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Home My WebLink AboutLA209450 - APPROVED - Agrimson Engineering Letter Flat___________________________________________________________________________________________ Domus Structural Engineering, LLC P.O. Box 6986 Broomfield, CO 80021 530-864-7055 Domusstructural@gmail.com To: BlueRavenSolar 1403NorthResearchWay,BuildingJ Orem,UT.84097 Subject: CertificationLetter AgrimsonResidence 17888EclipseAve Lakeville,MN.55044 ToWhomItMayConcern, DesignCriteria: භ ApplicableCodes=2018IBC/IRC,ASCE7Ͳ16 භ RoofDeadLoad=7psf(MP1) භ RoofLiveLoad=20psf භ WindSpeed=115mph(Vult),ExposureC භ භ Sincerely, JohnCalvert,P.E. ProjectEngineer Thescopeofthisreportisstrictlylimitedtoanevaluationofthefastenerattachment,underlyingframingandsupporting structureonly.Theattachment'stotheexistingstructurearerequiredtobeinastaggeredpatterntoensureproper distributionofloading.Allpanels,rackingandhardwareshallbeinstalledpermanufacturerspecificationsandwithinspecified designlimitations.Allwaterproofingshallbeprovidedbythemanufacturer.DomusStructuralEngineeringassumesno responsibilityformisuseorimproperinstallationofthesolarPVpanelsorracking. Pleasecontactmewithanyfurtherquestionsorconcernsregardingthisproject. Note:SeismiccheckisnotrequiredsinceSs<.4gandSeismicDesignCategory(SDC)<B Attachment:1Ͳ5/16dia.lagscrewwith2.5inchmin.embedment depth,atspacingshownabove. I hereby certify that this plan, specification or report was prepared by me or under my direct supervision and that I am a duly Licensed Professional Engineer under the laws of the State of Minnesota.John A. Calvert, License No. 52823 Expiration Date: 30-June-2024 January20,2023 Theroofstructureof(MP1)consistsofcompositionshingleonroofplywoodthatissupportedbypreͲmanufacturedtrusses thatarespacedat@24"o.c..Thetopchords,slopedat26degrees,are2x4sections,thebottomchordsare2x4sectionsand thewebmembersare2x4sections.Thetrussmembersareconnectedbysteelgussetplates.Themaxunsupportedprojected horizontaltopchordspanisapproximately6'Ͳ9''. Theexistingroofframingsystemof(MP1)isjudgedtobeadequatetowithstandtheloadingimposedbytheinstallationofthe solarpanels.Noreinforcementisnecessary. GroundSnowLoad=50psfͲRoofSnowLoad=35psf Thespacingofthesolarstandoffsshouldbekeptat48"o.c.forlandscapeand24"o.c.forportraitorientation,witha staggeredpatterntoensureproperdistributionofloads. AjobsiteobservationoftheconditionoftheexistingframingsystemwasperformedbyanauditteamofBlueRavenSolarasa requestfromDomusStructuralEngineering.Allreviewisbasedontheseobservationsandthedesigncriterialistedbelowand onlydeemedvalidifprovidedinformationistrueandaccurate. Ontheabovereferencedproject,theroofstructuralframinghasbeenreviewedforadditionalloadingduetotheinstallation ofthesolarPVadditiontotheroof.Thestructuralreviewonlyappliestothesectionoftheroofthatisdirectlysupportingthe solarPVsystemanditssupportingelements.Theobservedroofframingisdescribedbelow.Iffieldconditionsdiffer, contractortonotifyengineerpriortostartingconstruction. Agrimson Lakeville MN.xlsm 1 Digitally signed by John A. Calvert Date: 2023.01.23 09:46:30 -07'00' Concept Approval ONLYSubject to Field Inspection Inspector Date 2020 MN Bldg Code 01/23/2023dpfannenstein Please provide a copy of the City Approved plans on site at final inspection. ____________________________________________________________________________________ Domus Structural Engineering, LLC P.O. Box 6986 Broomfield, CO 80021 530-864-7055 Domusstructural@gmail.com 50.0 psf (ASCE7 - Eq 7-1) 1 (ASCE7 - Table 7-2) 1 (ASCE7 - Table 7-3) 1 35.0 psf (ASCE7 - Eq 7-2) 1 35.0 psf 3.34 psf 3.0 psf 2.00 ft 6.08 ft 12.17 sft 37 lb 4.00 2.00 0.73 0.00 (Ceiling Not Vaulted) 0.27 7.0 psf 7.8 psf PV Dead Load = 3 psf (Per Blue Raven Solar) DL Adjusted to 26 Degree Slope Point Loads of Standoffs Miscellaneous Vaulted Ceiling Total Roof DL (MP1) Roof Live Load = 20 psf Roof Plywood Roof Dead Load (MP1) Composition Shingle Note: Roof live load is removed in area's covered by PV array. Roof Snow Load Calculations pg = Ground Snow Load = Ce = Exposure Factor = pf = 0.7 Ce Ct I pg Ct = Thermal Factor = I = Importance Factor = Cs = Slope Factor = Standoff Tributary Area = ps = Cspf ps = Sloped Roof Snow Load = pf = Flat Roof Snow Load = DL Adjusted to 26 Degree Slope Gravity Loading PV System Weight Weight of PV System (Per Blue Raven Solar) X Standoff Spacing = Y Standoff Spacing = Note: PV standoffs are staggered to ensure proper distribution of loading 2x4 Top Chords @ 24"o.c. Agrimson Lakeville MN.xlsm 2 ___________________________________________________________________________________________________________ Domus Structural Engineering, LLC P.O. Box 6986 Broomfield, CO 80021 530-864-7055 Domusstructural@gmail.com 115 mph C Gable Roof 26 degrees 20 ft 21.3 ft 0 ft (Eq. 26.10-1) 0.90 (Table 30.3-1) 1.00 (Fig. 26.8-1) 0.85 (Table 26.6-1) 1.00 115 mph (Fig. 26.5-1A) II (Table 1.5-1) qh = 25.95 Zone 1 Zone 2 Zone 3 Positive ya =0.77 0.80 0.80 0.77 GCp =-1.50 -2.50 -3.59 0.52 (Fig. 30.3) Uplift Pressure =-30.0 psf -51.9 psf -74.5 psf 10.3 psf (Eq. 29.4-7) ASD Uplift Pressure =-18.0 psf -31.1 psf -44.7 psf 9.6 psf X Standoff Spacing = 2.00 2.00 1.33 Y Standoff Spacing = 6.08 3.04166667 3.04166667 Tributary Area = 12.17 6.08 4.06 Dead Load on attachment = 37 lb 18 lb 12 lb Footing Uplift (0.6D+0.6W) = -197 lb -179 lb -174 lb Zone 1 Zone 2 Zone 3 Positive ya =0.75 0.80 0.80 0.75 GCp =-1.50 -2.50 -3.49 0.50 (Fig. 30.3) Uplift Pressure =-29.2 psf -51.9 psf -72.5 psf 9.8 psf (Eq. 29.4-7) ASD Uplift Pressure (0.6W)=-17.5 psf -31.1 psf -43.5 psf 9.6 psf X Standoff Spacing = 4.00 4.00 2.67 Y Standoff Spacing = 3.50 1.75 1.75 Tributary Area = 14.00 7.00 4.67 Dead Load on attachment = 42.00 21.00 14.00 Footing Uplift (0.6D+0.6W) = -220 lb -205 lb -195 lb -220 lb 450 lb Therefore, OK Fastener =1 - 5/16" dia. lag Number of Fasteners = 1 Embedment Depth = 2.5 Pullout Capacity Per Inch = 250 lb Fastener Capacity = 625 lb w/ F.S. of 1.5 & DOL of 1.6= 667 lb Therefore, OK Wind Calculations Maximum Design Uplift = Design Wind Pressure Calculations qh = 0.00256 * Kz * Kzt * Kd * Ke * V^2 Kz (Exposure Coefficient) = Kzt (topographic factor) = Wind Speed Exposure Category Roof Shape Roof Slope Effective Wind Area PerASCE7Ͳ16ComponentsandCladding Input Variables Fastener Capacity Check Mean Roof Height Ground Elevation Kd (Wind Directionality Factor) = 667.2 lb capacity > 220 lb demand Ke (Ground Elevation Factor) = V (Design Wind Speed) = Risk Category = Standoff Uplift Calculations-Portrait Standoff Uplift Calculations-Landscape Standoff Uplift Check Standoff Uplift Capacity = 450 lb capacity > 220 lb demand Agrimson Lakeville MN.xlsm 3 ___________________________________________________________________________________________ Domus Structural Engineering, LLC P.O. Box 6986 Broomfield, CO 80021 530-864-7055 Domusstructural@gmail.com (MP1)PASS Dead Load 7.8 psf PV Load 3.3 psf Snow Load 35.0 psf Governing Load Combo = DL + SL Total Load 46.1 psf Fb (psi) = f'b x Cd x Cf x Cr (NDS Table 4.3.1) 1650 x 1.15 x 1 x 1.15 Allowed Bending Stress = 2182.1 psi (wL^2) / 8 = 525.4042 ft# = 6304.85 in# Actual Bending Stress = (Maximum Moment) / S = 2058.8 psi L/180 (E = 1500000 psi Per NDS) = 0.45 in Deflection Criteria Based on = (w*L^4) / (185*E*I) = = L/364 > L/180 Therefore OK Allowed Deflection (Live Load) =L/240 0.337 in (w*L^4) / (185*E*I) L/480 > L/240 Therefore OK Member Area = Fv (psi) = 135 psi (NDS Table 4A) Allowed Shear = Fv * A = Max Shear (V) = w * L / 2 = 311 lb Check Bending Stress (True Dimensions) Continuous Span 0.223 in 0.169 in Member Properties Member Size 2x4 S (in^3) 3.06 1650Fb/1.5E Member Spacing @ 24"o.c. Maximum Moment = Check Deflection I (in^4) 5.36 Lumber Sp/Gr Actual Deflection (Live Load) = Allowed Deflection (Total Load) = Actual Deflection (Total Load) = Allowed > Actual -- 94.4% Stressed -- Therefore, OK 709 lb Allowed > Actual -- 44% Stressed -- Therefore, OK 5.3 in^2 Check Shear w = 92 plf 2x4 Top Chords @ 24"o.c. Member Span = 6' - 9" Framing Check Agrimson Lakeville MN.xlsm 4 Domus Structural Engineering, LLC P.O. Box 6986 Broomfield, CO 80021 530-864-7055 Domusstructural@gmail.com Appendix A: General Notes GENERAL Ɣ The contractor shall verify all dimensions, property setbacks, AHJ/HOA CC&R's, elevations and site conditions before starting work and shall notify Domus Structural Engineering of any discrepancies. Ɣ All report conclusions represent Domus Structural Engineering's best professional judgment based upon industry standards. Ɣ Resolve any conflicts on the drawings with Domus Structural Engineering before proceeding with construction. Ɣ The design criteria used for this project & listed on the first page of the report is based on the engineers best judgement and/or provided by the ATC council. AHJ specific requests may differ. Please contact our team if the design criteria needs to be modified. Ɣ A site visit was not physically conducted by Domus Structural Engineering. The accompanying calculations and certification are provided with the understanding that the site building and construction standards meet an acceptable level of industry standards. It shall be the contractors responsibility to identify any irregularities such as inconsistent framing conditions, water damage, fire damage, cracked, split or noticeably deflecting framing members. Ɣ Domus Structural Engineering is not responsible for enforcing safety measures or regulations. The contractor shall design, construct, and maintain all safety devices including shoring and bracing, and shall be solely responsible for conforming to all local, state and federal safety and health standards, laws and regulations. The contractor shall take necessary precautions to maintain and insure the integrity of the structure during construction. If a lawsuit is filed by one of the contractor's or subcontractor's employees, or any one else, the contractor will indemnify, defend and hold the owner and Domus Structural Engineering harmless of any and all such claims. Ɣ Any and all waterproofing shall be provided by the contractor. Domus Structural Engineering is not responsible for waterproofing. Ɣ All hardware shall be installed per manufacturer specifications and within specified design limitations. Domus Structural Engineering assumes no responsibility for incorrectly installed hardware or hardware installed outside of the manfacturer specifications. USER RELIANCE Ɣ Domus Structural Engineering was engaged by Blue Raven Solar (Client) to perform this assessment. This report and the information therein, are for the exclusive use of the Client. This report has no other purpose and shall not be relied upon, or used, by any other person or entity without the written consent of Dous Structural Engineering. Third parties that obtain this report, or the information within shall have no rights of recourse or recovery against Domus Structural Engineering, it’s officers or employees. ROOF MOUNTED ARRAYS Ɣ If an analysis of a supporting stucture is included in our scope of work, the structural assessment only applies to the section of the roof that is directly supporting the proposed solar PV system. Ɣ No structural members can be cut for conduit, etc., unless specifically shown. Obtain prior written approval for installation of any additional conduit, etc. Ɣ It is assumed that a standard quality of construction care was used to construct the original building. It shall be the contractors responsibility to field verify any and all framing member supporting the proposed PV array are in adequate condition. The contractor shall field inspect for sub-standard construction means, signs of dry rot, mold, fire damage, etc. and notify engineer if any compromised material is found on site prior to starting construction. Ɣ It is assumed that there have been no additional loads (HVAC or MEP equipment, additional layers of roofing, etc) added to the building over the course of the structures histroy. The contractor and/or client shall verify this with the property owner and notify Domus Structural Engineering if additional load has been added to the structure already. Ɣ Flexible utility connections must be used at any building seismic joint. Ɣ Care should be taken to ensure that PV arrays do not preclude drainage of rain water. Ɣ Unless otherwise noted, construction material shall be evenly distributed if placed on framed floors or roofs. Loads shall not exceed the allowable loading for the supporting members and their connections. Ɣ All lags or wood screws at the roof shall be stainless steel and installed withing the middle 1/3 of the dimensional width of the framing members. Ɣ All fasteners shall be a minimum of 6" away from any truss panel or hinge joints, truss plates and/or member ends. Field verify location of fasteners prior to starting construction. All fasteners shall be pre-drilled to avoid splitting existing lumber. Ɣ Domus Structural Engineering is not responsible for downslope effects of snow shedding or sliding off of the PV array nor any damage to downslope decks, roofs, walkways, landscaping, automobiles, pets, people, etc.. If snow guards are requested by the customer, notify Domus Structural Engineering.