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HomeMy WebLinkAboutLA196458 - Approved A7 IronRidge_XR100Flush_Certification_UFO_MN-716© 2020 IronRidge, Inc. MN Flush Mount System Certification Letter - 1 28357 Industrial Blvd. Hayward, CA 94545 1-800-227-9523 IronRidge.com Attn: Corey Geiger, COO, IronRidge Inc. Date: July 24th, 2020 Re: Structural Certification and Span Tables for the IronRidge Flush Mount System This letter addresses the structural performance and code compliance of IronRidge’s Flush Mount System. The contents of the letter shall be read in its entirety before applying to any project design. The Flush Mount System is a proprietary rooftop mounting system used to support photovoltaic (PV) modules installed in portrait or landscape orientation and set parallel to the underlying roof surface. PV modules are supported by extruded aluminum XR Rails and secured to the rails with IronRidge mounting clamps. The XR Rails are side mounted to a selected roof attachment with 3/8” stainless steel bonding hardware and then attached directly to the roof structure or to a stanchion that is fastened to the underlying roof structure. Assembly details of a typical Flush Mount installation and its core components are shown in Exhibit EX-0015. The IronRidge Flush Mount System is designed and certified to the structural requirements of the reference standards listed below, for the load conditions and configurations tabulated in the attached span tables. • ASCE/SEI 7-16 Minimum Design Loads for Buildings and Other Structures (ASCE 7-16) • 2018 International Building Code (IBC-2018) • 2020 Minnesota Building Code • 2020 Minnesota Provisions to the State Building Code • 2015 Aluminum Design Manual (ADM-2015) The tables included in this letter provide the maximum allowable spans of XR Rails in the Flush Mount System for the respective loads and configurations listed, covering wind exposure categories B, C, & D, roof zones provided in ASCE 7-16 for gable & hip roof profiles, and roof slopes of 8° to 45°. The tabulated spans are applicable when the following conditions are met: 1. Span is the distance between two adjacent roof attachment points (measured at the center of the attachment fastener). 2. The underlying roof pitch, measured between the roof surface and horizontal plane, is 45° or less. 3. The mean roof height, defined as the average of the roof eave height and the roof ridge height measured from grade, does not exceed 30 feet. 4. A clearance from the underside of the array to the roof surface of 2” minimum shall be provided and the height of the array, the distance from the module top surface to the roof surface (defined as h2), shall not exceed 10”. 5. Module length and area shall not exceed the maximum values listed on the respective span tables. 6. All Flush Mount components shall be installed in a professional workmanlike manner per IronRidge’s Flush Mount Installation Manual and other applicable standards for the general roof construction practice. © 2020 IronRidge, Inc. MN Flush Mount System Certification Letter - 2 28357 Industrial Blvd. Hayward, CA 94545 1-800-227-9523 IronRidge.com The parameters and adjustments allowed in the span tables are defined as the following: 1. The Flush Mount System is designed as a Risk Category II structure as defined by ASCE 7-16 Table 1.5-1. 2. Wind speed shall conform to ASCE 7-16 Fig. 26.5-1B (for Risk Category II) and applicable state & local county/city amendments to the IBC. No special wind topographic features are included and both topographic coefficient (Kzt) and wind ground elevation factor (Ke) are taken as 1.0. 3. Snow load used in the span tables is the ground snow and shall conform to ASCE 7-16 Fig. 7.2-1 and applicable state & local county/city amendments to the IBC. If the local jurisdiction specified snow load is in the format of a flat roof snow, it shall first be converted to a ground snow following the local building code/ amendments before the application of the attached span tables. No special snow conditions are considered including unbalanced, drifting, sliding, retention, or ponding snow. No rain-on-snow surcharge load is considered. The span tables do not apply to buildings which are intentionally kept below freezing, kept just above freezing, or unheated. 4. The span tables reflect the ASCE 7 prescribed earthquake loads with the maximum magnitudes being: (a) For ground snow no greater than 42psf: Ss ” 2.0g for Site Class A, B, C, & D. (b) For ground snow greater than 65psf: Ss ” 1.0g for Site Class A, B, C, & D. (c) For ground snow between 42 and 65psf: Ss ” 1.5g for Site Class A, B, C, & D. 5. Roof zones are defined by ASCE 7-16 Figure 30.3-2A to Figure 30.3-2I and are organized into three groups in which the zones share the same External Pressure Coefficients (GCp). Roof zones comprising each group along with each roof zone’s size and location are depicted in Figures 2 and 3 below each span table. 6. The maximum rail cantilever length, measured from the rail end to the nearest attachment point, shall be the lesser of the following two conditions: 40% of the allowable span provided for the respective load & configuration condition from the span tables, or 36”. 7. Allowable span length in the charts may be multiplied by a factor of 1.08 if the rails are continuous over a minimum of three spans. 8. No rail splices are allowed in the cantilever, outer 2/3 of end spans, or middle 1/3 of interior spans. 9. Shaded cells of the span tables indicate conditions in which UFO Mid Clamp connection capacity is exceeded. If such conditions are encountered contact support@ironridge.com. 10. Systems using CAMO module clamps shall be installed with the following guidance: a) For single module installations (orphan modules) using modules with a length greater than 67.5”, CAMO clamps shall not be installed in regions that experience ground snow loads of 70psf and greater. Such scenarios are shown by asterisks in the applicable span tables. b) CAMO will function within a module’s design load ratings. Be sure the specific module being used with CAMO meets the dimensional requirements shown in the figure below and that the module selected is suitable for the environmental conditions of a particular project. Figure 1: CAMO Module Frame Dimensional Requirements © 2020 IronRidge, Inc. MN Flush Mount System Certification Letter - 3 28357 Industrial Blvd. Hayward, CA 94545 1-800-227-9523 IronRidge.com Span values for Exposed and Edge module conditions, as defined below, are included in the attached span tables and shall be used when each condition exists. The maximum allowable span for Exposed or Edge modules shall be the lesser of the following two: (1) The span value for the Exposed or Edge module condition; (2) The span value determined by site wind speed and ground snow load. Additionally, irrespective of the lesser span, the shaded cells for the Exposed and Edge module conditions which reflect the UFO clamp usage limitation detailed in note 9 of page 2 shall apply to the respective condition. 1. Exposed Module conditions: A module is defined as Exposed (per Section 29.4.4 of ASCE 7-16) if the distance from any of its free edges (an edge with no connectivity to other modules) to its facing roof edge (such as eave, ridge, rake, or hip) is greater than 0.5h (h is ASCE defined building height) AND if the distance from its free edge to any other adjacent array or panel is greater than 4 feet. The allowable spans and cantilever shall only be applied to the portion of rail directly under Exposed Modules. 2. Edge Module conditions: A module is defined as an Edge Module when its distance from any side of the module to its facing perimeter roof edge (such as eave, ridge, rake, or hip) is less than 2 times the height of the array (2h2) where h2 is measured from the roof surface to the top surface of the module. The allowable spans and cantilever shall only be applied to the portion of rail directly under Edge Modules. Additionally, if the roof edge is the eave or ridge, only the rail nearest to that roof edge shall be considered for this span adjustment. © 2020 IronRidge, Inc. MN Flush Mount System Certification Letter - 4 28357 Industrial Blvd. Hayward, CA 94545 1-800-227-9523 IronRidge.com The span tables provided in this letter are certified based on the structural performance of IronRidge XR Rails only with no consideration of the structural adequacy of the chosen roof attachments, PV modules, or the underlying roof supporting members. It is the responsibility of the installer or system designer to verify the structural capacity and adequacy of the aforementioned system components in regards to the applied or resultant loads of any chosen array configuration. Sincerely, Gang Xuan, PE Senior Structural Engineer Date Sealed: Date: 2020.07.29 13:18:05 -07'00'