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Home My WebLink AboutWilley Fridley MN Stamped Engineering Letter (2) Domus Domus Structural Engineering, LLC S- T R U C; T t t RA 1, P.O. Box 560 Broomfield, CO 80038 M- N G T N E E R i N G 1. 1. C 530-864-7055 projects@domusstruc.com May 23,2023 To: Blue Raven Solar 1403 North Research Way,Building J Orem,UT.84097 Subject: Certification Letter Willey Residence 7830 Firwood Way NE Fridley,MN.55432 To Whom It May Concern, Ajobsite observation of the condition of the existing framing system was performed by an audit team of Blue Raven Solar as a request from Domus Structural Engineering.All review is based on these observations and the design criteria listed below and only deemed valid if provided information is true and accurate. On the above referenced project,the roof structural framing has been reviewed for additional loading due to the installation of the solar PV addition to the roof.The structural review only applies to the section of the roof that is directly supporting the solar PV system and its supporting elements.The observed roof framing is described below.If field conditions differ,contractor to notify engineer prior to starting construction. The roof structures of(MP1-3)consist of composition shingle on roof plywood that is supported by pre-manufactured trusses that are spaced at @ 24"o.c..The top chords,sloped at 30 degrees,are 2x4 sections,the bottom chords are 2x4 sections and the web members are 2x4 sections.The truss members are connected by steel gusset plates.The max unsupported projected horizontal top chord span is approximately 6'4" The roof structure of(MP4)consists of composition shingle on roof plywood that is supported by nominal 2x4 rafters @ 16"o.c. paired with 2x6 ceilingjoists @ 16"o.c..The rafters have a max projected horizontal span of 10'-3",with a slope of 22 degrees.The rafters are connected at the ridge to a ridge board and are supported at the eave by a load bearing wall. The existing roof framing systems of(MP1-3)are judged to be adequate to withstand the loading imposed by the installation of the solar panels.No reinforcement is necessary. The existing roof framing system of(MP4)is judged to be inadequate to withstand the loading imposed by the installation of the solar panels.Structural reinforcement is required. Sister upgrade is required for(MP4)on all rafters that directly support solar PV that do not have a supporting strut and where the horizontal span exceeds 7'4'.Stitch new 2x4 DF#2(min)to existing member with 1/4 in.x 3 in.wood screws @ 16"o.c.or 10d nails @ 6"o.c..Lap as needed with 4'-0"lap per attached detail. The spacing of the solar standoffs should be kept at 48"o.c.for landscape and 24"o.c.for portrait orientation,with a staggered pattern to ensure proper distribution of loads.For the Flashloc Duos,the spacing of the solar standoffs should be kept at 30"o.c. for landscape and 18"o.c.for portrait orientation,with a staggered pattern to ensure proper distribution of loads. The scope of this report is strictly limited to an evaluation of the fastener attachment,underlying framing and supporting structure only.The attachment's to the existing structure are required to be in a staggered pattern to ensure proper distribution of loading. All panels,racking and hardware shall be installed per manufacturer specifications and within specified design limitations.All waterproofing shall be provided by the manufacturer. Domus Structural Engineering assumes no responsibility for misuse or improper installation of the solar PV panels or racking. Note:Seismic check is not required since Ss<.4g and Seismic Design Category(SDC)<B Design Criteria: PA- CAI •Applicable Codes=2020 Minnesota Building Code,ASCE 7-16 ` ••:` •Roof Dead Load=7 psf(MP1-3) -- 9 psf(MP4) •••" '� a,Roof Live Load=20 psf ICE D •Wind Speed=115 mph(Vult),Exposure C •Ground Snow Load=50 psf- Roof Snow Load=35 psf ENG E •Attachment:1-5/16 dia.lag screw with 2.5 inch min.embedment �2�2� - depth,at spacing shown above. •Attachment:6-#12 Wood Screws into wood decking,at spacing ,. NS . shown above. OF M!X4 Digrtalhy,$I' ned by John Please contact me with any further questions or concerns regarding this project. A. Calvert Sincerely, 2 2 hereby certify that this plan,specification or report— by me or Date: 2 0 2 3.0 5.2 3 under my direct supervision and that I am a duly Licensed Professional aws 1 Q V.O 1 :19 -06'00 f Engineer underthe l ofthe State of Minnesota.John A.Calvert,License John Calvert,P.E. No.52823 Expiration Date:30-June-2024 Project Engineer Willey Fridley MN 1 1X DECKING OR SHEATHING (N) INSTALL SIMPSON A34 CLIP. (E) RAFTERS (N) SISTER MEMBER TO BE FULL INSTALL END GROUP OF LENGTH.ATTACH TO(E)RAFTER W/ FASTENERS WITHIN 6"OF J'x3"WOOD SCREWS STAGGERED EACH END.(3)SCREWS MIN TOP AND BOTTOM @ 16"O.C. (E) CEILING JOIST SISTER TO BE WITHIN 3"OF TOP OF CEILING JOIST OR TOP OF WALL OPTION 1 - FULL LENGTH SISTER SEE LETTER FOR UPGRADE LAP LENGTH AND SIZE. 1X DECKING OR SHEATHING (N) INSTALL SIMPSON A34 CLIP. (E) RAFTERS (N) SISTER MEMBER TO BE FULL LENGTH.ATTACH TO(E)RAFTER W/ INSTALL END GROUP OF /,A J'x3"WOOD SCREWS STAGGERED FASTENERS WITHIN 6"OF \ / TOP AND BOTTOM @ 16"O.C. EACH END.(3)SCREWS MIN (E) CEILING JOIST P. CAt \ -•� / SISTER TO BE WITHIN 3"OF � � TOP OF CEILING JOIST OR �' J` TOP OF WALL 10EN D OPTION 2 - OVERLAPPED SISTER SEE LETTER FOR UPGRADE LAP LENGTH AND SIZE. ENC E ` (N) SISTER RAFTER 52823 A� 50: w o,� F'•- . ... - � . (N) SISTER RAFTERL/Z (E) RAFTER 5/23/23 ///I/OF•M,NN\�\ SECTION A-A "fill SISTER UPGRADE OPTIONS ALTERNATIVE FASTENER SCHEDULE:10d NAILS STAGGERED TOP AND BOTTOM AT 6"O.C. 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 PROJECT NAME:SISTER UPGRADE Scale: N.T.S. 1/18/23 Project Number:Solar PV Project Description:SISTER UPGRADE Drawn By:JAC Drawing Name: Revisions: A SISTER B Do m u S Domus Structural Engineering, LLC -c7 TRi) CTURA 1, P.O. Box560 Broomfield, CO 80038 E N G I N E F. R T N G T_ T. (: 530-864-7055 projects@domusstruc.com Gravity Loading Roof Snow Load Calculations pg=Ground Snow Load= 50.0 psf pf=0.7 Ce Cf I pg (ASCE7-Eq 7-1) Ce=Exposure Factor= 1 (ASCE7-Table 7-2) Cf=Thermal Factor= 1 (ASCE7-Table 7-3) 1=Importance Factor= 1 pf=Flat Roof Snow Load= 35.0 psf p5=CSpf (ASCE7-Eq 7-2) Cs=Slope Factor= 1 p,=Sloped Roof Snow Load= 35.0 psf PV Dead Load=3 psf(Per Blue Raven Solar) DL Adjusted to 30 Degree Slope 3.46 psf PV System Weight Weight of PV System(Per Blue Raven Solar) 3.0 psf X Standoff Spacing= 2.00 ft Y Standoff Spacing= 5.65 ft Standoff Tributary Area= 11.31 sft Point Loads of Standoffs 34 lb Note:PV standoffs are staggered to ensure proper distribution of loading Roof Live Load=20 psf Note:Roof live load is removed in area's covered by PV array. Roof Dead Load(MP1-3) Composition Shingle 4.00 Roof Plywood 2.00 2x4 Top Chords @ 24"o.c. 0.73 Vaulted Ceiling 0.00 (Ceiling Not Vaulted) Miscellaneous 0.27 Total Roof DL(MP1-3) 7.0 psf DL Adjusted to 30 Degree Slope 8.1 psf Roof Dead Load(MP4) Composition Shingle 4.00 Roof Plywood 2.00 Double 2x4 Rafters @ 16"o.c. 2.19 Vaulted Ceiling 0.00 (Ceiling Not Vaulted) Miscellaneous 0.81 Total Roof DL(MP4) 9.0 psf DL Adjusted to 22 Degree Slope 9.71 Willey Fridley MN 2 Do M u S Domus Structural Engineering, LLC -S- T R U C T U R A I P.O. Box 560 Broomfield, CO 80038 N G I N E E R I n 6 1 T C 530-864-7055 projects@domusstruc.com Wind Calculations Per ASCE 7-16 Components and Cladding Input Variables Wind Speed 115 mph Exposure Category C Roof Shape Hip Roof Roof Slope 30 degrees Mean Roof Height 20 ft Effective Wind Area 21.1 ft Ground Elevation 0 ft Design Wind Pressure Calculations qh=0.00256*Kz*Kz1*Kd*Ke*V12 (Eq.26.10-1) Kz(Exposure Coefficient)=0.90 (Table 30.3-1) Kz1(topographic factor)= 1.00 (Fig.26.8-1) Kd(Wind Directionality Factor)= 0.85 (Table 26.6-1) Ke(Ground Elevation Factor)= 1.00 V(Design Wind Speed)= 115 mph (Fig.26.5-1A) Risk Category=11 (Table 1.5-1) qh= 25.95 Standoff Uplift Calculations-Portrait Zone 1 Zone 2 Zone 3 Positive ya= 0.78 0.80 0.80 0.78 GCp= -1.19 -1.44 -1.99 0.63 (Fig.30.3) Uplift Pressure= -24.1 psf -30.0 psf -41.3 psf 12.9 psf (Eq.29.4-7) ASD Uplift Pressure= -14.5 psf -18.0 psf -24.8 psf 9.6 psf X Standoff Spacing= 2.00 2.00 1.33 Y Standoff Spacing= 5.65 2.82625 2.82625 Tributary Area= 11.31 5.65 3.77 Dead Load on attachment= 34 lb 17 lb 11 lb Footing Uplift(0.6D+0.6W)_ -143lb -91 lb -87lb Standoff Uplift Calculations-Landscape Zone 1 Zone 2 Zone 3 Positive ya= 0.74 0.80 0.80 0.74 GCp= -1.12 -1.40 -1.99 0.59 (Fig.30.3) Uplift Pressure= -21.6 psf -29.1 psf -41.3 psf 11.4 psf (Eq.29.4-7) ASD Uplift Pressure(0.6W)= -13.0 psf -17.5 psf -24.8 psf 9.6 psf X Standoff Spacing= 4.00 4.00 2.67 Y Standoff Spacing= 3.72 1.85875 1.85875 Tributary Area= 14.87 7.44 4.96 Dead Load on attachment= 44.61 22.31 14.87 Footing Uplift(0.6D+0.6W)_ -166 lb -116lb -1141b Standoff Uplift Check Maximum Design Uplift=-166 lb Standoff Uplift Capacity =450 lb 450 lb capacity>166 lb demand Therefore,OK Fastener Capacity Check I 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 667.2 lb capacity>166 lb demand Therefore,OK Willey Fridley MN 3 Do M u S Domus Structural Engineering, LLC -S- T R U C T U R A I P.O. Box 560 Broomfield, CO 80038 N G I N E E R I n 6 1 T C 530-864-7055 projects@domusstruc.com Wind Calculations Per ASCE 7-16 Components and Cladding Input Variables Wind Speed 115 mph Exposure Category C Roof Shape Hip Roof Roof Slope 30 degrees Mean Roof Height 20 ft Effective Wind Area 21.1 ft Ground Elevation 0 ft Design Wind Pressure Calculations qh=0.00256*Kz*Kzl*Kd*Ke*V12 (Eq.26.10-1) Kz(Exposure Coefficient)=0.90 (Table 30.3-1) Kzl(topographic factor)= 1.00 (Fig.26.8-1) Kd(Wind Directionality Factor)= 0.85 (Table 26.6-1) Ke(Ground Elevation Factor)= 1.00 V(Design Wind Speed)= 115 mph (Fig.26.5-1A) Risk Category=11 (Table 1.5-1) qh= 25.95 Standoff Uplift Calculations-Portrait Zone 1 Zone 2 Zone 3 Positive ya= 0.80 0.80 0.80 0.80 GCp= -1.22 -1.46 -1.99 0.78 (Fig.30.3) Uplift Pressure= -25.3 psf -30.3 psf -41.3 psf 16.3 psf (Eq.29.4-7) ASD Uplift Pressure= -15.2 psf -18.2 psf -24.8 psf 9.8 psf X Standoff Spacing= 1.50 1.50 1.00 Y Standoff Spacing= 2.83 2.82625 2.82625 Tributary Area= 4.24 4.24 2.83 Dead Load on attachment= 13 lb 13 lb 8 lb Footing Uplift(0.6D+0.6W)_ -57lb -69lb -65lb Standoff Uplift Calculations-Landscape Zone 1 Zone 2 Zone 3 Positive ya= 0.80 0.80 0.80 0.80 GCp= -1.22 -1.46 -1.99 0.77 (Fig.30.3) Uplift Pressure= -25.3 psf -30.3 psf -41.3 psf 16.0 psf (Eq.29.4-7) ASD Uplift Pressure(0.6W)= -15.2 psf -18.2 psf -24.8 psf 9.6 psf X Standoff Spacing= 2.50 2.50 1.67 Y Standoff Spacing= 1.86 1.85875 1.85875 Tributary Area= 4.65 4.65 3.10 Dead Load on attachment= 13.94 13.94 9.29 Footing Uplift(0.6D+0.6W)_ -62lb -76 lb -71 lb Standoff Uplift Check Maximum Design Uplift=-76 lb Standoff Uplift Capacity = 135 lb 135 lb capacity>76 lb demand Therefore,OK Fastener Capacity Check Fastener=6-#12 Wood Screws Number of Fasteners=6 Embedment Depth=0.5 Pullout Capacity Per Screw= 177 lb Fastener Capacity= 1062 lb w/F.S.of 3=354 lb 354 lb capacity>76 lb demand Therefore,OK Willey Fridley MN 4 Do M t? S Domus Structural Engineering, LLC �7 TR1) CTURA1, P.O. Box560 Broomfield, CO 80038 -�- N Ci T NEER T N G T T. U. 530-864-7055 projects@domusstruc.com Framing Check (MP1-3) PASS w=93plf Dead Load 8.1 psf PV Load 3.5 psf Snow Load 35.0 psf 2x4 Top Chords @ 24"o.c. 0 0 Governing Load Combo=DL+SL Member Span=6'-0" Total Load 46.5 psf Member Properties Member Size S(in A3) 1(in A4) Lumber Sp/Gr Member Spacing 2x4 3.06 5.36 DF#2 @ 24"o.c. F = Check Bending Stress Fb(psi)= fb 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 Maximum Moment = (wLA2)/8 = 418.923 ft# = 5027.077 in# Actual Bending Stress=(Maximum Moment)/S =1641.5 psi Allowed>Actual--92%Stressed -- Therefore,OK Check Deflection Allowed Deflection(Total Load) = U180 (E=1600000 psi Per NDS) = 0.4 in Deflection Criteria Based on = Continuous Span Actual Deflection(Total Load) _ (w'LA4)/(185'E'I) = 0.132 in = U546 > L/180 Therefore OK Allowed Deflection(Live Load) = U240 0.3 in Actual Deflection(Live Load) _ (w'LA4)/(185'E'I) 0.099 in L/728 > L/240 Therefore OK Check Shear _ Member Area=5.3 inA2 Fv(psi)= 180 psi (NDS Table 4A) Allowed Shear = Fv'A = 945 lb Max Shear(V)=w L/2 = 279 lb Allowed>Actual--29.6%Stressed -- Therefore,OK Willey Fridley MN 5 Do M t? S Domus Structural Engineering, LLC �7 TR1) CTURA1, P.O. Box560 Broomfield, CO 80038 -�- N Ci T NEER T N G T VC 530-864-7055 projects@domusstruc.com Framing Check (MP4) PASS-With Framing Upgrades w=64plf Dead Load 9.7 psf PV Load 3.5 psf Snow Load 35.0 psf Double 2x4 Rafters @ 16"o.c. 0 Governing Load Combo=DL+SL Member Span=10'-3" ` Total Load 48.2 psf Member Properties-Based on Upgraded Section Member Size S(in A3) 1(in A4) Lumber Sp/Gr Member Spacing Double 2x4 6.13 10.72 DF#2 @ 16"o.c. Check Bending Stress Fb(psi)= fb 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 Maximum Moment = (wLA2)/8 =843.4928 ft# = 10121.91 in# Actual Bending Stress=(Maximum Moment)/S =1652.6 psi Allowed>Actual-92.6%Stressed -- Therefore,OK Check Deflection a Allowed Deflection(Total Load) = L/120 (E=1600000 psi Per NDS) = 1.025 in Deflection Criteria Based on = Simple Span Actual Deflection(Total Load) _ (5'w'LA4)/(384'E'I) =0.931 in = L/133 > L/120 Therefore OK Allowed Deflection(Live Load) = L/180 0.683 in Actual Deflection(Live Load) _ (5'w'LA4)/(384'E'I) 0.677 in L/182 > L/180 Therefore OK Check She Member Area= 10.5 inA2 Fv(psi)= 180 psi (NDS Table 4A) Allowed Shear = Fv'A = 1890 lb Max Shear(V)=w'L/2 = 329 lb Allowed>Actual--17.5%Stressed -- Therefore,OK Willey Fridley MN 6 n M us Domus Structural Engineering, LLC J TR1) CTURAL P.O. Box560 -�: N G 1 NEER i N G 1. 1. C. Broomfield, CO 80038 530-864-7055 projects@domusstruc.com Appendix A:General Notes GENERAL • 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,LLC of any discrepancies. • All report conclusions represent Domus Structural Engineering,LLC's best professional judgment based upon industry standards. • Resolve any conflicts on the drawings with Domus Structural Engineering,LLC before proceeding with construction. • 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. • A site visit was not physically conducted by Domus Structural Engineering,LLC.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. • Domus Structural Engineering,LLC 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,LLC harmless of any and all such claims. • Any and all waterproofing shall be provided by the contractor.Domus Structural Engineering,LLC is not responsible for waterproofing. • All hardware shall be installed per manufacturer specifications and within specified design limitations.Domus Structural Engineering,LLC assumes no responsibility for incorrectly installed hardware or hardware installed outside of the manfacturer specifications. USER RELIANCE Domus Structural Engineering,LLC 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,LLC.Third parties that obtain this report,or the information within shall have no rights of recourse or recovery against Domus Structural Engineering,LLC,it's officers or employees. ROOF MOUNTED ARRAYS • 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. • No structural members can be cut for conduit,etc.,unless specifically shown.Obtain prior written approval for installation of any additional conduit,etc. • 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. • 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,LLC if additional load has been added to the structure already. • Flexible utility connections must be used at any building seismic joint. • Care should be taken to ensure that PV arrays do not preclude drainage of rain water. • 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. • All lags orwood screws at the roof shall be stainless steel and installed withing the middle 1/3 of the dimensional width of the framing members. • 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. • Domus Structural Engineering,LLC 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,LLC. Willey Fridley MN 7