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HomeMy WebLinkAboutHouse Engineering Letter___________________________________________________________________________________________ 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 HouseResidence 11095HuntingtonCt Carmel,IN.46033 ToWhomItMayConcern, DesignCriteria: භ ApplicableCodes=2014IndianaStateBuildingCode,ASCE7Ͳ10 භ RoofDeadLoad=12psf(MP1) භ RoofLiveLoad=20psf භ WindSpeed=115mph(Vult),ExposureC,RiskCategoryII භ භ Sincerely, JohnCalvert,P.E. ProjectEngineer June16,2021 Theroofstructureof(MP1)consistsofcompositionshingleonroofplywoodthatissupportedby2x6rafters@16"o.c..The rafterssupportavaultedceilingandhaveamaxprojectedhorizontalspanof12'Ͳ6",withaslopeof40degrees.Theraftersare supportedattheridgebyaridgeboardandattheeavebyaloadbearingwall. Theexistingroofframingsystemof(MP1)isjudgedtobeadequatetowithstandtheloadingimposedbytheinstallationofthe solarpanels.Noreinforcementisnecessary. GroundSnowLoad=20psfͲRoofSnowLoad=14psf Thespacingofthesolarstandoffsshouldbekeptat64"o.c.forlandscapeand48"o.c.forportraitorientation,withastaggered patterntoensureproperdistributionofloads. AjobsiteobservationoftheconditionoftheexistingframingsystemwasperformedbyanauditteamofBlueRavenSolarasa requestfromDomusStructuralEngineering.Allreviewisbasedontheseobservationsandthedesigncriterialistedbelowand onlydeemedvalidifprovidedinformationistrueandaccurate. Ontheabovereferencedproject,theroofstructuralframinghasbeenreviewedforadditionalloadingduetotheinstallationof thesolarPVadditiontotheroof.Thestructuralreviewonlyappliestothesectionoftheroofthatisdirectlysupportingthesolar PVsystemanditssupportingelements.Theobservedroofframingisdescribedbelow.Iffieldconditionsdiffer,contractorto notifyengineerpriortostartingconstruction. Thescopeofthisreportisstrictlylimitedtoanevaluationofthefastenerattachment,underlyingframingandsupporting structureonly.Theattachment'stotheexistingstructurearerequiredtobeinastaggeredpatterntoensureproperdistribution ofloading.Allpanels,rackingandhardwareshallbeinstalledpermanufacturerspecificationsandwithinspecifieddesign limitations.Allwaterproofingshallbeprovidedbythemanufacturer.DomusStructuralEngineeringassumesnoresponsibility formisuseorimproperinstallationofthesolarPVpanelsorracking. Pleasecontactmewithanyfurtherquestionsorconcernsregardingthisproject. Note:SeismiccheckisnotrequiredsinceSs<.4gandSeismicDesignCategory(SDC)<B Attachment:1Ͳ5/16dia.lagscrewwith2.5inchmin.embedment depth,atspacingshownabove. House Carmel IN.xlsm 1 Digitally signed by John A. Calvert Date: 2021.06.16 15:29:36 -06'00' ____________________________________________________________________________________ Domus Structural Engineering, LLC P.O. Box 6986 Broomfield, CO 80021 530-864-7055 Domusstructural@gmail.com 20 psf (ASCE7 - Eq 7-1) 1 (ASCE7 - Table 7-2) 1 (ASCE7 - Table 7-3) 1 14.0 psf (ASCE7 - Eq 7-2) 1 14.0 psf 3.92 psf 3.0 psf 4.00 ft 5.50 ft 22.00 sft 66 lb 4.00 2.00 1.72 4.00 0.28 12.0 psf 15.7 psf 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 2x6 Rafters @ 16"o.c. I = Importance Factor = Cs = Slope Factor = Standoff Tributary Area = ps = Cspf ps = Sloped Roof Snow Load = pf = Flat Roof Snow Load = DL Adjusted to 40 Degree Slope Roof Snow Load Calculations pg = Ground Snow Load = Ce = Exposure Factor = pf = 0.7 Ce Ct I pg Ct = Thermal Factor = 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. DL Adjusted to 40 Degree Slope Point Loads of Standoffs Miscellaneous Vaulted Ceiling Total Roof DL (MP1) PV Dead Load = 3 psf (Per Blue Raven Solar) House Carmel IN.xlsm 2 ___________________________________________________________________________________________ Domus Structural Engineering, LLC P.O. Box 6986 Broomfield, CO 80021 530-864-7055 Domusstructural@gmail.com 115 mph C Hip/Gable 40 degrees 20 ft 19.3 ft (Eq. 30.3-1) 0.9 (Table 30.3-1) 1 (Fig. 26.8-1) 0.85 (Table 26.6-1) 115 mph (Fig. 26.5-1A) II (Table 1.5-1) qh = 25.90 15.54 Zone 1 Zone 2 Zone 3 Positive GCp = -0.94 -1.15 -1.15 0.84 (Fig. 30.4-1) Uplift Pressure = -14.67 psf -17.91 psf -17.91 psf 21.7 psf X Standoff Spacing = 4.00 4.00 2.67 Y Standoff Spacing = 5.50 2.75 2.75 Tributary Area = 22.00 11.00 7.33 Dead Load on Attachment= 66.00 33.00 22.00 Footing Uplift (0.6D+0.6W)= -283 lb -177 lb -118 lb Zone 1 Zone 2 Zone 3 Positive GCp = -0.94 -1.15 -1.15 0.84 (Fig. 30.4-1) Uplift Pressure = -14.67 psf -17.91 psf -17.91 psf 10.0 psf (Minimum) X Standoff Spacing = 5.33 5.33 3.56 Y Standoff Spacing = 3.50 1.75 1.75 Tributary Area = 18.67 9.33 6.22 Dead Load on Attachment= 56.00 28.00 18.67 Footing Uplift (0.6D+0.6W) = -240 lb -150 lb -100 lb -283 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 = Standoff Uplift Capacity = 450 lb capacity > 283 lb demand Fastener Capacity Check Standoff Uplift Check Kz (Exposure Coefficient) = Kzt (topographic factor) = Kd (Wind Directionality Factor) = V (Design Wind Speed) = Risk Category = qh = 0.00256 * Kz * Kzt * Kd * V^2 Wind Pressure P = qh*G*Cn Exposure Category PerASCE7Ͳ10ComponentsandCladding Mean Roof Height Roof Slope 667.2 lb capacity > 283 lb demand 0.6 * qh = Standoff Uplift Calculations-Landscape Input Variables Wind Speed Effective Wind Area Design Wind Pressure Calculations Roof Shape Standoff Uplift Calculations-Portrait House Carmel IN.xlsm 3 ___________________________________________________________________________________________ Domus Structural Engineering, LLC P.O. Box 6986 Broomfield, CO 80021 530-864-7055 Domusstructural@gmail.com (MP1)PASS Dead Load 15.7 psf PV Load 3.9 psf Snow Load 14.0 psf Governing Load Combo = DL + SL Total Load 33.6 psf Fb (psi) = f'b x Cd x Cf x Cr (NDS Table 4.3.1) 900 x 1.15 x 1.3 x 1.15 Allowed Bending Stress = 1547.3 psi (wL^2) / 8 = 874.5081 ft# = 10494.1 in# Actual Bending Stress = (Maximum Moment) / S = 1387.7 psi L/180 (E = 1600000 psi Per NDS) = 0.833 in Deflection Criteria Based on = (5*w*L^4) / (384*E*I) = = L/203 > L/180 Therefore OK Allowed Deflection (Live Load) =L/240 0.625 in (5*w*L^4) / (384*E*I) L/486 > L/240 Therefore OK Member Area = Fv (psi) = 180 psi (NDS Table 4A) Allowed Shear = Fv * A = Max Shear (V) = w * L / 2 = 280 lb Framing Check 8.3 in^2 Check Shear w = 45 plf 2x6 Rafters @ 16"o.c. Member Span = 12' - 6" 1485 lb Allowed > Actual -- 18.9% Stressed -- Therefore, OK DF#2 Member Spacing @ 16"o.c. Maximum Moment = Check Deflection I (in^4) 20.80 Lumber Sp/Gr Actual Deflection (Live Load) = Allowed Deflection (Total Load) = Actual Deflection (Total Load) = Allowed > Actual -- 89.7% Stressed -- Therefore, OK Member Properties Member Size 2x6 S (in^3) 7.56 0.309 in Simple Span 0.740 in Check Bending Stress (True Dimensions) House Carmel IN.xlsm 4