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HomeMy WebLinkAboutLA207574 - APPROVED - Huray 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 HurayResidence 16534DoddLn Lakeville,MN.55044 ToWhomItMayConcern, DesignCriteria: භ ApplicableCodes=2018IBC/IRC,ASCE7Ͳ16 භ RoofDeadLoad=7psf(MP1,2,3&4) 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. October18,2022 Theroofstructuresof(MP1,2,3&4)consistofcompositionshingleonroofplywoodthatissupportedbypreͲmanufactured trussesthatarespacedat@24"o.c..Thetopchords,slopedat34degrees,are2x4sections,thebottomchordsare2x4 sectionsandthewebmembersare2x4sections.Thetrussmembersareconnectedbysteelgussetplates.Themax unsupportedprojectedhorizontaltopchordspanisapproximately6'Ͳ3''. Theexistingroofframingsystemsof(MP1,2,3&4)arejudgedtobeadequatetowithstandtheloadingimposedbythe installationofthesolarpanels.Noreinforcementisnecessary.Whereitisrequiredforstandoffs,installvertical2x6blocking betweentrusstopchords.AttachblocktoadjacenttrusseswithSimpsonA34clipsateachend.Seeattacheddetailforfurther specifications. GroundSnowLoad=50psfͲRoofSnowLoad=35psf Thespacingofthesolarstandoffsshouldbekeptat48"o.c.forlandscapeand24"o.c.forportraitorientation,withastaggered patterntoensureproperdistributionofloads. AjobsiteobservationoftheconditionoftheexistingframingsystemwasperformedbyanauditteamofBlueRavenSolarasa requestfromDomusStructuralEngineering.Allreviewisbasedontheseobservationsandthedesigncriterialistedbelowand onlydeemedvalidifprovidedinformationistrueandaccurate. Ontheabovereferencedproject,theroofstructuralframinghasbeenreviewedforadditionalloadingduetotheinstallationof thesolarPVadditiontotheroof.Thestructuralreviewonlyappliestothesectionoftheroofthatisdirectlysupportingthesola PVsystemanditssupportingelements.Theobservedroofframingisdescribedbelow.Iffieldconditionsdiffer,contractorto notifyengineerpriortostartingconstruction. Huray Lakeville MN.xlsm 1 I hereby certify that this plan, specification or report wasprepared by me or under my direct supervision and that I am aduly Licensed Professional Engineer under the laws of the Stateof Minnesota.John A. Calvert, License No. 52823 ExpirationDate: 30-June-2024 Digitally signed by John A. Calvert Date: 2022.10.18 16:25:59 -06'00' Concept Approval ONLYSubject to Field Inspection Inspector Date 2020 MN Bldg Code 10/19/2022dpfannenstein Provide copy of city approved plans on the job site for the inspector I hereby certify that this plan, specification or report wasprepared by me or under my direct supervision and that I am aduly Licensed Professional Engineer under the laws of the Stateof Minnesota.John A. Calvert, License No. 52823 ExpirationDate: 30-June-2024 10/18/202 ____________________________________________________________________________________ Domus Structural Engineering, LLC P.O. Box 6986 Broomfield, CO 80021 530-864-7055 Domusstructural@gmail.com 50 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 3.02 psf 2.5 psf 2.00 ft 6.08 ft 12.17 sft 30 lb 4.00 2.00 0.73 0.00 (Ceiling Not Vaulted) 0.27 7.0 psf 8.4 psf PV Dead Load = 2.5 psf (Per Blue Raven Solar) DL Adjusted to 34 Degree Slope Point Loads of Standoffs Miscellaneous Vaulted Ceiling Total Roof DL (MP1,2,3&4) Roof Live Load = 20 psf Roof Plywood Roof Dead Load (MP1,2,3&4) 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 34 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. Huray 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 34 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 =-1.71 -2.00 -2.89 0.87 (Fig. 30.3) Uplift Pressure =-34.3 psf -41.5 psf -60.0 psf 17.3 psf (Eq. 29.4-7) ASD Uplift Pressure =-20.6 psf -24.9 psf -36.0 psf 10.4 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 = 30 lb 15 lb 10 lb Footing Uplift (0.6D+0.6W) = -232 lb -142 lb -140 lb Zone 1 Zone 2 Zone 3 Positive ya =0.75 0.80 0.80 0.75 GCp =-1.65 -2.00 -2.83 0.84 (Fig. 30.3) Uplift Pressure =-32.2 psf -41.5 psf -58.7 psf 16.4 psf (Eq. 29.4-7) ASD Uplift Pressure (0.6W)=-19.3 psf -24.9 psf -35.2 psf 9.8 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 = 35.00 17.50 11.67 Footing Uplift (0.6D+0.6W) = -250 lb -164 lb -157 lb -250 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 > 250 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 > 250 lb demand Huray Lakeville MN.xlsm 3 ___________________________________________________________________________________________ Domus Structural Engineering, LLC P.O. Box 6986 Broomfield, CO 80021 530-864-7055 Domusstructural@gmail.com (MP1,2,3&4)PASS Dead Load 8.4 psf PV Load 3.0 psf Snow Load 35.0 psf Governing Load Combo = DL + SL Total Load 46.5 psf Fb (psi) = f'b x Cd x Cf x Cr (NDS Table 4.3.1) 900 x 1.15 x 1.5 x 1.15 Allowed Bending Stress = 1785.3 psi (wL^2) / 8 = 453.7019 ft# = 5444.422 in# Actual Bending Stress = (Maximum Moment) / S = 1777.8 psi L/180 (E = 1600000 psi Per NDS) = 0.416 in Deflection Criteria Based on = (w*L^4) / (185*E*I) = = L/484 > L/180 Therefore OK Allowed Deflection (Live Load) =L/240 0.312 in (w*L^4) / (185*E*I) L/642 > L/240 Therefore OK Member Area = Fv (psi) = 180 psi (NDS Table 4A) Allowed Shear = Fv * A = Max Shear (V) = w * L / 2 = 290 lb Check Bending Stress (True Dimensions) Continuous Span 0.155 in 0.117 in Member Properties Member Size 2x4 S (in^3) 3.06 DF#2 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 -- 99.6% Stressed -- Therefore, OK 945 lb Allowed > Actual -- 30.8% Stressed -- Therefore, OK 5.3 in^2 Check Shear w = 93 plf 2x4 Top Chords @ 24"o.c. Member Span = 6' - 3" Framing Check Huray Lakeville MN.xlsm 4