Report (2) o m u s Domus Structural Engineering, LLC
RECEIVED P.O. Box 6986
OCT1 � Broomfield, CO 80021
-E` N G T N E F, R I N G 1, 1, C 530-864-7055
CITY OF TIGARD Domusstructural@gmail.com
September 16,2021
To: Ion Solar
4801 N.University Ave.Suite 900
Provo,UT.84604
Subject: Certification Letter OFFICF Copy
Massarello Residence
14785 SW 81st Street Ave
Tigard,OR.97224
To Whom It May Concern,
A jobsite observation of the condition of the existing framing system was performed by an audit team of Ion 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 structure of(RS1)consists of composition shingle on roof plywood that is supported by 2x4 rafters @ 24"o.c.with
ceiling joists acting as rafter ties.The rafters have a max projected horizontal span of 8'-6",with a slope of 24 degrees.The
rafters are connected at the ridge to a ridge board and are supported at the eave by a load bearing wall.
The roof structure of(RS2)consists of composition shingle on roof plywood that is supported by nominal 2x4 rafters @ 24"o.c.
with ceiling joists acting as rafter ties.The rafters have a max projected horizontal span of 8'-3",with a slope of 24 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 system of(RS1)is 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(RS2)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(RS2)on all rafters that directly support solar
PV.Stitch new 2x4 DF#2(min)to existing member with Simpson SDW 22300 screws @ 16"o.c.or 10d nails @ 6"o.c..Lap as
{ needed with 4'-0"lap per attached detail.
I The spacing of the solar standoffs should be kept at 48"o.c.for landscape and 48"o.c.for portrait orientation,with a staggered
4
j 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.
Massarello Residence Tigard OR.xlsm 1
D o m t? s Domus Structural Engineering, LLC
P.O. Box 6986
'�' � C' �• �� ' �s Broomfield, CO 80021
EN G. I N 1: l' It i h Ci I. I. C: 530-864-7055
DomusstructuraI@gmail.com
Design Criteria:
• Applicable Codes=2019 OSISC&2017 ORSC,ASCE 7-16
• Roof Dead Load=7 psf(RS1) -- 8 psf(RS2)
• Roof Live Load=20 psf
• Wind Speed=96 mph(Vult),Exposure C
• Ground Snow Load=25 psf - Roof Snow Load=20 psf
• Attachment:1-5/16 dia.lag screw with 2.5 inch min.embedment
depth,at spacing shown above.
Please contact me with any further questions or concerns regarding this project.
Sincerely,
John Calvert,P.E. Q.E1) PROFe
Project Engineer w� �NG'jNFF,Q /O'L
345PE 9�
OREGO
16,2�J�Q�
A. CP
Digitally signed by
John A. Calvert
Exp:12/31/21 Date: 2021.09.17
08:55:37 -06'00'
Massarello Residence Tigard OR.xlsm 2
-1X DECKING OR SHEATHING
(N) INSTALL SIMPSON A34 CLIP.
(E) RAFTERS
(N) SISTER MEMBER TO BE FULL
LENGTH.ATTACH TO(E)RAFTER W/
SIMPSON SDW22300 SCREWS
STAGGERED TOP AND BOTTOM @
16"O.C.
MINIMALLY NOTCH NEW (E) CEILING JOIST
SISTER RAFTER TO BEAR
DIRECTLY ON(E)TOP PLATE
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/
SIMPSON SDW22300 SCREWS
STAGGERED TOP AND BOTTOM @
16"O.C.
MINIMALLY NOTCH NEW (E) CEILING JOIST
SISTER RAFTER TO BEAR QED PRro)
DIRECTLY ON(E)TOP PLATE
OF WALL. ��Gj ��GINE�cR io2
OPTION 2 - OVERLAPPED SISTER ��' 345PE
SEE LETTER FOR UPGRADE LAP LENGTH AND SIZE.
(N) SISTER RAFTER
OREGO
Liz A. C
(N) SISTER RAFTER (E) RAFTER
SECTION A-A Exp:12/31/21
E
SISTER UPGRADE OPTIONS
PROJECT NAME: Rafter sister upgrade Scale: N.T.S.
Domus Structural Engineering, LLC. Date:4/5/18
P.O.BOX 6986 Project Number:Solar PV
Broomfield, CO 80021 Project Description: Rafter sister upgrade detail and Drawn By:JAC Drawing Name:
(530) 864-7055 specifications. Revisions:
Domusstructural@gmail.com A S I S 1
B
Domus Structural Engineering, LLC
D o m T T s P.O. Box 6986
Broomfield, CO 80021
S ]' K [' (: T [' K A 1~ 530-864-7055
E N C► T ':`` E E R T N G i. T. {: Domusstructural@gmail.com
Gravity Loading
Roof Snow Load Calculations
p9=Ground Snow Load= 25 psf
pf=0.7 Ce Cf I p9 (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= 20.0 psf
ps=CSpf (ASCE7-Eq 7-2)
Cs=Slope Factor= 1
p5=Sloped Roof Snow Load= 20.0 psf
PV Dead Load=3 psf(Per Ion Solar)
DL Adjusted to 24 Degree Slope 3.28 psf
PV System Weight
Weight of PV System(Per Ion Solar) 3.0 psf
X Standoff Spacing= 4.00 ft
Y Standoff Spacing= 3.00 ft
Standoff Tributary Area= 12.00 sft
Point Loads of Standoffs 36 Ib
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(RS1)
Composition Shingle 4.00
Roof Plywood 2.00
2x4 Rafters @ 24"o.c. 0.73
Vaulted Ceiling 0.00 (Ceiling Not Vaulted)
Miscellaneous 0.27
Total Roof DL(RS1) 7.0 psf
DL Adjusted to 24 Degree Slope 7.7 psf
Roof Dead Load(RS2)
Composition Shingle 4.00
Roof Plywood 2.00
Double 2x4 Rafters @ 24"o.c. 1.46
Vaulted Ceiling 0.00 (Ceiling Not Vaulted)
Miscellaneous 0.54
Total Roof DL(RS2) 8.0 psf
DL Adjusted to 24 Degree Slope 8.76
Massarello Residence Tigard OR xlsm 3
Do m(` 5 Domus Structural Engineering,LLC
P.O.Box 6986
Broomfield,CO 80021
Ci I N E E I2 I N Cr 1. 1=C. 530-864-7055
Domusstructural@gmail.com
Wind Calculations
Per ASCE 7-16 Components and Cladding
Input Variables
Wind Speed 96 mph
Exposure Category C
Roof Shape Gable Roof
Roof Slope 24 degrees
Mean Roof Height 20 It
Effective Wind Area 20.1 ft
Ground Elevation 0 ft
Design Wind Pressure Calculations
ch=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)=96 mph (Fig.26.5-1A)
Risk Category=II (Table 1.5-1)
qh= 18.09
Standoff Uplift Calculations-Portrait
Zone 1 Zone 2 Zone 3 Positive
Ye= 0.77 0.77 0.80 0.77
GCp= -1.50 -2.41 -3.11 0.52 (Fig.30.3)
Uplift Pressure= -21.0 psf -33.7 psf -44.9 psf 7.2 psf (Eq.29.4-7)
ASD Uplift Pressure= -12.6 psf -20.2 psf -27.0 psf 9.6 psf
X Standoff Spacing= 4.00 4.00 2.67
Y Standoff Spacing= 3.00 3 3
Tributary Area= 12.00 12.00 8.00
Dead Load on attachment= 36 Ib 36 Ib 24 Ib
Footing Uplift(0.6D+0.6W)_ -129 Ib -221 Ib -201 Ib
Standoff Uplift Calculations-Landscape
Zone 1 Zone 2 Zone 3 Positive
Ya= 0.80 0.80 0.80 0.80
GCp= -1.50 -2.50 -3.52 0.70 (Fig.30.3)
Uplift Pressure= -21.7 psf -36.2 psf -51.0 psf 10.1 psf (Eq.29.4-7)
ASD Uplift Pressure(0.6W)= -13.0 psf -21.7 psf -30.6 psf 9.6 psf
X Standoff Spacing= 4.00 4.00 2.67
Y Standoff Spacing= 1.67 1.67 1.67
Tributary Area= 6.68 6.68 4.45
Dead Load on attachment= 20.04 20.04 13.36
Footing Uplift(0.6D+0.6W)_ -75 Ib -133 Ib -128 Ib
Standoff Uplift Check
Maximum Design Uplift=-221 Ib
Standoff Uplift Capacity =360 Ib
360 Ib capacity>221 Ib demand Therefore.OK
Fastener Capacity Check
Fastener= c oia lao
Number of Fasteners=1
Embedment Depth=2.5
Pullout Capacity Per Inch= 250 Ib
Fastener Capacity=625 Ib
w/F.S.of 1.5&DOL of 1.6=667 Ib
667.2 Ib capacity>221 Ib demand Therefore OK
Massarello Residence Tigard OR.xism 4
COMPANY PROJECT
WoodWorkso
SOFTWARE FOR WOOD DESIGN
Aug. 30, 2021 14:38 Beam1.wwb
Design Check Calculation Sheet
WoodWorks Sizer 11.1
Loads:
Load Type Distribution Pat- Location [ft] Magnitude Unit
tern Start End Start End
DL Dead Full Area No 7 .00 (24 .0") psf
Snow Snow Full Area Yes 20.00 (24 .0") psf
PV Dead Full Area No 3.00 (24 .0") psf
Maximum Reactions (lbs), Bearing Capacities (lbs) and Bearing Lengths (in)
14.747'
1' 5' 13.479'
Unfactored•
Dead 37 178 78
Snow 93 332 145
Factored:
Total 130 510 223
Bearing:
F'theta 691 691 691
Capacity
Joist 908 908 519
Support 586 586 586
Des ratio
Joist 0.14 0.56 0.43
Support 0.22 0.87 0.38
Load comb #5 #8 #7
Length 0.50* 0.50* 0.50*
Min req'd 0.50* 0.50* 0. 50*
Cb 1.75 1.75 1.00
Cb min 1.75 1.75 1.00
Cb support 1.25 1.25 1 .25
Fcp sup 625 625 625
"Minimum bearing length setting used: 1/2"for end supports and 1/2" for interior supports
Maximum reaction on at least one support is from a different load combination than the critical one for bearing design,
shown here, due to Kd factor. See Analysis results for reaction from critical load combination.
Lumber-soft, D.Fir-L, No.2, 2x4 (1-1/2"x3-1/2")
Supports: All -Timber-soft Beam, D.Fir-L No.2
Roof joist spaced at 24.0"c/c; Total length: 14.75'; Clear span: 1.061', 4.288', 9.141'; volume = 0.5 cu.ft.; Pitch: 5/12
Lateral support: top=full, bottom= at all supports; Repetitive factor: applied where permitted (refer to online help);
FTI
WoodWorks® Sizer SOFTWARE FOR WOOD DESIGN
Beaml.wwb WoodWorks®Sizer 11.1 Page 2
Analysis vs. Allowable Stress and Deflection using NDS 2015 :
Criterion Analysis Value Design Value Unit Analysis/Design
Shear fv = 77 Fv' = 207 psi fv/Fv' = 0.37
Bending(+) fb = 1461 Fb' = 1785 psi fb/Fb' = 0.82
Bending(-) fb = 1617 Fb' = 1649 psi fb/Fb' = 0. 98
Live Defl'n 0.37 = L/297 0. 61 = L/180 in 0. 61
Total Defl'n 1 0.66 = L/166 1 0. 92 = L/120 in 0.72
Additional Data:
FACTORS: F/E(psi) CD CM Ct CL CF Cfu Cr Cfrt Ci Cn LC#
Fv' 180 1.15 1.00 1.00 - - - - 1.00 1.00 1.00 2
Fb'+ 900 1.15 1.00 1.00 1.000 1.500 1.00 1.15 1.00 1.00 - 7
Fb'- 900 1 . 15 1.00 1.00 0.923 1.500 1.00 1.15 1.00 1 .00 - 8
Fcp' 625 - 1. 00 1.00 - - - - 1. 00 1.00 - -
E' 1.6 million 1.00 1.00 - - - - 1.00 1.00 - 7
Emin' 0.58 million 1.00 1.00 - - - - 1.00 1.00 - 7
CRITICAL LOAD COMBINATIONS:
Shear : LC #2 = D+S, V max = 286, V design = 270 lbs
Bending(+) : LC #7 = D+S (pattern: SsS) , M = 373 lbs-ft
Bending(-) : LC #8 = D+S (pattern: sSS) , M = 413 lbs-ft
Deflection: LC #7 = (live)
LC #7 = (total)
D=dead L=live S=snow W=wind I=impact Lr=roof live Lc=concentrated E=earthquake
All LC's are listed in the Analysis output
Load Patterns: s=S/2, X=L+S or L+Lr, _=no pattern load in this span
Load combinations: ASCE 7-10 / IBC 2015
CALCULATIONS:
Deflection: EI = 8.57e06 lb-in2
"Live" deflection = Deflection from all non-dead loads (live, wind, snow...)
Total Deflection = 1.50 (Dead Load Deflection) + Live Load Deflection.
Bearing: Allowable bearing at an angle F'theta calculated for each support
as per NDS 3. 10.3
Lateral stability(-) : Lu = 9.19' Le = 14 . 13' RB = 16.2; Lu based on full span
Design Notes:
1. WoodWorks analysis and design are in accordance with the ICC International Building Code (IBC 2015), the National
Design Specification (NDS 2015), and NDS Design Supplement.
2. Please verify that the default deflection limits are appropriate for your application.
3. Continuous or Cantilevered Beams: NDS Clause 4.2.5.5 requires that normal grading provisions be extended to the
middle 2/3 of 2 span beams and to the full length of cantilevers and other spans.
4. Sawn lumber bending members shall be laterally supported according to the provisions of NDS Clause 4.4.1.
5. SLOPED BEAMS: level bearing is required for all sloped beams.
6. The critical deflection value has been determined using maximum back-span deflection. Cantilever deflections do not
govern design.
e
�T� Domus Structural Engineering, LLC
1:� o m t f s P.O. Box 6986
C ,i, R C T T, R A1 Broomfield, CO 80021
530-864-7055
ENT CJ 1 N E E R T 1\ G T. 1. t, Domusstructural@gmail.com
Framing Check
(RS2) PASS•With Framing Upgrades
w=64 plf
Dead Load 8.8 psf
PV Load 3.3 psf
Snow Load 20.0 psf Double 2x4 Rafters @ 24"o.c.
Governing Load Combo=DL+SL Member Span=8'-3"
Total Load 32.0 psf
Member Properties-Based on Upgraded Section
Member Size S(in"3) 1(in^4) Lumber Sp/Gr Member Spacing
Double 2x4 6.13 10.72 DF#2 @ 24"o.c.
Check Bending Stress
Fb(psi)= fb x Cd x Cf ;c Cr (NDS Table 4.3.1)
900 x 1.15 x 1.5 x 1.15
Allowed Bending Stress=1785.3 psi
Maximum Moment = (wL^2)/8
= 545.1976 ft#
= 6542.371 in#
Actual Bending Stress=(Maximum Moment)/S
= 1068.2 psi
Allowed>Actual-59.9%Stressed -- Therefore,OK
Check Deflection
Allowed Deflection(Total Load) = Li'.I (E= 1600000 psi Per NDS)
= 0.55 in
Deflection Criteria Based on = Simple Span
Actual Deflection(Total Load) _ (5-w-L^4)/(384*E`I)
= 0.390 in
= U254 > U180 Therefore OK
Allowed Deflection(Live Load) = L/240
0.412 in
Actual Deflection(Live Load) _ (5"w-L"4)/(384*E-I)
0.244 in
U406 > U240 Therefore OK
Check Shear
Member Area= 10.5 in12 Fv(psi)= 180 psi (NDS Table 4A)
Allowed Shear = Fv'A = 1890 Ib Max Shear(V)=w`L/2 = 264 Ib
Allowed>Actual--14%Stressed -- Therefore,OK
Massarelln Residence Tinard OR Asm 5
j� Domus Structural Engineering, LLC
1:_�+ o !t� C J s P.O. Box 6986
SBroomfield, CO 80021
`I' R C.` (, T C."' R A I, 530-864-7055
E N G T N 1- F. R 1 >ti G 1. 1, C' ateral Check Domusstructural@gmail.com
L
Existing Weight of Effected Building
Level Area Weight(psf) Weight(lb)
Roof 1244 sf 7.7 psf 9532 Ib
Ceiling 1244 sf 6.0 psf 7464 Ib
Wood Siding 100 ft 5.0 psf 2000 Ib (8'-0"Wall Height)
Int.Walls 100 ft 6.4 psf 2560 Ib
Existing Weight of Effected Building 21556 lb
Proposed Weight of PV System
Weight of PV System(Per Ion Solar) 3.0 psf
Approx.Area of Proposed PV System 241 sf
Approximate Total Weight of PV System 723 Ib
10%Comparison
10%of Existing Building Weight(Allowed) 2156 Ib
Approximate Weight of PV System(Actual) 723 Ib
Percent Increase 3.4%
2156 Ib>723 Ib,Therefore OK
t
Y
Massarelln Residence Tigard OR Asm 6