ASTM E2766-13(2019)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E2766 − 13 (Reapproved 2019) An American National Standard
Standard Practice for
Installation of Roof Mounted Photovoltaic Arrays on Steep-
Slope Roofs
This standard is issued under the fixed designation E2766; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope service must be judged, nor should this document be applied
without consideration of a project’s many unique aspects. The
1.1 This practice details minimum requirements for the
word “Standard” in the title means only that the document has
installation of roof mounted photovoltaic arrays on steep-
been approved through the ASTM consensus process.
sloped roofs with water-shedding roof coverings. These re-
quirements include proper water-shedding integration with the 1.7 This practice is not intended to replace or supersede any
roof system, material properties, flashing of roof penetrations, other applicable local codes, standards or Licensed Design
and sufficient anchoring per regional design load requirements. Professional instructions for a given installation.
1.1.1 This practice does not apply to building-integrated or
1.8 This standard does not purport to address all of the
adhesively attached photovoltaic systems that are applied as
safety concerns, if any, associated with its use. It is the
roof-covering components.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.2 This practice does not cover the electrical aspects of
mine the applicability of regulatory limitations prior to use.
installation.
Specific hazards are given in Section 8.
1.3 Installation considerations are divided into two distinct
1.9 This international standard was developed in accor-
aspects: the interface between the photovoltaic module and the
dance with internationally recognized principles on standard-
array mounting structure, and the interface between the array
ization established in the Decision on Principles for the
mounting structure and the roof or roof structure.
Development of International Standards, Guides and Recom-
1.4 Safety and hazard considerations unique to this
mendations issued by the World Trade Organization Technical
application, such as worker fall protection, electrical exposure,
Barriers to Trade (TBT) Committee.
accessibility of modules, and roof clearance around the perim-
eter of the array are addressed by other codes, standards, or 2. Referenced Documents
authorities having jurisdiction.
2.1 ASTM Standards:
1.5 This practice is intended to provide recommended D1079 Terminology Relating to Roofing and Waterproofing
installation practices for use by installers, specifiers,
D1761 Test Methods for Mechanical Fasteners in Wood
inspectors, or for specification by photovoltaic module manu- E136 TestMethodforAssessingCombustibilityofMaterials
facturers.
Using a Vertical Tube Furnace at 750°C
E772 Terminology of Solar Energy Conversion
1.6 This practice provides minimum guidelines and should
2.2 AAMA Standards:
be used in conjunction with module and mounting system
AAMA 800 Voluntary Specifications and Test Methods for
manufacturers’ instructions. This practice offers a set of in-
Sealants
structions for performing one or more specific operations. This
2.3 ASCE Standards:
document cannot replace education or experience and should
ASCE 7 Minimum Design Loads for Buildings and Other
be used in conjunction with professional judgment. Not all
Structures
aspects of this practice may be applicable in all circumstances.
ThisASTMStandardisnotintendedtorepresentorreplacethe
standard of care by which the adequacy of a given professional
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
This practice is under the jurisdiction of ASTM Committee E44 on Solar, the ASTM website.
Geothermal and OtherAlternative Energy Sources and is the direct responsibility of Available from American Architectural Manufacturers Association (AAMA),
Subcommittee E44.09 on Photovoltaic Electric Power Conversion. 1827 Walden Office Sq., Suite 550, Schaumburg, IL 60173, http://
Current edition approved April 1, 2019. Published April 2019. Originally www.aamanet.org.
approved in 2013. Last previous edition approved in 2013 as E2766-13. DOI: Available from American Society of Civil Engineers (ASCE), 1801 Alexander
10.1520/E2766-13R19. Bell Dr., Reston, VA 20191, http://www.asce.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2766 − 13 (2019)
2.4 IEC Standards: which can result in water leakage issues if not properly flashed
IEC 61730–1 (2004–10) Photovoltaic (PV) Module Safety or applied to the roof system.
Qualification–Part One: Requirements for Construction
4.2 Structural integrity and durability of the application of
2.5 UL Standards:
theroofmountedarraytotheroofsystemmustbeadequateper
UL 1703 Standard for Flat-Plate Photovoltaic Modules and
applicable codes and regulations. This applies to both the
Panels
photovoltaic module-to-array mounting structure interface and
UL746C PolymericMaterials—UseinElectricalEquipment
the array mounting structure-to-roof interface.
Evaluations
4.3 The installation of roof mounted arrays presents certain
UL 60950–1 Table J.1 Electrotechnical Potentials (V)
hazards that must be addressed, which include fall protection,
2.6 Other Standards:
carrying loads up ladders, wind and rain exposure during
IBC International Building Code
installation, and electrical exposure during connections.
IEC International Electrical Code
4.4 The topics covered in 4.1 through 4.3 are potentially a
IFC International Fire Code
significant barrier to broad acceptance of roof mounted photo-
NFPA 1 Fire Protection Code
voltaic systems if not adequately addressed.
NDS National Design Specification for Wood Construction
5. Material Requirements
3. Terminology
5.1 Design Life Alignment between the Array and the
3.1 Definitions: Definitions of terms used in this standard Roof—In many cases, the design life of the photovoltaic array
may be found in Terminology D1079 and E772.
may be significantly longer than the estimated design or
3.1.1 steep-slope, adj—in roofing, that which commonly
remaining life of the roof covering. The condition of the roof
describes an incline of a roof which is greater than 25 % (14°
structure and surface shall be evaluated to determine whether it
or 3:12 vertical rise to horizontal run). D1079.
is sufficient to meet the design life of the roof mounted array.
Consultation with a roofing professional and building owner is
3.2 Definitions of Terms Specific to This Standard:
recommended.
3.2.1 array mounting structure, n— all structural and me-
chanical materials used to support and anchor the photovoltaic 5.2 Design Life (Exposure and Durability) of Array Mount-
modulesontheroofsystembetweentheattachmentsystemand
ing Structure—Materials used in the array mounting structure
the roof deck. shall be selected such that the expected design life of the array
mounting structure is no less than the design life of the
3.2.2 attachment system, n—all structural and mechanical
photovoltaic modules. Test data from similar exposure appli-
materials used to support and anchor the photovoltaic modules
cations is acceptable.
to the array mounting structure.
5.2.1 Polymeric based materials used in the array mounting
3.2.3 design life, n—the period of time during which a
structure shall maintain structural integrity through expected
systemcomponentisexpectedtoperformitsintendedfunction,
thermal exposure. Any polymeric materials in the structure
without significant degradation of performance and without
shall have a relative thermal index (RTI), as defined in UL
requiring major maintenance or replacement. E772
746C,ofatleast90°C.Thethermalresistanceofanypolymeric
3.2.4 licensed design professional, LDP, n—an individual
material in direct contact with the module shall be specified by
licensed to approve structural designs in the state or jurisdic-
the module manufacturer.
tion where the roof mounted photovoltaic array will be
5.3 Adhesive Sealant Requirements:
installed.
5.3.1 Adhesives Used in Structural Elements—Bond
3.2.5 representative section, n—one or more modules con-
strength must be sufficient to withstand structural loading as
nected to an array mounting structure utilizing the same
determined by 6.1 and be durable through the expected design
connecting devices as would be used in an installation.
life of the array mounting structure. The structural integrity of
the bond joining the components of the mounting structure to
4. Significance and Use
the array (or to each other) shall be verified through system
4.1 Withtherapidgrowthoftheuseofphotovoltaicsystems
testing per the structural requirements detailed in Section 6.
in buildings, roof mounted arrays continue to be one of the 5.3.2 Adhesives Used in Non-Structural Bonding—Sealants
most prevalent forms of installations. These roof mounted
(such as for glazings or other components) must be verified to
arrays typically feature penetrations into the roof system, meet the criteria for exterior perimeter sealants set forth in
Section 808.3 of AAMA 800.
5.4 Corrosion of Resistance of Metals:
Available from International Electrotechnical Commission (IEC), 3, rue de
5.4.1 Dissimilar metals in direct contact may corrode. Use
Varembé, P.O. Box 131, CH-1211 Geneva 20, Switzerland, http://www.iec.ch.
6 appropriate precautions per UL 60950-1 Table J.1 Electro-
Available from Underwriters Laboratories (UL), 2600 N.W. Lake Rd., Camas,
chemical Potentials (V).
WA 98607-8542, http://ww
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