HomeMy WebLinkAboutLetter; Nakelski - Residential PV Roof Mount Installationf
GODWIN ENGINEERING
v.i
AND DESIGN, LLC
8378 Foxtail Loop, Pensacola, FL 32526 1 (850)712-4219 1 chad@godwineng.com
November 15, 2019
To: St. Lucie County Building Division
2300 Virginia Avenue
Ft. Pierce, FL 34982
Re: Nakelski - Residential PV Roof Mount Installation
9624 Enclave Circle
Port Saint Lucie, FL 34986
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 6th 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 Barrel tile with min. 2/2" 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 Barrel tile roof with the
Ironridge railing and flashings/attachments. The flashings/attachments are the quickmount Tile
Replacement lashings and the RT mini mounts. The attachments can be attached up to 48" apart.
The mounts should be staggered, where possible, to allow distribution of the design loads evenly to
the structure. The mounts shall be installed with 2 x M5 x 60mm stainless lag screws directly to the
roof truss.
SULICIE COUNTY
PLAN REVIEW
Please see attached documents and contact me should yvu+avearry question\\\\11I I I'I1///7yi
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Sincerely, ;
DATE:/" 7-7'� - -aD. Chad Godwin, PE 81360 PLUMB: �01' ST E t %�`
Exp. 02/28/2021 DATE: i'n .! p OF h
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BUILDING DESIGN PROPERTIES
BASIC WIND SPEED
ROOFPITCH
MEAN ROOF HEIGHT
ROOF SETBACK
ADJUSTMENT FACTOR FOR BUILDING
HEIGHT AND EXPOSURE
TOPIGRAPHICAL FACTOR
EXPOSURE
EFFECTIVE WIND AREA
SYMBOL VALUE
V T 160 -
UNIT
mph Figure 26.5-IC, page 249a
degrees
It
ft
a
sf
Figure 30.5-1, pg 347
Figure 26.8-1, pg 252
20NE1 ZONE2 ZONE3
VARIABLE DESCRIPTION SYMBOL VALUE VALUE VALUE UNIT REFERENCE: ASCE 7.10
-
20.3
20.3
20.3
-50.94
-88.81
-131.29
24.56
29.56
24.56
NET DESIGN WI N D PRESSURE (UPLIFT) P,,,,aa 42.1 73.4 -108.5 psf Figure 30.5-1, pg 346
NET DESIGN WIND PRESSURE (DOWN) Pne. psf Figure 30.5-1, pg 346
NET DESIGN WIND PRESSURE (UP) P_p psf Calculation: P,,,,,,,=2.X Kn. P,,
NET DESIGN WIND PRESSURE (DOWN) P,aa,,, psf Calculation: P-d-=1X KuX P...
DESCRIPTION
DEAD LOAD
SNOW LOAD
DESIGN WIND LOAD
DOWNFORCE CASE 1
DOWNFORCE CASE 2
DOW NFORCE ME 3
DESCRIPTION
MODULE WIDTH
TOTAL DESIGN LOAD (UPLIFT)
TOTAL DESIGN LOAD(DOWNFORCE)
DISTRIBUTED LOAD (UPLIFT)
DISTRIBUTED MAD(DOWNFORCE)
RAIL SPAN BETWEEN ANCHORS POINTS
POINTLOAD(UPLI
POINTLOAD(DOWNFORCE)
L-FOOT CONNECTED BY LAG SCREW TO
Roof Was
Specific Gravity,
Min. Dia. Of Lag Screw,1/4"
Pullout Value of
If of Lag screws
Thread Length
Design Pullout Value per Mount
SAFTEYFACTOR
SYMBOL VALUE VALUE VALUE
D
5
W
P-r,,
Pdms�
Pdn
3
3
3
0
0
0
-50.94
-88.81
-131.29
.37.13
-66.47
-99.37
3
3
3
27.56
27.56
27.56
21.42
21.42
21.42
SYMBOL VALUE VALUE VALUE
B
P
P
w
w
L
R
G
D
W
Ta
W,
SF
3.28
3.28
3.28
-37.13
-66.47
-99.37
27.56
27.56
27.56
-60.90
-109.01
-162.97
45.20
45.20
45.20
4.
4
2
-243.61
-436.05
.325.93
180.81
180.81
90.41
0.5
0.5
0.5
0.25
0.25
0.25
225
225
225
2
2
2
1.5
1.5
1.5
675
675
675
Z.77
2.55,
2.07
arr ar P.mArwrm7as(nart..N
rw]yv]rs.+rraa.a<ms m.wm
rma"umtp] n]w wd4A.Yu'. aF �.. W q..
ILLW yM`OM]r prpCwtlWu1a.]m.
Lia]ae6q<IU-1Yvri
Ina, Roof
GWMIIw1IBa7'F
UNIT
Pal
Pad
psf
psf
Calculation: P,,us,= D+SQRT(0.6)W(asd)
psf
Calculation: Pd,,,,= S.OD+I.OS
psf
Calculation: Pams,= I.OD+S.OW
psf
Calculation: Pdmc.=1.OD+OJ5S+0.75W
UNIT
It
psf
psf
pif
Calculation: w= PB/2 ""°'" "Ace"°"
pif
Calculation: w= PB/2 *--2 "'a
ft
Ibs
Calculation: R=PIB/2 •"""""'t""•ce"""
firs
Calculatlon:R = PIB/2
Table 11.2A, NOS 20G5, page 68 (Southern Pine)
In
Ibs/in W=1800G"1 DV"
In Table L2, NDS 2005
W,= W' 4 of Lags'T,
Calculation: SF=WVR (Uplift)
❑ M. io Zwa � W Zuer ■ W^n Zorn
a-aaannxaL-Fa P�.-ro .°a4]rar.
C. GD //
SF�• G i
_ 160
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