HomeMy WebLinkAboutLetterGODWIN ENGINEERING AND DESIGN, LLC
8378 Foxtail Loop, Pensacola, FL 32526 1 (850)712-4219 1 chad(ftodwineng.com
January 2, 2020
To: St. Lucie County Building Division Ah"W
2300 Virginia Avenue 4Z Co
Ft. Pierce, FL 34982 �P l
Re: Ogden - Residential PV Roof Mount Installation
8200 Fort Walton Ave. JAN 0 8 2020
Fort Pierce, FL 34951
ST. Lucie County, Permitting
Plan Reviewer,
This letter is regarding the installation of a new roof mounted Solar PV System on the existing
residential structure at the address above. I have reviewed the attachment plan and have
determined that the roof mounted PV system is in compliance with the applicable sections of the
following Codes as amended and adopted by the jurisdiction:
2017 Florida Building Code 6t^ Edition, FBC
ASCE 7 Min. Design Loads for Buildings & Other Structures
Per 2017 FBC, the Roof Mounted PV system will be subject to the following design criteria:
Design Wind Speed(V it)-160mph 3sec gust, Exposure Category - C
The PV System consist of the modules, railing, and connection hardware. The system will add a
dead load of approximately 3 psf to the roof.
The existing roof covering is Asphalt Shingle with min. 1/2" plywood decking and 2" x 4" roof trusses
24" O.C. The roofing, decking, and roof trusses are in good condition. The existing structure will be
adequate for supporting the additional PV dead load and wind loads.
The securement method of the PV system is to be flush mounted to the asphalt shingle roof with
Everest railing and flashings/attachments. The attachments can be attached up to 48" apart and
should be staggered, where possible, to allow distribution of the design loads evenly to the
structure. The mounts shall be installed with a min. 5/16" lag screw with minimum 2-5/16" thread
length.
ST.LUCIE COUNTY
Please see attached documents and contact nOMMu have any questions.
Sincerely,
D. Chad Godwin, PE 81360
Exp.02/28/2021
BLDG:
DATE'
DATE/—/6
PLUMB:
DATE:
MECH:
DATE:
niiulu��lla/�
IV
BUILDING DESIGN PROPERTIES
BASIC WIND SPEED
ROOF PITCH
MEAN ROOF HEIGHT
ROOFSETBACK
ADJUSTMENT FACTOR FOR BUILDING
HEIGHTAND EXPOSURE
TOPIGRAPHICAL FACTOR
EXPOSURE
EFFECTIVE WIND AREA
UNIT
mph Figure 26.5-IC, page 249a
degrees
It
ft
If
Figure 30.5-1, pg 347
Figure 26.8-1, pg 252
ZONE1
ZONE2
ZONES
VARIABLE DESCRIPTION
SYMBOL
VALUE
VALUE
VALUE UNIT
REFERENCE: ASCE 7.10
NET DESIGN WIND PRESSURE (UPLIFT)
Pn„wMA
psf
Figure 30.5-1, pg 346
NET DESIGN WI ND PRESSURE (DOWN)
P-sopsf
Figure 30.5-1, pg 346
NET DESIGN WIND PRESSURE (UP)
P-.'psf
Calculation: PM,uP 1x Kux Pu.us
NET DESIGN WIND PRESSURE (DOWN)
puu, do„�psf
Calculation: PM, du.„„=1x Kex P,,,,k2
DESCRIPTION
DEAD LOAD
SNOW LOAD
DESIGN WIND LOAD
ASD DESIGN LOAD (UPLIFT )
DOWNFORCE CASE 1
DOWNFORCE CASE 2
DOWNFORCECASE3
DESCRIPTION
MODULE W IDTH
TOTAL DESIGN LOAD (UPLIFT)
TOTAL DESIGN LOAD IDOWNEORCE)
DISTRIBUTED LOAD (UPLIFT)
DISTRIBUTED LOAD (DOWNFORCE)
RAIL SPAN BETWEEN ANCHORS POINTS
POINT LOAD (UPLIFT)
POINT LOAD(DOWNFORCE)
L-FOOT CONNECTED BY LAG SCREW TO
ROOF TRUSS/RAFTER
Specific Gravity, Rafter
Min. Dia. of Lag Screw, 5/16
Pullout Value of
R of Lag screws
Thread Length
Design Pullout Value per Mount
SAFTEY FACTOR
6
SYMBOL VALUE VALUE VALUE
D
S
W
P1.nrn
Pen
Pd.nP
Pd�ir,
0
-131.29-99.37327.5621A2
N3
SYMBOL VALUE VALUE VALUE
B
P
P
w
L
R
R
G
D
W
Td
W,
SF
3.28
3.28
3.28
737.13
-66.47
-99.37
27.56
27.56
27.56
760.90
-309.01
-162.97
45.20
45.20
45.20
4
4
4
-243.61
-436.05
.651.86
180.81
180.81
180.81
0.55
0.55
0.55
0.3125
0.3125
0.3125
306.87
306.87
306.87
1
1
1
2.3125
2.3125
2.3125
709.64
709.636
709.639
2.91
1.63
1.09
4.i a, OH.w W fmJls/ (w"11M1
W ei n„Yjva,ItvL rlgll• h.>a...ds n/ R{mom
Y.wlu==m.m'ly epa✓dDA,iaY. r,h+a em6p.
pntmW pMkO,W [wyAOi^iYYmMbe.
LSbfrn+dVm{Ipn1
Gi6M musat(Bs r)
UNIT
psi
psf
psf
psf
Calculation:Pd ,= D+SQRT(0.6)W(asd)
psf
Calculation: Pd.lar=1.0D+1.05
psf
Calculation: Pd..y„=1.OD+1.DW
psf
Calculation:Poe,= I.OD+0.755+0.75W
UNIT
ft
psf
psf
pit
Calculation:. = PB/2 yP ni1r0sP-
pN
[alwlatiom w=PB/2 "k"nxS rOspe'°"
ft
Has
Celculatlon:R=PLB/2"�,,,,2„m°.„u,
His
CaIC=Iation:R = PLB/2 "iurne 0i'u ".
Table 11.2A, NDS 2005, page 68 (Southern Pine)
In
Ibs/in W=1800 33P D314
In Table L2, NDS 2005
W, = W "a of Lags "Td
Calculation: SF=WVR (Uplift)
❑m ��.. W 7v�,
tM.}s"IMN•.Fr1 ieM.1�1'M6.]d..{ .lrr
Ya'. u¢N,.e;neavltih Woti{Vw{..�..O�t".I.