Dow Roofing Systems Roof Garden Assembly Specification

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SECTION 07545

ROOF GARDEN ASSEMBLY

** 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 the world over for both new construction and re-roofing applications.

Dow Roofing Systems brings its vast experience in containment membranes, roofing construction and European green roofs to the United States with the introduction of the Dow GardenTop System. The Dow GardenTop System combines superior roofing membrane, insulation components and water management technology to deliver maximum performance, design flexibility and installation efficiency. There are two Dow GardenTop System options: intensive and extensive. The difference between the two is the depth of growing medium contained in the system. An intensive system, or "deep" system, has soil depth greater than six inches (152 mm). The extensive system uses less growing medium, between two and six inches (52 mm and 152 mm), to support the plant life.

Dow has designed both systems for installation with our Dow Tiempo™ or Dow Viento™ membranes, complimented by a full line of accessory products that complete the Dow GardenTop assembly.

The intensive system places the loose laid waterproofing membrane directly over a high load capacity roof deck and the remaining system components, such as the insulation and drainage system, between it and the growing medium. High density, closed cell insulation is used. A Dow GardenTop Drain multi component drainage system facilitates the vertical and horizontal flow of water through the roof assembly to the roof drains and provides air movement across the membrane surface.

An adhered roof assembly is the basis of the extensive system. High density DensDeck Prime Roof Board provides a durable substrate for the membrane. Dow GardenTop Drain is placed on the membrane to provide: a high volume exit for water, reservoirs for water retention and an EPA certified fabric that protects against root intrusion. The shallow growing medium and plantings complete the extensive system.

** 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 Dow 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.

Intensive roof garden systems including insulation, membrane, drainage layer components, roof edge and accessories.

Extensive roof garden systems including insulation, membrane, drainage layer components, roof edge and accessories.

1.2

RELATED SECTIONS

** NOTE TO SPECIFIER ** Delete any sections below not relevant to this project; add others as required.

Section 02900 - Landscaping: For growing medium and plantings.

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's Warranty. Metal work shall be secured in a manner approved by Dow and/or in accordance with SMACNA guidelines to prevent damage from buckling, or wind exposure. All metal work that is part of the waterproofing envelope shall be sealed, structurally sound, and appropriately anchored to prevent leakage.

Section 07620 - Sheet Metal and Trim: For metal flashings, counter flashings, roof edge and trim associated with the garden roof assembly.

1.3

REFERENCES

** NOTE TO SPECIFIER ** Delete references from the list below that are not actually required by the text of the edited section.

ASTM C 140 - Standard Test Methods for Sampling and Testing Concrete Masonry Units and Related Units.

ASTM 578 - Standard Specification for Rigid Cellular Polystyrene Thermal Insulation.

ASTM C 1289 - Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board.

ASTM D 312 - Standard Specification for Asphalt Used in Roofing.

ASTM D 448 - Standard Classification for Sizes of Aggregate for Road and Bridge Construction.

ASTM D 4434 - Standard Specification for Poly(Vinyl Chloride) Sheet Roofing.

ASTM D 6878 - Standard Specification for Thermoplastic Polyolefin Based Sheet Roofing.

1.4

SUBMITTALS

Submit under provisions of Section 01300.

Product Data: Manufacturer's data sheets on each product to be used, including:

Samples and data sheets of materials, with approval by roofing manufacturer, of all materials not supplied by roofing manufacturer.

Preparation instructions and recommendations.

Storage and handling requirements and recommendations.

Installation methods.

Shop Drawings:

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.

** NOTE TO SPECIFIER ** For a Limited Membrane Material-Only Warranty, the Request for Membrane Warranty form is the only submittal required. Delete if not required.

Certification: A structural engineer or owner's representative shall verify in writing to roofing manufacturer the structure's ability to safely support the membrane waterproofing system and overburden materials.

Warranty Certification:

Submit warranty certification from manufacturer of approval of project design and intent to issue warranty.

** NOTE TO SPECIFIER ** Delete selection samples if colors have already been selected.

Selection Samples: For each finish product specified, two complete sets of color chips representing manufacturer's full range of available colors and patterns.

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.

Manufacturer Qualifications:

Installer Qualifications:

Roofing contractor shall be authorized by Dow to install assembly.

Material Qualification:

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.

** NOTE TO SPECIFIER ** Include a mock-up if the project size and/or quality warrant taking such a precaution. The following is one example of how a mock-up on a large project might be specified. When deciding on the extent of the mock-up, consider all the major different types of work on the project.

Mock-Up: Provide a mock-up for evaluation of surface preparation techniques and application workmanship.

Finish areas designated by Architect.

Do not proceed with remaining work until workmanship, color, and sheen are approved by Architect.

Refinish mock-up area as required to produce acceptable work.

1.6

DELIVERY, STORAGE, AND HANDLING

Packaging shall bear the UL label.

Store products in manufacturer's unopened packaging until ready for installation.

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

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 Dow Warranty. See General Warranty section on the Dow Technical Manual CD-Rom for more information. Refer to Appendix E, Additional Requirements for Dow 20-year Warranty Systems.

1.8

WARRANTY

The cost of removal and/or replacement of the overburden components of the roof garden assembly necessary for the investigation of leaks shall be borne by the Building Owner and is not covered by the warranty.

A manufacturer's representative shall inspect the installation for compliance with manufacturer's standards upon completion of the roofing system.

Deviations or changes from the contract specification shall have written approval from the roofing manufacturer, for presentation to Architect at completion of the roof garden roofing system.

** NOTE TO SPECIFIER ** Refer to Appendix E, Additional Requirements for Dow 20-year Warranty Systems. Delete if not required.

Standard System Warranty: will be issued upon acceptance of the roofing system installation.

** NOTE TO SPECIFIER ** Delete warranty periods not required.

Five (5) year period that covers wind damage up to 70 mph (113 k/hr).

Ten (10) year period that covers wind damage up to 70 mph (113 k/hr).

Fifteen (15) year period that covers wind damage up to 70 mph (113 k/hr).

Twenty (20) year period that covers wind damage up to 70 mph (113 k/hr).

** NOTE TO SPECIFIER ** Refer to Appendix E, Additional Requirements for Dow 20-year Warranty Systems. Delete if not required.

Total System Warranty: will be issued upon acceptance of the roofing system installation.

** NOTE TO SPECIFIER ** Delete warranty periods not required.

Five (5) year period that covers wind damage up to 70 mph (113 k/hr).

Ten (10) year period that covers wind damage up to 70 mph (113 k/hr).

Fifteen (15) year period that covers wind damage up to 70 mph (113 k/hr).

Twenty (20) year period that covers wind damage up to 70 mph (113 k/hr).

PART 2

PRODUCTS

2.1

MANUFACTURERS

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: request info; 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.

Substitutions: Not permitted.

Requests for substitutions will be considered in accordance with provisions of Section 01600.

** NOTE TO SPECIFIER ** The Dow Extensive Garden Roof system should only be applied on structures with a roof slope of 2 in 12 or less. This system is applicable for building roofs that have steel or structural concrete deck structures capable of safely supporting the anticipated roof loads, meet the guidelines herein and have no abnormally severe or unknown environmental exposures, except as specifically authorized herein. Delete if not required.

2.2

EXTENSIVE ROOF GARDEN SYSTEM

System: Furnish and install a Dow Extensive GardenTop Roof System (shallow to medium soil depth)

** NOTE TO SPECIFIER ** The Dow GardenTop Intensive Roof System should only be applied on structures with a roof slope of 2 in 12 or less. If the overburden will not be applied immediately and the waterproofing system is to be left exposed for a period of time, it will be necessary to use the Fully Adhered variation of this Specification. Delete if not required.

2.3

INTENSIVE ROOF GARDEN SYSTEM

System: Furnish and install a Dow Intensive Garden Roof System.

The system shall be loose-laid with the overburden components applied immediately after the completion of the waterproofing and quality control procedures. The weight of overburden shall be a minimum of 10 lb/sf (479 Pa) over the entire roof area.

2.4

MATERIALS

** NOTE TO SPECIFIER ** Membranes listed are applicable to both GardenTop Systems.

Membrane shall be 0.060 inch (1.5 mm) or 0.080 inch (2 mm) nominal thickness overall, or 0.060 inch (1.5 mm) thick membrane with fleece backing, scrim-reinforced, hot-air weldable sheet material as indicated below. Face color shall be standard white.

** NOTE TO SPECIFIER ** Delete membrane not required.

Dow Tiempo+ (TPO): Ethylene Propylene-based sheet roofing manufactured in accordance with ASTM D-6878.

Dow Tiempo+-Fleece: Ethylene Propylene-based sheet roofing with a factory laminated fleece backing, manufactured in accordance with ASTM D-6878.

Dow Viento: PVC Elvaloy (KEE)-based sheet roofing manufactured in accordance with ASTM D-4434.

Dow Viento-Fleece: Elvaloy (KEE)-based sheet roofing with a factory laminated fleece backing, manufactured in accordance with ASTM D-4434.

Flashing shall be .055 inch (1.4 mm) thick membrane for walls and curbs regardless of roof cover sheet thickness.

Unreinforced .055 inch (1.4 mm) thick, membrane shall be supplied for field-fabricated details not required to be factory formed.

Related Materials and Accessories:

Adhesives, sealants, primers and caulks as required and supplied by manufacturer for membrane.

** NOTE TO SPECIFIER ** Extensive GardenTop System only. Delete if not required.

Insulation Adhesive: Dow Insulation Adhesive is a VOC-free, one-part, rising, moisture-cure foam adhesive and shall be used for bonding most insulation and recover boards to most flat roofing decks. Dow-OlyBond 500 and Dow-OlyBond Classic are dual component, rising, chemical cure polyurethane adhesives that are ribbon or spray applied and shall be used for bonding most insulation and recover boards to most flat roofing decks.

** NOTE TO SPECIFIER ** Intensive GardenTop System only. Delete if not required.

Dow Protection Fabric: 6 oz/sy, 120 mil (3 mm) thickness, needle-punched polyester fabric used as a protection layer between structural and cellular concrete substrates and the Dow waterproofing membrane.

Termination bar: Dow Termination Bar shall be fastened 6 inches (152 mm) o.c.

Edge Metal Systems: Dow Edge Metal shall be installed per standard DR details.

Prefabricated Pipe Boots: Shall be used for vent stacks and pipes 1 inch (25 mm) to 6 inches (152 mm) diameter.

Prefabricated Corners: Shall be used for flashing for use at outside and inside corners.

Flashing Tape: Shall be used for stripping-in gravel stop and drip edge metal.

** NOTE TO SPECIFIER ** Extensive GardenTop System only. Delete if not required.

Insulation and Membrane Fasteners: Fastener type, length and pull-out resistance shall be approved by roofing manufacturer as supplied by roofing manufacturer.

** NOTE TO SPECIFIER ** Insulation or protection board shall be accepted in writing by Dow. Insulation/underlayment/recover board: Dow supplies a wide range of insulations, underlayments and coverboards to satisfy a broad spectrum of design conditions. Only Dow brand insulation products will be eligible for Total System Warranty coverage; products other than Dow will incur a premium warranty fee. (Reference Appendix MA-B, Dow Approved Insulation List and Fastening Rates for Mechanically Attached Systems) Delete insulation not required.

2.5

INSULATION

** NOTE TO SPECIFIER ** Extensive System: Rigid insulation and cover board shall be provided by Dow. A cover board described herein shall always be used over rigid insulation boards (polyisocyanurate, extruded polystyrene and expanded polystyrene) but is not required over approved cellular insulating concrete.
** NOTE TO SPECIFIER ** To resist the long term effects of the overburden loads associated with Intensive Systems a cover board of the type and thickness described below is required over any of the insulation products specified herein with a compressive strength less than 25 psi (170 kPa).

Insulation: Rigid Insulation and/or cover board shall be provided by roofing manufacturer. Insulation boards shall be a minimum of 1.5 inches (38 mm) thick.

** NOTE TO SPECIFIER ** Acceptable for systems with an overburden weight of 30 lb/ft (145 kg/m) maximum. A cover board is required over this product. Delete if not required.

Dow Termico Polyisocyanurate Insulation Closed-cell HCFC free "Green" polyisocyanurate foam core with integrally laminated heavy non-asphaltic, fiber-reinforced felt facers meeting Federal Specification HH-I-1972/2, Class 1 and ASTM C1289-95, Type II.

** NOTE TO SPECIFIER ** Delete if not required.

20 psi (140 kPa) compressive strength rating

** NOTE TO SPECIFIER ** Delete if not required.

25 psi (170 kPa) compressive strength rating.

** NOTE TO SPECIFIER ** Acceptable for systems with an overburden weight of 30 lb/ft (145 kg/m) maximum. A cover board is required over this product. Delete if not required.

Dow ISO 3000 Closed-cell HCFC free "Green" polyisocyanurate foam core with integrally laminated heavy coated-glass facers meeting Federal Specification HH-I-1972/2, Class 1 and ASTM C1289-95, Type II.

** NOTE TO SPECIFIER ** Delete if not required.

20 psi (140 kPa) compressive strength rating

** NOTE TO SPECIFIER ** Delete if not required.

25 psi (170 kPa) compressive strength rating.

** NOTE TO SPECIFIER ** Dow Extruded Polystyrene with a minimum compressive strength of 25 psi (170 kPa) is the only insulation product approved for use in a protected membrane assembly (insulation installed above the waterproofing membrane) for Extensive GardenTop Systems.
** NOTE TO SPECIFIER ** Dow Extruded Polystyrene with a minimum compressive strength of 40 psi (275 kPa) is the only insulation product approved for use in a protected membrane assembly (insulation installed above the waterproofing membrane) for Intensive GardenTop Systems.
** NOTE TO SPECIFIER ** Delete if not required.

Dow extruded polystyrene (XPS) boards meeting ASTM C578-98

** NOTE TO SPECIFIER ** Acceptable insulation for extensive roof garden applications only. Delete if not required.

15 psi (103 kPa) compressive strength product.

** NOTE TO SPECIFIER ** Acceptable insulation for systems with an overburden weight of 55 lb/ft (270 kg/m) maximum. Delete if not required.

25 psi (170 kPa) compressive strength product.

** NOTE TO SPECIFIER ** Delete if not required.

40 psi (275 kPa) compressive strength product for medium to heavy-weight systems.

** NOTE TO SPECIFIER ** Delete if not required.

60 psi (413 kPa) compressive strength product for heavy-weight systems.

** NOTE TO SPECIFIER ** Delete if not required.

Dow Expanded Polystyrene (EPS) boards meeting ASTM C578-04a

** NOTE TO SPECIFIER ** Extensive use only. A cover board is required over this product. Delete if not required.

Type II, minimum density of 1.35 pcf (22 kg/m 3) and a compressive strength of 18 psi (124 kPa).

** NOTE TO SPECIFIER ** A cover board is required over this product. Delete if not required.

Type II, nominal density 1.5 pcf (24 kg/m 3) and a compressive strength of 18 psi (124 kPa).

** NOTE TO SPECIFIER ** Acceptable for systems with an overburden weight of 55 lb/ft (270 kg/m) maximum. Delete if not required.

Type IX, nominal density 2.0 pcf (32 kg/m 3) and a compressive strength of 25 psi (170 kPa).

** NOTE TO SPECIFIER ** Refer to Dow Product Specification Data Sheets for additional information. Delete if not required.

DensDeck Roof Boards: Cover board.

** NOTE TO SPECIFIER ** Delete roof board and thickness not required.

G-P Gypsum Corporation: Nonstructural, glass mat faced gypsum panel with water-resistant core. 1/4 inch (6 mm) DensDeck Roof Board.

G-P Gypsum Corporation: Nonstructural, glass mat faced gypsum panel with water-resistant core. 1/2 inch (13 mm) DensDeck Roof Board.

G-P Gypsum Corporation: Nonstructural, glass mat faced gypsum panel with water-resistant core. 5/8 inch (16 mm) DensDeck Type X Roof Board.

** NOTE TO SPECIFIER ** Delete roof board and thickness not required.

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.

G-P Gypsum Corporation: 1/2 inch (13 mm) DensDeck Prime Roof Board. Glass mat faced gypsum with non-asphaltic, highly filled proprietary heat-cured coating on one side.

G-P Gypsum Corporation: 5/8 inch (16 mm) DensDeck Prime Roof Board Type X. Glass mat faced gypsum with non-asphaltic, highly filled proprietary heat-cured coating on one side.

** NOTE TO SPECIFIER ** Delete roof board and thickness not required.

G-P Gypsum Corporation: 1/4 inch (6 mm) DensDeck DuraGuard,. Glass mat faced gypsum panel with blue low-perm, durable, integrated-coating on one side and coated glass mat on the back.

G-P Gypsum Corporation: 1/2 inch (13 mm) DensDeck DuraGuard. Glass mat faced gypsum panel with blue low-perm, durable, integrated-coating on one side and coated glass mat on the back.

G-P Gypsum Corporation: 5/8 inch (16 mm) DensDeck DuraGuard. Glass mat faced gypsum panel with blue low-perm, durable, integrated-coating on one side and coated glass mat on the back.

** NOTE TO SPECIFIER ** Delete if not required.

Cellular Insulating Concrete shall be composed of Type I Portland cement, a foaming agent and water with a minimum cast density of 30 lb/cf (480 kg/cu. m) and a minimum 200 psi (1.4 mPa) compressive strength.

** NOTE TO SPECIFIER ** Delete if not required.

Extensive Garden Roof Composite Drainage Panels: Used as a protection layer, root barrier and water retaining layer and is composed of a geotextile filter fabric that is factory laminated to a molded polystyrene core.

** NOTE TO SPECIFIER ** Refer to manufacturer literature for drainage performance. Delete type not required.

Dow GardenTop Drain 50RS: 7/16 inch (11 mm) thick core, 15,000 psf (73200 kg/sq. m) compressive strength, with a top layer of needle-punched 5.6 oz/sf polypropylene fabric treated with RootShield to prevent root penetration and a 4.0 oz/sf needle-punched polypropylene separation layer on the bottom.

Dow GardenTop Drain 100RS: 1.0 inch (25 mm) thick core, 9,500 psf (46360 kg/sq. m) compressive strength, with needle-punched 5.6 oz/sf polypropylene fabric treated with RootShield to prevent root penetration and 4.0 oz/sf needle-punched polypropylene separation layer.

** NOTE TO SPECIFIER ** Delete if not required.

Intensive Garden Roof Composite Drainage Panels: Used as a protection layer/water retainage layer and is composed of a molded polystyrene core with or without a factory laminated filter fabric layer.

Dow Garden Roof Drain 200H: 0.25 inch (6 mm) thick, 10,800 psf (52,704 kg/sq. m) compressive strength, core-only configuration specifically designed for horizontal applications.

Dow Garden Roof Drain 200V: 0.25 inch (6 mm) thick core, 10,800 psf (5,2704 kg/sq. m) and a needle-punched polypropylene fabric with a flow capacity of 9 gal/min/ft (per unit width). Specifically designed for vertical applications.

Dow Garden Roof Drain 650: 7/16 inch (11 mm) thick core, 21,000 psf (102,480 kg/sq. m) compressive strength, and a needle-punched polypropylene fabric with a flow capacity of 18 gal/min/ft (per unit width).

** NOTE TO SPECIFIER ** Delete if specified in other sections of the project manual.

Hardscape Items:

** NOTE TO SPECIFIER ** Delete items not required.

Architectural Plaza Pavers: Precast concrete plaza paver units nominal size 18 inches by 18 inches by 1.75 inches (457 mm by 457 mm by 44 mm) or 24 inches by 24 inches by 2 inches (610 mm by 610 mm by 51 mm), weighing a minimum of 20 psf (98 kg/sq. m) with a minimum compressive strength of 6500 psi (44850 kPa) (per ASTM C 140).

Paver Pedestal System: Type and design as recommended by the plaza paver manufacturer. Pedestals serve to elevate the surface of the pavers above the roof membrane (and/or drainage composite, insulation, etc,) and to promote positive drainage for protection against the effects of freeze/thaw.

Stone Ballast: Nominal 3/4 inch (19 mm) to 1-1/2 inches (38 mm) diameter (ASTM D 448 #4 gradation) rounded washed stone applied at a minimum of 10 pounds per square foot (49 kg/sq. m).

Additional Items: Planters, trays, concrete curbs, landscape timber or other landscape products suitable for this application. Used to transition between growing media, roof top projections and other Garden Roof components. Type and amounts as indicated by specifier.

** NOTE TO SPECIFIER ** Delete if specified in other sections of the project manual.

Softscape Items:

** NOTE TO SPECIFIER ** Delete items not required.

Growing medium: Lightweight growing medium consisting of high-quality compost and recycled materials engineered to be water permeable; to retain water and air; to resist rot, heat, flying sparks, frost and shrinkage; to provide nutrients appropriate to the chosen plants; and to provide a rooting medium. Type and amounts as indicated.

Sedum: Plant species used as for ground cover. Size, shapes, color and growth patterns as indicated.

PART 3

EXECUTION

** NOTE TO SPECIFIER ** Adhesives, solvents, and caulks as indicated are extremely flammable and/or toxic. Follow precautions indicated on container or packaging labels.
** NOTE TO SPECIFIER ** 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 membrane.
** NOTE TO SPECIFIER ** Consideration should be given in the project design to potential safety problems that can precipitate from the smooth surface characteristic of the Dow 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).

3.1

EXAMINATION

Roof top mechanical units shall have their condensation lines piped to drains, or off the roof.

Grease shall not be allowed to accumulate on to the roof. If roof top grease units are not to receive continual maintenance program, they are to have an approved grease containment system.

Do not begin installation until substrates and roof equipment have been properly prepared.

** NOTE TO SPECIFIER ** Reroofing: Use #2 or better wood treated for rot resistance. Creosote and asphaltic preservatives are not acceptable.
** NOTE TO SPECIFIER ** New roofing: A pressure preservative treated wood nailer is recommended. Effective perimeter attachment shall be achieved per details.
** NOTE TO SPECIFIER ** 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.
** NOTE TO SPECIFIER ** 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.
** NOTE TO SPECIFIER ** Nailers around skylights, curbs, expansion joints, etc., are not required. Use of Dow Plates and Screws anchored to deck 12 inches (304 mm). o.c. through membrane and insulation is acceptable.

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.

If substrate preparation is the responsibility of another installer, notify Architect of unsatisfactory preparation before proceeding.

3.2

PREPARATION

Surfaces to be bonded shall be dry, clean and free of debris.

Shut down roof top fresh-air intakes and secure ventilation systems that recycle air through open cavities between ceilings and roof deck. Operation of HVAC equipment shall be coordinated with building owner to ensure fresh air intake vents do not operate in the vicinity of the adhesive application to prevent vapors from entering the building.

Block off or shut down positive pressure building ventilation systems during application to prevent sheet from billowing during application.

For buildings with canopies or large wall openings, e.g. hangar doors and truck entrances or docks, which are subject to positive pressurization from wind or from air handling systems, consult manufacturer for suitability of application and possible design enhancement requirements.

Ensure positive drainage in all areas. Do not allow uncontrolled, uncollected drainage over the edge of a roof.

Prepare surfaces using the methods recommended by the manufacturer for achieving the best result for the substrate under the project conditions.

Overnight Seal/Temporary Water Stop Installation:

Water stop shall be made by a sealant method approved by manufacturer.

Roofing contractor shall coordinate installation to ensure the system is made watertight at the end of each work day.

Roof surface shall be free of ponded water, snow, ice, and all debris in order to provide proper uniform surface for installation of overburden.

Protect the waterproofing system as necessary to prevent damage during the application of overburden/backfilling operations, roof top traffic and/or the activities of other trades.

** NOTE TO SPECIFIER ** Delete if not required.

3.3

INTENSIVE INSTALLATION

** 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."

Concrete Deck:

Concrete shall be fully cured, and prepared smooth with dust removed.

Concrete shall be dry, flat, clean, smooth, free of sharp edges and suitable for acceptance of membrane.

An approved insulation or cover board or a layer of Dow Protection Fabric is required prior to installing membrane over concrete unless Dow fleece-backed membrane is used.

** NOTE TO SPECIFIER ** Delete if not required.

Cover Board and Insulation Installation:

Minimum thickness: 1.5 inches (38 mm) insulation boards. Provide tapered insulation where indicated.

Minimum thickness: 1/4 inches (6 mm) cover boards

Approved insulation boards shall be installed end joints staggered. Boards will be butted as closely as possible with no gaps over 1/4 inch (6 mm).

Membrane Installation:

** NOTE TO SPECIFIER ** Not required if deck insulation or cover board specified. Delete if not required.

Dow Protection Fabric: After concrete deck has been prepared, unroll protection fabric (without introducing wrinkles) over area where waterproofing is to be applied. Fold and/or cut fabric to conform to surface geometry and overlap adjacent sheets a minimum of 4 inches (102 mm). Fabric should be installed within 1/4 inch (6 mm). of any roof top projection (pipes, curbs, etc.).

Field sheet membrane shall be unrolled on the area to be covered, with a minimum 2-inches (52 mm) overlap from the edge of the previous roll of membrane.

Lap Splice: Membrane shall be overlapped and hot-air welded without any contaminants (adhesive, dirt, debris, etc.) in the seam.

The entire lap edge shall be probed with an approved seam probing tool after the seam has cooled completely to verify seam consistency.

Cut edges shall be caulked by applying sealant.

** NOTE TO SPECIFIER ** Delete if fleece membrane not required.

For areas of fleece membrane that do not have a selvage edge, weld a cover strip of standard 6 inches (152 mm) wide reinforced non fleece membrane.

** NOTE TO SPECIFIER ** The point where two perpendicular lap seams intersect is called a "T-seam" and if T-seams are not properly welded, a seam void may result.

T-Seams

For .060 inch (1.5 mm) membrane, T-seams shall be properly creased in at the step-off area, using a hand roller. For T-seam locations that have not been welded properly, a patch is required. Patches shall be a minimum of 4 inches (102 mm). in diameter and can be either .045 inch (1.1 mm) reinforced Dow EP membrane or .055 inch (1.4 mm). unsupported membrane.

For Dow .080 inch (2 mm) thick membrane, a patch is required on all T-seam locations.

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.

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.

3.4

EXTENSIVE INSTALLATION

Concrete Deck:

Concrete shall be fully cured, and prepared smooth with dust removed.

Concrete shall be dry, flat, clean, smooth, free of sharp edges and suitable for acceptance of membrane.

** NOTE TO SPECIFIER ** Steel deck and lightweight cementitious decks shall be covered with an approved insulation mechanically fastened or adhered to the deck with Dow 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 if not required.

Steel Deck:

Shall be covered with an approved insulation mechanically fastened or adhered to the deck.

** NOTE TO SPECIFIER ** Delete if not required.

Lightweight Cementitious Decks:

Shall be covered with an approved insulation mechanically fastened or adhered to the deck.

** NOTE TO SPECIFIER ** 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 Dow. For Total System Warranty applications, insulation plates and fasteners shall be supplied by Dow (Reference Appendix MA-B, Approved Insulation List & Fastening Rates). Delete if not required.

Insulation Installation:

** NOTE TO SPECIFIER ** Delete if not required.

Mechanical Attachment: Insulation boards shall be attached with FMG and manufacturer-approved insulation plates and fasteners.

Fasteners shall be installed with a depth sensing screw gun to prevent overdriving or underdriving. The ASAP and PIF adapter tools shall be used for the installation of Dow ASAP and PIF fasteners.

** NOTE TO SPECIFIER ** As an alternative to mechanical attachment, Dow permits adhering insulation with Dow Insulation Adhesive and other approved insulation adhesives. The specific application shall be approved in writing from the adhesive manufacturer and be approved by Dow Technical Review Dept. Delete if not required.

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 ** As an alternative to mechanical attachment, Dow permits adhering insulation with hot steep asphalt (ASTM D-312 Type III or IV). The specific application shall be approved in writing from the insulation board manufacturer and be approved by Dow Technical Review Dept. All temperature requirements and application procedures shall be followed. Insulation boards shall be secured sufficiently to conform to the substrate surface geometry. Delete if not required.

Adhered Insulation with Asphalt: Adhere insulation with hot steep asphalt (ASTM D-312 Type III or IV). Temperature requirements and application procedures shall be followed. Insulation boards shall be secured to conform to the substrate surface geometry.

** NOTE TO SPECIFIER ** Delete if not required.

Tapered Insulation:

Tapered edge strip of high density fiberboard shall be used to provide a smooth transition to the flat areas.

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.

Fully Adhered Membrane Installation:

Outside ambient air temperature shall be a minimum 50 degrees F (10 degrees C) and rising.

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.

For roofs with edge drainage, start at the low edge with the first sheet.

Adhere first sheet to substrate with manufacture provided membrane adhesive.

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 and carefully turn membrane back onto substrate surface avoiding any wrinkles or air pockets. Repeat procedure for each sheet proceeding across roof.

Lap Splice: Membrane shall be overlapped and hot-air welded without any contaminants (adhesive, dirt, debris, etc.) in the seam.

The entire lap edge shall be probed with an approved seam probing tool after the seam has cooled completely to verify seam consistency.

Cut edges shall be caulked by applying sealant.

** NOTE TO SPECIFIER ** Delete if fleece membrane not required.

For areas of fleece membrane that do not have a selvage edge, weld a cover strip of standard 6 inches (152 mm) wide reinforced non fleece membrane.

** NOTE TO SPECIFIER ** The point where two perpendicular lap seams intersect is called a "T-seam" and if T-seams are not properly welded, a seam void may result.

T-Seams

For .060 inch (1.5 mm) membrane, T-seams shall be properly creased in at the step-off area, using a hand roller. For T-seam locations that have not been welded properly, a patch is required. Patches shall be a minimum of 4 inches (102 mm). in diameter and can be either .045 inch (1.1 mm) reinforced Dow Tiempo membrane or .055 inch (1.4 mm). unsupported membrane.

For Dow .080 inch (2 mm) thick membrane, a patch is required on all T-seam locations.

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.

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.

3.5

METAL WORK

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.

Pipe flashings shall be installed in accordance with manufacturer's detail. Do not flash to lead.

Expansion joints shall be installed according to manufacturer's detail.

Roof drains shall be installed in accordance with manufacturer's detail.

** NOTE TO SPECIFIER ** Delete if fleece backed membrane not required.

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 reroofing not required.

In reroofing, old drains shall 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 shall be secured in a manner approved by Dow and/or in accordance with SMACNA guidelines to prevent damage from buckling, or wind exposure. All metal work that is part of the waterproofing envelope shall be sealed, structurally sound, and appropriately anchored to prevent leakage.

Metal Work Installation:

Metal work shall be installed in a manner that prevents damage from buckling or wind.

Metal work shall be sealed and waterproofed.

3.6

INSTALLATION OF OVERBURDEN

** NOTE TO SPECIFIER ** The following description represents a typical garden roof system construction. Variations in the design, components or application should be reviewed with the Dow Technical Review Dept. at (877) 788-8324 to ensure suitability.

General: Prior to installing any overburden over the membrane.

Roofing and flashing work shall be complete.

The system shall have been inspected by roofing manufacturer and approved for application of overburden.

Water test and quality control procedures shall be completed successfully.

The surface of the waterproofing membrane shall be free of dirt and debris of any kind in preparation for the application of overburden layers.

** NOTE TO SPECIFIER ** Minimum compressive strength is 40 psi (275 kPa) for Intensive GardenTop System. Delete if not required.

Dow Extruded Polystyrene (XPS):

Boards shall be installed with staggered end joints should be butted as closely as possible with no gaps over 1/4 inch (6 mm).

When handling insulation avoid damaging or rupturing the facer and/or surface. Damaged areas shall be cut out and replaced with structurally sound insulation, and properly secured in place.

Dow Garden Roof Drain Panels:

Horizontal Surfaces: Drainage panel may be loosely laid directly over the waterproofing membrane and the edges of the core with the flange should be at the higher edge (away from the drains). Panels shall be secured if high winds are expected prior to the placement of overburden system. Minimize direct traffic on surface of the panels until wearing surface is in place. If drainage panel is damaged, check membrane beneath panel and repair both membrane and drainage panel before proceeding.

Vertical Surfaces: Drainage panel may be installed starting at the top or bottom of the wall. The roll may be installed either vertically (perpendicular to the wall) or horizontally (parallel to the wall). When installed vertically, the core flange should be at the upstream edge. This flange position minimizes seepage of water behind the panels. When installed horizontally, the edge of the core with the flange should be at the top.

Corners: Bend panel to make inside corners. For outside corners, cut drain core flush with corners leaving 3 inches (76 mm) of extra fabric. Wrap fabric around exposed edge of drain core, securing with tape to back side of core.

** NOTE TO SPECIFIER ** Intensive GardenTop System only. Delete if not required.

Dow Garden Roof Drain 650 Panels:

Horizontal Surfaces: Drainage panel is loosely laid (fabric side up) directly over the (XPS) insulation layer(s) with the edges of the core with the flange at the higher edge (away from the drains). Panels shall be secured if high winds are expected prior to the placement of overburden system. Minimize direct traffic on surface of the panels until wearing surface is in place. If drainage panel is damaged, check membrane beneath panel and repair both membrane and drainage panel before proceeding.

Landscape Items: Install growth medium, plantings and additional hardscape items in strict accordance with the Contract Documents. Placement of overburden should proceed carefully to not damage previously installed layers.

** NOTE TO SPECIFIER ** Delete if not required.

Roof Walkways Installation: Shall be incorporated into the overburden system and are typically made from a series of high density paver units or similar materials. An approved protection layer shall be installed between the paver system and the roof cover membrane.

3.7

INSPECTION

** NOTE TO SPECIFIER ** For projects requiring labor and material warranty, include substrate acceptance, water test and inspection requirements. Delete if not required. Lead time for inspections: A two-week lead time is typically required for scheduling in-progress or final inspections. Large intensive system projects should have in-progress inspections performed so that the overburden can be installed in stages to secure the membrane.

Substrate Acceptance: Arrange with manufacturer to have the field representative at site to inspect and accept substrate surface before installation of waterproofing materials.

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.

A properly welded seam will have membrane delamination from scrim prior to weld failure.

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.

Inspection: Upon completion of the membrane installation and before the installation of the overburden system, an inspection will be performed by a representative of Dow to ascertain that the roofing system has been installed according to Dow approved specifications and details. The applicator shall provide temporary ballast and protection as necessary but maintain all seams uncovered until an inspection by Dow confirms the project is ready for installation of the overburden system. Upon approval of the project, a Warranty shall be written.

At the discretion of manufacturer, excessive patching as a result of damage to the membrane may require total recover in those areas.

Water Test: Water test completed waterproofing system for a minimum of 24 hours. Owner's representative and manufacturer's representative shall witness water testing and accept water test results before ballast placement is completed.

Manufacturer's authorized applicator shall be responsible for monitoring the application of overburden and backfilling operations to prevent damage to the completed waterproofing system.

Changes: In the event there are deviations or changes from the warranty provisions without written approval of manufacturer, the project will not be eligible for warranty until approved by the manufacturer.

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 manufacturer's approved specifications and details. Upon approval of the project, a Warranty shall be written.

3.8

PROTECTION

Protect installed products until completion of project.

Touch-up, repair or replace damaged products before Substantial Completion.

END OF SECTION