【国外标准】 Standard Practice for Installation of Roof Mounted Photovoltaic Arrays on Steep-Slope Roofs

4.1 With the rapid growth of the use of photovoltaic systems in buildings, roof mounted arrays continue to be one of the most prevalent forms of installations. These roof mounted arrays typically feature penetrations into the roof system, which can result in water leakage issues if not properly flashed or applied to the roof system.4.2 Structural integrity and durability of the application of the roof mounted array to the roof system must be adequate per applicable codes and regulations. This applies to both the photovoltaic module-to-array mounting structure interface and the array mounting structure-to-roof interface.4.3 The installation of roof mounted arrays presents certain hazards that must be addressed, which include fall protection, carrying loads up ladders, wind and rain exposure during installation, and electrical exposure during connections.4.4 The topics covered in 4.1 through 4.3 are potentially a significant barrier to broad acceptance of roof mounted photovoltaic systems if not adequately addressed.1.1 This practice details minimum requirements for the installation of roof mounted photovoltaic arrays on steep-sloped roofs with water-shedding roof coverings. These requirements include proper water-shedding integration with the roof system, material properties, flashing of roof penetrations, and sufficient anchoring per regional design load requirements.1.1.1 This practice does not apply to building-integrated or adhesively attached photovoltaic systems that are applied as roof-covering components.1.2 This practice does not cover the electrical aspects of installation.1.3 Installation considerations are divided into two distinct aspects: the interface between the photovoltaic module and the array mounting structure, and the interface between the array mounting structure and the roof or roof structure.1.4 Safety and hazard considerations unique to this application, such as worker fall protection, electrical exposure, accessibility of modules, and roof clearance around the perimeter of the array are addressed by other codes, standards, or authorities having jurisdiction.1.5 This practice is intended to provide recommended installation practices for use by installers, specifiers, inspectors, or for specification by photovoltaic module manufacturers.1.6 This practice provides minimum guidelines and should be used in conjunction with module and mounting system manufacturers’ instructions. This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This ASTM Standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project’s many unique aspects. The word “Standard” in the title means only that the document has been approved through the ASTM consensus process.1.7 This practice is not intended to replace or supersede any other applicable local codes, standards or Licensed Design Professional instructions for a given installation.1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific hazards are given in Section 8.1.9 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.