REVIEWED BLD BLD2024-0666+Structural_Calculations+5.16.2024_1.58.51_PM+4262646BLD2024-0666
South Valley Engineering
4742 Liberty Rd. S #151 • Salem, OR. 97302
Ph. (503) 302-7020 • Fax (888) 535-6341
www.southvalleyengineering.com
Protect No.
12404049
Calculations for
Susan Weller
720 Cedar Street
Edmonds, WA. 98020
Date
5/16/2024
Engineer
RECEIVED
May 17 2024
CITV OF EDMONDS
DEVELOPMENT SERVICES
DEPARTMENT
.,.,.,.,.,.,.,.,.,.,.
REVIEWED,
BY
CITY OF EDMONDS
BUILDING DEPARTMENT
POST FRAME BUILDING SUMMARY SHEET
Owner: Susan Weller Date: 5/16/2024
Building location: 720 Cedar Street
Edmonds, WA. 98020 Project No.: 12404049
Building Description: Private shop Building Codes: 2021 IBC ASCE 7-16
Building dimensions:
Width:
25
ft.
Length:
24
ft.
Height:
10
ft.
Eave overhang:
1.5
ft.
Gable overhang:
1.5
ft.
Roof pitch:
4
/12
Bay spacing:
12
ft.
Post tributary width:
12
ft.
Concrete Slab:1 Yes
Post & posthole information:
Eave wall posts:
Size:
6x6
Grade:
#2 H-F
Type:
RS'
Posthole diameter:
24 in
Posthole depth":
4.00 ft.
Post Constraint/backfill:
Purlin & girt information:
Slab w/ granular
backfill
'Rough Sawn
"To bottom of footing
Environmental information:
Wind speed:
110
MPH
Wind exposure:
B
Seismic design category:
D
Ss:
1.28
SJ:
0.45
Ground snow load:
25
psf.
Design Snow Load:
25
psf.
Roof dead load:
3
psf. (incl. ceiling load if any)
Soil bearing capacity:
1,500
psf.
Risk Category:
II
Per Table 1.5-1
ASCE 7-16
Gable wall posts:
Size:
6x6
Grade:
#2 H-F
Type:
RS'
Posthole diameter:
24
in
Posthole depth":
4.00
ft.
Post Constraint/backfill: Slab w/ granular
backfill
'Rough Sawn
"To bottom of footing
Purlins
Size:
Grade:
Spacing:
2x6
Girts
Size: 2x6
Grade: #2 D F
in. o.c. Spacing: 24 in. o.c.
Orientation: Flat
#2 D-F
24
Sheathing information:
Roof: 29 ga. Metal only
Walls: All walls are 29 ga. metal only
Page 1 of 12
Snow Load Calculations
Snow load calculations per ASCE 7-16 Chapter 7
pg: 25 psf - Ground Snow Load
Ce: 1.0 Exposure Factor from ASCE Table 7-2
Ct: 1.2 Thermal Factor from ASCE Table 7-3
Is: 1.0 Importance Factor from ASCE Table 1.5-2
Flat Roof Snow Load, pf = 0.7 x pg X Ce x Ct x IS
pf: 21.0 psf - Flat Roof Snow Load
Cs: 0.95 Figure 7.4-1 based on Ct, roof slope and surface
ps: 19.9 psf-Sloped roof snow load
Nesign: 25 psf-Design Snow Load
Page 2 of 12
Wind Pressure Calculations
Wind calculations per ASCE 7-16 Chapters 26, 28 and 30
Roof Pitch: 4 /12 Design Wind Speed, V:j 110 IMPH
Eave Height: 10 ft. Wind Exposure: B Risk Category: II
Velocity pressures qh per equation 26.10-1
qh=0.00256xKhxKZtxKdxKexV2 at mean roof height h
Angle: 18.43 °
Kh: 0.70 Velocity pressure coefficient at roof ht. h from Table 26.10-1
KZt: 1.00 Topographic effect -assume no ridges or escarpments
Kd: 0.85 Wind Directionality Factor, Table 26.6-1
Ke: 1.00 Ground Elevation Factor, Table 26.9-1
Velocity Pressures: qh= 18.43 psf
Determine Velocity Pressure Coefficients & Wind Pressures per ASCE 7-16 Figure 28.3-1 for MWFRS
MWFRS
1. Windward Eave Wall Pressure 2. Leeward Eave Wall:
GCpfww: 0.52 GCpfwr: -0.42
qww: 9.52 psf I I q1w: -7.66 psf
3. Windward Eave Roof Pressure
GCpfwr -0.69
qwr: -12.72 psf
5. Windward Gable Wall:
GCpfw9: 0.40
q1w: 7.37 psf
Components & Claddin
4. Leeward Eave Roof:
GCpflr: -0.47
q1r: -8.64 psf
6. Leeward Gable Wall:
Cpfwg: -0.29
q1w: -5.34 psf
GCp;: 0.18 Internal pressure per Table 26.13-1
7. Roof elements
GCpr: -0.82
qer: 18.47 psf Roof elements per Figure 30.3-2A thru I
8. Wall elements:
GC w: -0.96
qer: 20.95 psf Wall elements per Figure 30.3-1
Page 3 of 12
Seismic Design Parameters
Calculate seismic building loads from ASCE 7-16 Chapter's 11 & 12
Seismic Parameters
Ss= 1.28 S1= 0.45
Fa= 1.00 F = 1.85 per Tables 11.4-1 & 11.4-2
SMS= 1.28 SM1= 0.83 Calculated per Section 11.4.3
SDS= 0.86 SD1= 0.56 Calculated per Section 11.4.4
Seismic Design
Category= D From Section 11.6 Importance factor: 1.00
F= 1.0 for 1 story building
Response Mod. Factor R:
Roof: 2.5 From Table 12.14-1, Section B-24
Left gable wall: 2.5 From Table 12.14-1, Section B-24
Right gable wall: 2.5 From Table 12.14-1, Section B-24
Front eave wall: 2.5 From Table 12.14-1, Section B-24
Rear eave wall: 2.5 From Table 12.14-1, Section B-24
Calculate building weights, W, for seismic forces
Building width= 25 ft. Building length= 24 ft. Building height= 10 ft.
Roof area= 756 sf Gable wall area= 177 sf Eave wall area= 120 sf
Roof + ceiling DL= 3 psf Snow LL (if appliable)= 0 psf Roof W= 2,268 Ibs
Loft (y/n): n Loft dead load: N/A psf Full or partial loft: N/A
Wall Areas Building dead loads Loft dead loads
Left gable wall: 177 SF Left gable wall: 3 psf Left gable wall: 0 Ibs
Right gable wall: 177 SF Right gable wall: 3 psf Right gable wall: 0 Ibs
Front eave wall: 120 SF Front eave wall: 3 psf Front eave wall: 0 Ibs
Rear eave wall: 120 SF Rear eave wall: 3 psf Rear eave wall: 0 Ibs
Calculate Seismic Base Shear, V per Section 12.14.8
V=[(FxSDs)/R]xW (Egn.12.14-12)
Total dead Ioads,W Oncl roof, loft)
Roof: 2,268 Ibs Vroof= 776 Ibs base shear for roof diaphragm
Left gable wall: 531 Ibs VLGw= 511 Ibs base shear for wall diaphragm
Right gable wall: 531 Ibs VRGw= 511 Ibs base shear for wall diaphragm
Front eave wall: 360 Ibs VFEw= 570 Ibs base shear for wall diaphragm
Rear eave wall: 360 Ibs VREW=l 570 Ibs base shear for wall diaphragm
Page 4 of 12
Diaahraam Stiffness Calculation
The diaphragm stiffness will be calculated based on the methodology from "Post Frame Building Design",
by John N. Walker and Frank E. Woeste. This method is widely accepted in the post frame industry for
determining metal diaphragm stiffness.
1. The diaphragm stiffness, c'= (Ext) / [2x(1+u) x (g/p) + (K2/(bxt)2)
Where: c'=
3130
Ibs/in = Diaphragm stiffness of the test panel (1992 Fabral Test for Grandrib III)
E=
2.75E+07
psi = Modulus of elasticity for metal sheathing
t=
0.017
in = Steel thickness for 29 ga metal sheathing
u=
0.3
= Poisson's ratio for steel
g/p=
1.085
= Ratio of steel corrugation pitch to steel sheet width
b=
144
in. = Length of test panel
K2=
-
= Sheet edge purlin fastening constant (unknown)
2. The diaphragm for the same metal for a different length b can be calculated with the above
above equation once the constant K2 is known. Solving for K2 yields:
K2 =[((Ext)x(bxt2))/c]-[2x(1+u)x(bxt)2x(g/p)
K2 = 878 in 4
3. The stiffness of the acutal panel will be calculated from equation in 1. above, based on its actual length, b'
Roof pitch= 4 /12 Building width= 25 ft 6= 18.43 ° roof angle
b'= 158.11 in = length of steel roof panel at the given angle for 1 /2 of the roof
c= 3759 Ibs/in - stiffness of actual roof diaphragm
4. Calculate the equivalent horizontal roof stiffness, ch for the entire roof
ch= 2xcx(cos26)x(b'/a) ch= 7,429 lb/in a= 144 in. post spacing
5. Calculate the stiffness, k, of the post frame, which is the load required for the top of the frame a distance, d
For d=1 ", k=P=(6xdxEpxlp)/L3
d= 1
in -deflection used to establish k
Ip= 108 in - Momentof inertia of post
Ep= 1.10E+06
psi - Modulus of elasticity of post
L= 108 in - Bending length of post
k= 566
Ibs/in
6. Determine the side sway force, mD from tables based on k/ch verses number of frames.
NF= 3 frames in building (including end walls)
mD= 0.96 = calculated stiffness of metal roof diaphragm
Since roof sheathing is metal, mD used for calculations is
k/ch= 0.0762
0.96
Page 5 of 12
Post Wind Load Calculation
Determine the bending stress on the post from the wind load
Windward wall wind pressure =
9.52 psf
Leeward wall wind pressure =
-7.66 psf
Total wind pressure =
17.17 psf
Total wall pressure
to use =
17.17 psf (10 psf min. per code)
L=
108
in
Bending length of the post
w=
17.17
pli
Distributed wind load on the post
MPo=
12,520
Ibf-in
Moment as a propped cantilever (w x L2) / (2 x 8)
fb_pc=
348
psi
Stress on the post from the distirbuted wall wind, = MPc / SX
R=
696
Ibf
Total side sway force = 3 x w x (L/8)
mD=
0.96
Stiffness coefficient from diaphragm stiffness calculation,
or 1.0 if wood sheathing in roof
Q=
670
Ibf
Side sway force resisted by the roof diaphragm = mD x R
wR=
16.6
pli
The total distributed wind load resisted by the roof diaphragm = 8 x ((Q/(3 x L))
wpost=
0.62
pli
The total distributed wind load NOT resisted by the roof diaphragm
for which the post must resist. Wpost = w - wR
Want=
3,622
Ibf-in
The moment in the post as a simple cantilever
= wosst x ((L2)/2) (This value is 0 if roof is a wood diaphragm)
(cant=
50
psi
The fiber stress in the post from simple cantilever stress
= Mcant/(2 x SX) (This value is 0 if roof is a wood diaphragm)
Mpost=
15,689
Ibf-in
The total moment in the post = (mD x MP.) + Mcant
fb-post=
386
psi
The total bending stress on the post = (mD x fb_pc) + fcant
Page 6 of 12
Post Desiqn
Determine the allowable bending and compression stresses for the eave wall posts per NDS
Nominal Design Values (allowable) Adjustment factors per Table 4.3.1
Fb: 575 psi -bending CD for snow 1.15 LDF for snow
Fr: 575 psi -compression CD for wind/seismic 1.6 LDF for wind/seismic
CD for post 1.0 Size factor for posts < 12" in depth
Final Design Values Cp= 0.89 Column stability factor per Section 3.7
Fb_design: 920 psi final allowable bending stress
Fc_design: 591 psi final allowable compression stress
Combined Bending And Compressive (CBAC) Post Loads by Load Case
Determine the maximum Combined Bending And Compressive stresses in the eave wall post per NDS 3.9.2
using applicable load cases from ASCE 7-16 Section 2.4.
Load Case 1 - Dead Load + Snow
Fb_design: 920 psi Final allowable bending stress
Fc_design: 591 psi Final allowable compression stress
Pdead= 504 Ibs Dead load
Psnow= 4200 Ibs Snow load
A= 36 sq-in Cross -sectional area of post FcE= 1,586 psi
fb= 0 psi=0 fc= 131 psi= (Psnow + Pdead)/A
CBAC1= 0.05=((fc/Fc_ design )2)+((fb/(Fb_design(1-(fc/FcE))))))
Load Case 2 - Dead Load + 0.6Wind
Fb_design: 920 psi Final allowable bending stress
Fc_design: 591 psi Final allowable compression stress
Pdead= 504 Ibs Dead load
Psnow= 4200 Ibs Snow load
A= 36 sq-in Cross -sectional area of post FcE= 1,586 psi
fb= 231 psi=0.6 x fb_post fc= 14 psi= Pdead/A
CBAC2= 0.25=((fc/Fc_design)2)+((fb/(Fb_design(1 (fc/FcE))))))
Load Case 3 - Dead Load + 0.75(0.6Wind) + 0.75Snow
Fb_design: 920 psi Final allowable bending stress
Fc_design: 591 psi Final allowable compression stress
Pdead= 504 Ibs Dead load
Psnow= 4200 Ibs Snow load
A= 36 sq-in Cross -sectional area of post FcE= 1,586 psi
fb= 173 psi=.75 x (0.6 x fb_post) fc= 102 psi = ((.75 x Psnow) + Pdead)/A
CBAC3= 0.23=((fc/Fc_design )2)+((fb/(Fb_design(1 -(fc/FcE))))))
Max. CBAC= 25% >> Maximum post usage < 100% OK
Page 7 of 12
Post Embedment Calculation
Determine the minimum posthole diameter and embedment depth for the eave wall posts
per ASAE EP486.1
Since there is a slab, the post will be considered constrained at the top.
The backfill will be compacted gravel or sand full depth unless otherwise required for shear wall uplift.
Design Criteria
SY= 1500 psf-vertical soil bearing capacity
S= 150 psf-lateral soil bearing capacity
Mosst= 784 ft-Ibs - Moment at top of one posthole
Va= 368 Ibs-Lateral load on post at top of posthole
Posthole dia.= 2 ft.
b= 0.71 ft - maximum width of post in soil
Aftg= 3.14 ft2 - area of footing
d= - ft - depth of footing to be determined below
Per Sections 4.2.2.1 and 4.2.2.2, allowable lateral soil bearing capacities may be increased
by 2 for isolated posts (spaced at least 3 ft. apart), and by 1.33 for wind loading
SLAT= 320 psf-factored lateral soil bearing capacity
Minimum embedment depth required for lateral load, constrained at the top,
gravel backfill, per Section 6.5
dmin= [(4 x Mpost)/(SLAT x b)]^1/3
Allowable vertical soil bearing pressure for gravity loads
S = Sy x Aftg x (1 +(0.2 x (d-1))
SY= 1500 psf-vertical soil bearing capacity
Aftg= 3.14 ft2-area of footing
d= minimum depth for vertical bearing requirements
dmin_L= 2.40 ft.-minimum depth requried for
lateral load
Maximum vertical load on footing from gravity load Pfooting= 4,704 Ibs-vertical load on footing
Posthole depth for this building = 4.00 ft-minimum depth to bottom of footing
Vertical capacity for footing Paiiow= 7,540 Ibs - > Rooting - OK
Page 8 of 12
Roof and Gable Wall Shear Loads and Diaphragm Design
Roof
Roof width= 24 ft.
Hroof= 4.17 ft.
Total roof wind pres., 0.6 x Pr= -2.45 psf (0.6 x Pr)
Total roof wind pressure to use= 4.80 psf - use 0 if Pr < 0
Total wall wind pressure= 10.30 psf (0.6 x (q,, - q,r))
Total wall wind pressure to use= 10.30 psf - use 0.6 x 16 = 9.6 psf minimum
Diaphragm seismic load= 272 Ibs-(Vroof/2) x 0.7
Diaphragm wind load= 687 Ibs
Diaphragm load to use= 687 Ibs - Wind load controls
Roof shear= 29 plf
Sheathing= 29 ga. Metal only
Allowable shear= 113 plf > Roof shear - OK
Sheathing fastening= #9 screws at 9" o.c.
Gable walls
Left Gable Wall
Left gable wall shear Vseismlo= 358 Ibs-VLGW x 0.7
Left gable wall shear VW;r,d= 687 Ibs-from Diaphragm wind load above
Diaphragm load to use= 687 Ibs-Wind controls
Left Gable wall= 98 plf
Allowable shear= 113 plf > Wall shear - OK
Sheathing fastening= #9 screws at 9" o.c.
Net shear panel uplift= 765 Ibs Uplift resistance= 2,495 Ibs - >
Backfill posthole with concrete or install uplift cleats
Right Gable Wall
Right gable wall shear Vseismlc= Ibs-VRGW x 0.7
Right gable wall shear VW;r,d=It]
Ibs-from diaphragm wind load above
Diaphragm load to use=Ibs-Wind controls
Right Gable wall= 98 plf
Allowable shear= 113 plf > Wall shear - OK
Sheathing fastening= #9 screws at 9" o.c.
Net shear panel uplift= 765 Ibs Uplift resistance= 2,495 Ibs - >
Backfill posthole with concrete or install uplift cleats
765 Ibs - OK
765 Ibs - OK
Page 9 of 12
Eave Wall Shear Loads and Diaphragm Design
Eave walls
Building Length=
24
ft.
Gable wall wind pressure=
9.60
psf - use 0.6 x 16 = 9.6 psf minimum
Diaphragm wind load=
524
Ibs
Front Eave Wall
Front eave wall shear Vseismic=
399
Ibs-VFEW x 0.7
Front eave wall shear VWind=
524
Ibs-from diaphragm wind load above
Diaphragm load to use=
524
Ibs-Wind controls
Front eave wall=
22
plf
Allowable shear=
113
plf > Wall shear - OK
Sheathing fastening=
#9 screws at 9" o.c.
Rear Eave Wall
Rear eave wall shear Vseismic=
399
Ibs-VREW x 0.7
Rear eave wall shear VWind=
524
Ibs-from diaphragm wind load above
Diaphragm load to use=
524
Ibs-Wind controls
Rear eave wall=
28
Allowable shear=
113
plf > Wall shear - OK
Sheathing fastening=
#9 screws at 9" o.c.
Page 10 of 12
Purlin & Girt Calculations
Purlin Calculation
Roof Pitch:
4
Roof Angle:
18.4
Greatest purlin span:
138
Purlin SX:
7.56
Live + dead load:
28
Max. o.c. spacing:
24
M:
10,539
fb:
1,394
Fb allowable:
1,547
/12
in
in
psf
in. o.c.
in-Ibf
psi
psi -per NDS Section 4 and Design Values for Wood Construction
Purlin usage: 90% OK
End reactions:
Snow load: 322 Ibs If joist hanging, use LU26 joist hanger w/ 10d nails
or JB26 top -flange joist hanger w/ 10d nails
uplift: 266 Ibs (3) nails each side of flat purlin block
Girt Calculation
Greatest Bay Spacing:
12
ft.
O.C. Spacing:
24
in
Girt SX:
2.06
in
Total wind pressure:
12.57
psf
w:
2.09
pli
Girt Span:
138
in
M:
4,987
Ibf-in
fb:
2,421
psi
Fb allowable:
2,476
psi -per NDS Section 4 and Design Values for Wood Construction
Girt usage: 98% OK
Page 11 of 12
Bearinq Block Screws In Single Shear
Calculate required number of 5/16"0 x 3-5/8" long Fastenal Ledgerlok screws for each bearing block
Posts are assumed to be #2 HF; bearing blocks assumed to be #2 HE
Capacity for Ledgerlok Screws
Unfactored fastener capacity= 260 Ibs
Factored Ledgerlok Capacity= 300 Ibs-including all allowable increases per 2012 NDS
Intermediate truss bearing blocks
Max Truss Load= 2,352 Ibs each truss heel, each side of post
No. of screws per block= 7.8
Bearing bock
Use 2x6 bearing block
Use 10 Ledgerlock fasteners in each bearing block
under each truss heel (rounded up to next even quantity
and add (2) screws)
Page 12 of 12