HomeMy WebLinkAboutIsabel Pinguil Engineering Letter (2) Domus Domus Structural Engineering, LLC
7- TR1) CTURA1. P.O. Box560
Broomfield, CO 80038
-�- N G 1 N E E R i N G, 1. 1. C 530-864-7055
projects@domusstruc.com
December 6,2023
To: Blue Raven Solar
1403 North Research Way,Building J
Orem,UT.84097
Subject: Certification Letter
Pinguil Residence
5284 Taylor St NE
Minneapolis,MN.55421
To Whom It May Concern,
A jobsite 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&2)consist of composition shingle on roof plywood that is supported by 2x8 rafters @ 16"o.c..The
rafters support a vaulted ceiling and have a max projected horizontal span of 13'-6",with a slope of 18 degrees.The rafters are
supported at the ridge by a ridge beam and at the eave by a load bearing wall.
The existing roof framing systems of(MP1&2)are judged to be adequate to withstand the loading imposed by the installation of
the solar panels.No reinforcement is necessary.
The spacing of the solar standoffs should be kept at 48"o.c.for landscape and 32"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:
• Applicable Codes=2020 Minnesota Building Code,ASCE 7-16 CA
• Roof Dead Load=13 psf(MP1&2) ;` ��P........ '/ ell
• Roof Live Load=20 psf •,
• Wind Speed=115 mph(Vult),Exposure C _ ICEN ID
• Ground Snow Load=50 psf - Roof Snow Load=35 psf = I
• Attachment:1-5/16 dia.lag screw with 2.5 inch min.embedment ENCs E
depth,at spacing shown above. 52$23
T• •. .�Q:
Please contact me with any further questions or concerns regarding this project. tc••., •••••'N�(�
pF�MLo"%
Sincerely,
I hereby certify that this plan,specification or report was prepared by me Digitally signed by
or under my direct supervision and that I am a duly Licensed Professional John A.Calvert
Engineer under the laws of the State of Minnesota.John A.Calvert,
John Calvert,P.E. License No.52823 Expiration Date:30-June-2024 Date:2023.12.06
Project Engineer 11:20:50-07'00'
Pinguil Minneapolis MN 1
Do M u S Domus Structural Engineering, LLC
7- T R 1) C T U R A 1, P.O. Box 560
Broomfield, CO 80038
-�- N G T N F F. R i N G, 1. 1. C; 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
ps=Sloped Roof Snow Load= 35.0 psf
�oad=2.5 psf(Per Blue Raven Solar
DL Adjusted to 18 Degree Slope 2.63 psf
PV System Weight
Weight of PV System(Per Blue Raven Solar) 2.5 psf
X Standoff Spacing= 2.67 ft
Y Standoff Spacing= 6.08 ft
Standoff Tributary Area= 16.22 sft
Point Loads of Standoffs 41 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&2)
Composition Shingle 4.00
Roof Plywood 2.00
2x8 Rafters @ 16"o.c. 2.27
Vaulted Ceiling 4.00
Miscellaneous 0.73
Total Roof DL(MP1&2) 13.0 psf
DL Adjusted to 18 Degree Slope 13.7 psf
Pinguil Minneapolis MN 2
Do m u S Domus Structural Engineering, LLC
S T R U C T U R A 1. P.O. Box 560
Broomfield, CO 80038
E N c i n r ER r N C, LLC 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 Gable Roof
Roof Slope 18 degrees
Mean Roof Height 20 ft
Effective Wind Area 21.3 ft
Ground Elevation 0 ft
Design Wind Pressure Calculations '
qh=0.00256'Kz'Kzt'Kd'Ke'V^2 (Eq.26.10-1)
Kz(Exposure Coefficient)= 0.90 (Table 30.3-1)
Kzt(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
Y.= 0.73 0.80 0.80 0.73
GCp= -2.00 -3.00 -3.60 0.49 (Fig.30.3)
Uplift Pressure= -37.9 psf -62.3 psf -74.7 psf 9.2 psf (Eq.29.4-7)
ASD Uplift Pressure= -22.7 psf -37.4 psf -44.8 psf 9.6 psf
X Standoff Spacing= 2.67 2.67 1.78
Y Standoff Spacing= 6.08 3.04166667 3.04166667
Tributary Area= 16.22 8.11 5.41
Dead Load on attachment= 41 lb 201b 141b
Footing Uplift(0.6D+0.6W)_ -3441b -291 lb -2341b
Standoff Uplift Calculations-Landscape
Zone 1 Zone 2 Zone 3 Positive
Y.= 0.75 0.80 0.80 0.75
GCp= -2.00 -3.00 -3.60 0.50 (Fig.30.3)
Uplift Pressure= -39.0 psf -62.3 psf -74.7 psf 9.8 psf (Eq.29.4-7)
ASD Uplift Pressure(0.6W)= -23.4 psf -37.4 psf -44.8 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= 35.00 17.50 11.67
Footing Uplift(0.6D+0.6W)_ -3061b -251 lb -2021b
Maximum Design Uplift=-344 lb
Standoff Uplift Capacity = 450 lb
450 lb capacity>344 lb demand Therefore,OK
Fastener Capacity Check
Fastener= 1-5/16"dia.lag
Number of Fasteners= 1
Embedment Depth=2.5
Pullout Capacity Per Inch= 2501b
Fastener Capacity=6251b
w/F.S.of 1.5&DOL of 1.6=6671b
667.2 lb capacity>344 lb demand Therefore,OK
Pinguil Minneapolis MN 3
Do M u S Domus Structural Engineering, LLC
7- T R 1) C T U R A 1, P.O. Box 560
Broomfield, CO 80038
-�- N G T N F F. R i N G, 1. 1. C; 530-864-7055
projects@domusstruc.com
Framing Check
(MP1&2) PASS
w=68plf
Dead Load 13.7 psf
PV Load 2.6 psf
Snow Load 35.0 psf 2x8 Rafters @ 16"o.c.
0 O
Governing Load Combo=DL+SL Member Span=13-6"
Total Load 51.3 psf
T Member Properties
Member Size S(in A3) 1(in A4) Lumber Sp/Gr Member Spacing
2x8 13.14 47.63 DF#2 @ 16"o.c.
Fb(psi)= fb x Cd x Cf x Cr (NDS Table 4.3.1)
900 x 1.15 x 1.2 x 1.15
Allowed Bending Stress=1428.3 psi
Maximum Moment =(wLA2)/8
= 1558.167 ft#
= 18698 in#
Actual Bending Stress=(Maximum Moment)/S
=1423 psi
Allowed>Actual--99.7%Stressed -- Therefore,OK
heck Deflection
Allowed Deflection(Total Load) = L/180 (E=1600000 psi Per NDS)
=0.9 in
Deflection Criteria Based on = Simple Span
Actual Deflection(Total Load) _ (5'w'LA4)/(384'E'I)
=0.671 in
= L/242 > L/180 Therefore OK
Allowed Deflection(Live Load) = L/240
0.675 in
Actual Deflection(Live Load) _ (5'w'LA4)/(384'E'I)
0.458 in
L/354 > L/240 Therefore OK
Check Shear L
Member Area= 10.9 inA2 Fv(psi)= 180 psi (NDS Table 4A)
Allowed Shear = Fv"A = 1958 lb Max Shear(V)=w L/2 = 462 lb
Allowed>Actual--23.6%Stressed -- Therefore,OK
Pinguil Minneapolis MN 4
Domus
Domus Structural Engineering, LLC
CJ TR1) CTURA1, P.O. Box560
-E N G T NEER i N G T. 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.
Pinguil Minneapolis MN 5