar with a snap-on cover installed around the outside edge of buildings.
	**NOTE TO SPECIFIER:** Delete fascia type not required.
				a.	Standard Fascia.
				b.	HG Fascia.
				c.	Canted Fascia.
			3.	Dow Systems 200.
			4.	Dow Coping Cap.
			5.	Dow Termination Bar- Dow Termination Bar shall be fastened 6-inches (152 mm) o.c.
		H.	Fasteners: Fastener type, length and pull-out resistance shall be approved by roofing manufacturer as supplied by roofing manufacturer. Fastener shall be selected to provide proper attachment for an FM 4470 rated assembly for the calculated design pressures, project deck type and proposed membrane sheet attachment.
			1.	Dow #14 All-Purpose Fastener.
			2.	Dow #12 Insulation Fastener.
			3.	Dow MaxFast, a # 3 phillips pan head, #21 fastener to be used with a 3-inch plate.
				a.	Fasteners: Roofing fastener for membrane attachment.
				b.	Plate: 3-inch (76 mm) diameter.
			4.	Dow Purlin:
				a.	Fasteners.
				b.	Plate: 2-inch (76 mm) diameter.
			5.	Dow DeckGrip:
				a.	DeckGrip Fasteners: a coated #15 fastener.
				b.	DeckGrip Plate: 2-3/8 inch plates.
			6.	Dow PIF: Pre-Assembled Insulation Plate and Fastener - a 3-inch plastic insulation plate with a #12 Fastener.
			7.	Dow ASAP: Pre-Assembled Membrane Seam Plate and Fastener - a 2-inch nylon locking plate with a #14 fastener.
			8.	Dow SW Fastener and Plate Kit: A #21 fastener to be used with a 2-3/8-inch plate.
			9.	Dow CD-10 Concrete Fastener: A non-threaded hammer-in (spike type) fastener for membrane and insulation attachment.
			10.	Dow Masonry Anchor: A hammer in type fastener for securing Dow Termination Bars.
			11.	Dow Hex Insulation: A 2-7/8-inch Hex shaped galvalume coated steel plate.
			12.	Dow 2-inch Barbed Metal Seam Plate: A 2-inch barbed metal seam plate used for membrane attachment.
	PART 3	EXECUTION
	3.1	EXAMINATION
		A.	Do not begin installation until substrates have been properly prepared.
		B.	Nailers and blocking shall be installed level, true to line and elevation, secured to roof structure to resist roof installation and service conditions. Refer to Section 06100.
			1.	Reroofing: Use #2 or better wood treated for rot resistance. Creosote and asphaltic preservatives are not acceptable.
			2.	New Roofing: As specified by architect. A pressure preservative treated wood nailer is recommended. Effective perimeter attachment must be achieved per details.
			3.	All Construction: Nailer shall be anchored with a suitable fastener for the application having a minimum withdrawal resistance of 100 lb (45 kg), staggered 6 inches (152 mm) o.c. within 8 ft (2.4 m) of an outside corner and 12 inches (304 mm) o.c. along other perimeter areas.
			4.	All Construction: Nailer thickness shall be chosen to match the top surface of adjacent construction 1/4 inch (6 mm). This permissible variation shall not contribute to ponding.
			5.	Nailers: Nailers around skylights, curbs, expansion joints, etc., are not required. Use of DRS Plates and Screws anchored to deck 12 inches (304 mm). o.c. through membrane and insulation is acceptable.
		C.	If substrate preparation is the responsibility of another installer, notify Architect of unsatisfactory preparation before proceeding.
	3.2	PREPARATION
		A.	Adhesives, solvents, and caulks as indicated are potentially flammable and/or toxic. Follow precautions indicated on container or packaging labels.
		B.	Surfaces to be bonded shall be dry, clean and free of debris. Suitable surfaces are usually considered to be smooth: solid masonry, wood, and metal, plus insulation boards fastened per the specific manufacturer's recommendations for receiving adhered roofing membranes and accepted by Dow for adhered applications of Dow Viento(tm) PVC membrane.
		C.	All fasteners should be installed with a depth-sensing screw gun to prevent overdriving or under driving.
		D.	Block off or shut down positive pressure building ventilation systems during application to prevent sheet from billowing during application.
		E.	Consideration should be given in the project design to potential safety problems that can precipitate from the smooth surface characteristic of the Dow Viento(tm) PVC sheet. The membrane surface becomes slippery when wet. If access to roof is required, walkway surfaces are highly recommended. In northern climates, sliding snow could create a hazard below and adjacent to the perimeter if a retarding system is not installed on roofs with slopes greater than 2 inches per foot (170 mm/m).
		F.	Job specification and retrofit preparation should always include provisions to ensure positive drainage in all areas. Good roofing practice does not permit uncontrolled, uncollected drainage over the edge of a roof.
		G.	All rooftop mechanical units are to have their condensation lines piped to drains, or off the roof.
		H.	Grease shall not be allowed to accumulate on the roof. If rooftop grease units do not receive continual maintenance they are to have an approved grease containment system specified.
		I.	At the discretion of Dow, excessive patching as a result of damage to the Dow Viento(tm) PVC membrane, or caused by faulty installation, may require total recover in those areas.
		J.	Buildings with canopies or large wall openings, e.g. hangar doors and truck docks or buildings that are otherwise subject to positive pressurization from wind or air handling systems; consult DRS for suitability of application and possible design enhancement requirements.
		K.	Asphalt, coal tar base, oil base or plastic roof cements, and resaturated roof products shall not be used in direct contact with Dow Viento(tm) PVC roof membrane.
	** NOTE TO SPECIFIER ** Vapor retarder is not required for protection of Dow Roofing System membrane. As a guideline, the National Roofing Contractors Association states, "...vapor retarders should be considered for use when both of two conditions are anticipated: (1) the outside mean, average January temperature is below 40 degree F (4.4 degree C), and (2) the expected winter, interior relative humidity is 45 percent or greater." ** NOTE TO SPECIFIER ** Steel deck, wood plank and lightweight cementitious decks: Shall be covered with an approved insulation mechanically fastened or adhered to the deck with DRS approved product (Reference Appendix MA-B, Approved Insulation List & Fastening Rates). Polystyrene boards may require a thermal barrier underlayment over steel decks. Consult manufacturer and local building codes. Delete deck type not required.
		L.	Steel Deck:
			1.	Shall be covered with an approved insulation mechanically fastened to the deck.
		M.	Wood Plank:
			1.	Shall be covered with an approved insulation mechanically fastened or adhered to the deck.
		N.	Lightweight Cementitious Decks:
			1.	Shall be covered with an approved insulation mechanically fastened or adhered to the deck.
	** NOTE TO SPECIFIER ** Concrete, plywood, or flat sheet-metal surface: Plywood must be exterior grade with an A or B finish side up and with no joints gapped greater than 1/4 inch (6 mm). Consideration should be given to installing slip plates over all gapped or uneven joints where membrane seams will cross to minimize welding inconsistency. Thickness, structural grade, fastening, and fire resistance requirements should meet the requirements and recommendations of applicable building codes and the APA and are the responsibility of the owner and the installer. The membrane shall have a fastened expansion joint detail (as per standard DR Detail Drawings) where deck joints exceed 1/4 inch (6 mm) or when crossing a building expansion joint. Delete deck type not required.
		O.	Concrete Deck:
			1.	Concrete shall be cured, and prepared smooth with dust removed.
			2.	Concrete shall be dry, flat, clean, smooth, free of sharp edges and suitable for acceptance of membrane.
		P.	Plywood Deck:
			1.	Plywood must be exterior grade with an A or B finish side up and with no joints gapped greater than 1/4 inch (6 mm).
			2.	Shall be covered with an approved insulation and mechanically fastened or adhered to the deck.
			3.	Shall be dry, flat, clean, smooth, free of sharp edges and suitable for acceptance of approved fully adhered membrane.
	** NOTE TO SPECIFIER ** Reroofing over existing roof: The specifier and/or applicator shall determine the condition of the existing roof. Significantly deteriorated decking must be repaired or replaced, as appropriate. Wet materials (containing free moisture that would evaporate if exposed to atmosphere) must be found and replaced.
		Q.	Reroofing Over Existing Roof:
			1.	Condition of the existing roof must be appropriate to Dow Roofing Systems specifications for reroofing application. Significantly deteriorated decking must be repaired or replaced, as appropriate. Wet materials (containing free moisture that would evaporate if exposed to atmosphere) must be found and replaced.
			2.	Surface shall be dry, smooth and even, blisters cut, and loose aggregate removed.
				a.	Installation of approved insulation or cover board shall comply with manufacturer's standards.
				b.	Barbed metal seam plates and appropriate fastener shall be used to anchor the membrane to the deck at perimeters and penetrations.
	** NOTE TO SPECIFIER ** Delete if fleece membranes not adhered directly to existing roof.
			3.	Fleece membrane shall be directly adhered using hot asphalt (ASTM D-312 type III or IV) to an existing smooth surfaced asphalt built-up roof system (type III or IV asphalt), modified bitumen, and mineral surfaced cap sheet that has been power washed removing all loose granules. Do not adhere fleece membrane directly to low melting point asphalt. Softening point of the asphalt shall not be below 185 degrees F (85 degrees C).
				a.	Barbed metal seam plates and appropriate fastener shall be used to anchor the membrane to the deck at perimeters and penetrations.
		R.	Ponding at the membrane level shall be corrected by improved drainage design as required to eliminate "birdbathing" to less than 4 square feet (.37 square meters), less than 1/2 inch (13 mm) deep areas.
		S.	Prepare surfaces using the methods recommended by the manufacturer for achieving the best result for the substrate under the project conditions.
	3.3	INSTALLATION
		A.	Provide temporary ballast in partially completed sections to control wind effects during construction.
	** NOTE TO SPECIFIER ** Certain insulation types such as polystyrene are not compatible with coal tar pitch. Contact insulation manufacturer for recommendations. Certain polystyrene insulation boards are not suitable for use directly under certain colors of Dow Viento membrane or Viento(tm) fleece membranes and require an overlayment (Reference Appendix MA-B, Approved Insulation List and Fastening Rates). In regard to attachment, compatibility and spanning metal flutes, the manufacturers' instructions or specifications shall determine the suitability for an application, subject to acceptance by DRS. For Material and Labor or Total System Warranty applications, insulation plates and fasteners must be supplied by DRS (Reference Appendix MA-B, Approved Insulation List & Fastening Rates). Delete if not required.
		B.	Insulation Installation:
	** NOTE TO SPECIFIER ** Delete if not required.
			1.	Mechanical Attachment: Insulation boards shall be attached with DRS approved insulation plates and fasteners.
	** NOTE TO SPECIFIER ** As an alternative to mechanical attachment, Dow permits adhering insulation with DRS supplied insulation adhesives (NOT APPROVED FOR STEEL ROOF DECKS). The specific application must be approved in writing by Dow Technical Review Dept. Delete if not required.
			2.	Adhered Insulation with Approved Adhesive: Installation requirements of the adhesive and insulation manufacturer shall be followed. Insulation boards shall be secured sufficiently to conform to the substrate surface geometry.
	** NOTE TO SPECIFIER ** Delete if not required.
			3.	Tapered Insulation:
				a.	Tapered edge strip of high density fiberboard shall be used to provide a smooth transition to the flat areas.
				b.	Insulation boards shall be installed with the longest dimension perpendicular to the direction of the membrane seams whenever possible and installed with end joints staggered. Boards will be butted as closely as possible with no gaps over 1/4 inch (6 mm) and secured to substrate.
	** NOTE TO SPECIFIER ** Delete Fully Adhered Membrane Installation if not required.
		C.	Dow Viento(tm) PVC Fully Adhered Membrane Installation:
			1.	Outside ambient air temperature must be a minimum 40 degrees F (4.4 degrees C) and rising.
			2.	For roofs with interior drainage, start with first sheet centered on drain valley. Fold sheet so that the bottom side half of the full length of sheet is exposed.
	** NOTE TO SPECIFIER ** Delete if bonding adhesive not required.
			3.	Apply a 100 percent continuous coat of bonding adhesive to the exposed bottom side of the sheet and the corresponding substrate area. Adhesive must be spread out by roller as necessary to achieve 100% coverage on the substrate and membrane. Adhesive coverage shall be 60 square feet per gallon for coating substrate and membrane. Adhesive should never be broomed or mopped and must not be cut or extended.
			4.	Allow adhesive to dry until tacky and does not string or stick to a dry finger. When sufficiently dry, carefully unfold the glued portion of the membrane in a rolling motion onto the glued substrate surface, avoiding any wrinkles or air pockets. Immediately roll the adhered area using a weighted pressure roller. Applying pressure with a weighted roller is required to promote full contact of the membrane with adhesive.
			5.	Repeat the procedure for the other half of the sheet.
			6.	For roofs with edge drainage, start at the low edge with the first sheet.
			7.	Lay out the second sheet with a 2 inches (51 mm) overlap on the edge of the first sheet. Perform lap splice. After splice has cooled, completely expose the bottom side of the second sheet by folding back along the splice. Apply adhesive evenly to both underside of membrane and substrate surface, allow to dry to the point where the adhesive is tacky, and carefully turn membrane back onto glued substrate surface avoiding any wrinkles or air pockets. Roll surface using a weighted pressure roller applying pressure to promote full contract. Repeat procedure for each sheet proceeding across roof.
			8.	Lap Splice: Membrane shall be overlapped and hot-air welded without any contaminants (adhesive, dirt, debris, etc.) in the seam.
				a.	The entire lap edge shall be probed with an approved seam probing tool after the seam has cooled completely to verify seam consistency.
				b.	Cut edges shall be caulked by applying sealant.
			9.	At perimeters that are to receive a gravel stop or metal edging, the membrane shall be brought over the outside edge and terminated 12 inches (305 mm) o.c.
			10.	Membrane shall be mechanically attached 12 inches (305 mm) o.c. at all perimeters and at any penetration that has a dimension of 24 inches (610 mm) or greater with fasteners and plates.
	** NOTE TO SPECIFIER ** Delete if fleece not required. Delete if not required.
		D.	Dow Viento Fleece PVC Fully Adhered Membrane Installation:
	NOTE TO SPECIFIER ** Delete section if using Dow Viento(tm) PVC non-fleece membrane.
			1.	Outside ambient air temperature must be a minimum 50 degrees F (4.4 degrees C) and rising. Adhesive should not be stored below 40 degrees F.
			2.	For roofs with interior drainage, start with first sheet centered on drain valley. Fold sheet so that the bottom side half of the full length of sheet is exposed.
			3.	Apply a 100 percent continuous coat of Dow Water-based Fleece Membrane Bonding Adhesive to the area of substrate exposed by folding membrane back. Work evenly across the area to ensure membrane will be rolled into wet adhesive. Reapply adhesive to any areas that have dried or skinned over. Adhesive coverage should be 100 square feet per gallon for coating substrate only. Adhesive must be spread out by roller as necessary to achieve 100% coverage on the substrate. Adhesive should never be broomed or mopped. Adhesive must not be cut or extended.
			4.	Carefully unroll the folded section of fleece membrane and lower it into the glued substrate surface while adhesive is wet, avoiding any wrinkles or air pockets. Immediately broom the adhered area applying pressure to promote full contact.
			5.	Repeat the procedure for the other half of the sheet.
			6.	For roofs with edge drainage, start at the low edge with the first sheet.
			7.	Lay out the second sheet with a 2 inches (51 mm) overlap on the edge of the first sheet. Perform lap splice. After splice has cooled, completely expose the bottom side of the second sheet by folding back along the splice. Apply adhesive evenly to substrate surface only, carefully turn membrane back onto glued substrate surface while adhesive is still wet, avoiding any wrinkles or air pockets. Apply only enough adhesive to an area of the substrate to ensure membrane will be rolled into wet adhesive. Broom surface applying pressure to promote full contract. Repeat procedure for each sheet proceeding across roof.
			8.	Lap Splice: Membrane shall be overlapped and hot-air welded without any contaminants (adhesive, dirt, debris, etc.) in the seam.
				a.	The entire lap edge shall be probed with an approved seam probing tool after the seam has cooled completely to verify seam consistency.
				b.	Cut edges shall be caulked by applying sealant.
			9.	At perimeters that are to receive a gravel stop or metal edging, the membrane shall be brought over the outside edge and terminated 12 inches (305 mm) o.c.
			10.	Membrane shall be mechanically attached 12 inches (305 mm) o.c. at all perimeters and at any penetration that has a dimension of 24 inches (610 mm) or greater with fasteners and plates.
	** NOTE TO SPECIFIER ** Delete if not required.
		E.	Mechanically Attached Membrane Installation:
	** NOTE TO SPECIFIER ** Viento(tm) PVC Mechanically attached systems only. Delete if fully adhered system is specified.
			1.	Perimeter Sheets: defined as Dow Viento(tm) PVC membrane with a maximum sheet width of 38.25-in.
			2.	Perimeter area shall be defined as follows: the extent of perimeter and corner enhancement is based on the smaller value of either 40% of building elevation or 10% of the least horizontal dimension. Perimeter/corner enhancement can never be less than 4% of the least horizontal plan dimension, of 3-ft.
			3.	Perimeter/Corner Enhancement: Perimeter sheets shall be installed at all exposed building perimeters. Perimeter sheets shall be laid out in an approved pattern as shown in Standard Detail DR-602. Provide fasteners at spacing required by manufacturer to comply with wind uplift requirements.
			4.	Appropriate fastener and plate combination shall be installed along the edge of the membrane through the insulation and into the roof deck.
			5.	At perimeters that are to receive a gravel stop or metal edging, membrane shall be brought over the outside edge and terminated 12 inches (610 mm) o.c.
			6.	Field sheets: Membrane shall be unrolled on the area to be covered. Fastener and plate combination shall be installed along the leading edge of the membrane through the insulation and into the roof deck. Adjacent rolls of membrane shall overlap the fastened edge of the installed membrane.
			7.	Lap Splice: Membrane shall be overlapped and hot-air welded without any contaminants (adhesive, dirt, debris, etc.) in the seam.
				a.	The entire lap edge shall be probed with an approved seam probing tool after the seam has cooled completely to verify seam consistency.
				b.	Cut edges shall be caulked by applying sealant.
			8.	Perimeter fastening: membrane secured to perimeter gravel stops or drip edges shall be secured to wood nailers. Membrane shall be fastened at other terminations by using fasteners and seam plates.
		F.	Flashing Installation: Perimeters, curbs, vents, expansion joints, drains, and other details shall be flashed. Under no circumstances shall flashings cover weep holes or any form of through-wall drainage.
			1.	Pipe flashings shall be installed in accordance with manufacturer's detail. Do not flash to lead.
			2.	Expansion joints shall be installed according to manufacturer's detail.
			3.	Roof drains shall be installed in accordance with manufacturer's detail.
	** NOTE TO SPECIFIER ** Delete if not required.
			4.	Fleece backing shall be removed from the back of membrane (or an additional strip of non-fleece membrane added) prior to the completion of any compression seals that use fleece-back membrane.
	** NOTE TO SPECIFIER ** Delete if not required.
			5.	In reroofing, old drains must be cleaned or replaced as needed for clamping detail. All bolts shall be properly secured to supply 100 percent continuous compression of the clamping ring. Remove old leads and packings. Field seams shall not be run through drains. Prefabricated sleeve insert with a clamping ring and backflow seal are acceptable.
	** NOTE TO SPECIFIER ** Metal work other than Dow Edge Metal Systems is not covered by Dow for Warranty. Metal work must be secured in a manner approved by DRS, SMACNA guidelines, and/or in compliance with waterproofing envelope. All metal work that is part of the waterproofing envelope must be sealed, structurally sound, and appropriately anchored to prevent leakage.
		G.	Metal Work Installation:
			1.	Metal work shall be installed in a manner that prevents damage from buckling or wind.
			2.	Metal work shall be sealed and waterproofed.
		H.	Overnight Seal/Temporary Water Stop Installation:
			1.	Water stop shall be made by a sealant method approved by manufacturer.
			2.	Roofing contractor shall coordinate installation to ensure the system is made watertight at the end of each work day.
	** NOTE TO SPECIFIER ** Delete if not required.
		I.	Roof Walkways Installation: When regular and routine roof traffic is anticipated (for example, to service rooftop units), walkway roll is required to be installed over the membrane.
			1.	Membrane shall be clean and dry. Remove any visible dirt and debris.
			2.	Position walkway roll and cut to desired length.
			3.	Walkway shall not cover seams. Walkway roll shall be kept a minimum of 2 inches (51 mm) from the edge of the seam on the bottom sheet of the completed lap and a minimum of 6 inches (152 mm) from the edge of the seam when located on the top sheet of a completed lap.
			4.	Fully weld perimeter of walkway roll to the membrane following standard welding procedures.
	3.4	INSPECTION
		A.	Destructive tests shall be performed daily on a 3 inches (76 mm) wide area of seam weld to verify sufficient peel strength. Verify seam strength and correct procedures and seams that do not provide watertight durable construction.
			1.	A properly welded seam will have membrane delamination from scrim prior to weld failure.
			2.	Additional destructive tests on welds shall be conducted for the first seam of the day, the first seam after the robot welder has been allowed to cool down, and after any extreme changes in weather conditions.
		B.	Upon completion of the installation, an inspection will be performed by a representative of the roofing manufacturer to ascertain that the roofing membrane system has been installed according to DRS approved specifications and details. Upon approval of the project, a Warranty shall be written.
	3.5	PROTECTION
		A.	Protect installed products until completion of project.
		B.	Touch-up, repair or replace damaged products before Substantial Completion.
	END OF SECTION