712 AMBERJACK MCRS24-0014 ENGINEERING LETTERMichael S. Rezk Engineer-PE
Pro Custom Solar LLC 732-902-6224
3096B Hamilton Blvd
South Plainfield, NJ 07080
Re: Proposed Photovoltaic Solar Panel Installation
Dear Plan Reviewer:
Roof Type:
Attachment System:Wind Zone 1 Wind Zone 2 Wind Zone 3
3. Solar Modules shall be UL-1703 rated. Refer to manufacturers specifications sheets.
4. Positive drainage of the system shall be so as not to void the existing roof warranty.
6. Please refer to the attached structural calculations.
Michael S. Rezk, P.E.
FL. Lic. No. PE95844
Regarding the solar panel array installation on the above referenced project please note that an inspection was
performed by a representative of the Architect/Engineer of Record, and analysis of the existing structure was
conducted. There is adequate structural capacity for the installation of the array with the following recommendations:
ATLANTIC BEACH, FL 32233
1. The array will be installed on the existing roof. The roof framing is constructed of 2"x4" wood trusses @24" o.c.
spanning 12' 5" with a top chord length of 12' 7" with intermediate supports at 1/2 points, making the effective longest
span equals 8' with 1/2" plywood sheathing. The new array (See Site map by contractor) will add 2.63 Lb. / Sf. overall
to the roof. The existing structure is sufficient to support the new loads associated with the additional weight & wind
resistance. No additional structural support is required for the roof structure.
5. All aspects of the installation shall comply with the Florida Administrative Code, 2023 Florida Building Code -
Residential 8th Edition, ASCE-7-22, 2023 Florida Building Code – Energy Conservation, 8th Edition, 2020 National
Electric Code, All Local Governing County and Municipal Ordinances adopted by reference or enacted by law. All
components used meet the criteria of the Florida Solar Energy Center.
If you have any questions relating to this matter, please contact me at your earliest convenience. Thank you.
2. The attachment system shall be secured to the roof and shall be in strict compliance with manufacturers printed
instructions. The attachment system shall be UL 1703 approved tested. Provide water tight sealant at all penetrations.
Attachments shall follow panel rows as specified by the system manufacturer’s installation manual. The panel angle
shall match the roof slope. Reference summary table below:
min. 5/16” x 4” long stainless-steel lags with a min.
embedment of 3” into the rafters
Shingle
“UNIRAC NXT HORIZON 2-RAIL SYSTEM”
Fastener Info:
Fastener Max Spacing (in.)
48 48 48
August 12, 2024
Timothy Durbin
712 AMBERJACK LANE
Certification: I have reviewed the engineering testing reports for the racking and attachments to be used on this project
and I certify that the products are capable of supporting the code required loads and are suitable for this installation
when installed in strict compliance with the manufacturers printed instructions.
Michael S. Rezk Engineer-PE
Pro Custom Solar LLC 732-902-6224
3096B Hamilton Blvd
South Plainfield, NJ 07080
Gravity Load Calculation Criteria
Structural Design Loads per ASCE 7-22
Dead Loads = 10 psf + 2.6 psf (new solar panels) = 12.6 psf
Roof Live Load = 20 psf
Ground Snow Load/Live Load = 0 psf
Wind Load Calculation Criteria
Wind Loads per ASCE 7-22, Equation 29.4-7
Using an effective wind area of 10 SF, external pressure coefficient from Figure 30.3-A-I
Zone 1 = -25.2 psf Roof Slope = 7 degrees Roof Mean Height = 15 ft
Zone 2 = -33.8 psf Basic Wind Speed = 130 mph
Zone 3 = -45.6 psf Exposure = B
Per section 2.4.1, ASD combo = D + 0.6W:
Zone 1 = 2.6 psf + 0.6(-25.2 psf) = -12.5 psf
Zone 2 = 2.6 psf + 0.6(-33.8 psf) = -17.7 psf
Zone 3 = 2.6 psf + 0.6(-45.6 psf) = -24.8 psf
Check Attachment to Wood Truss
Use 5/16 dia. Lag screw w/ 3" embedment into 2 in. wide roof rafter
Lag Screw Spacing:Lag Screw Tributary Area:
Zone 1 = 48" o.c. max Zone 1 = (48" o.c. max)^2 / 144 = 16 SF
Zone 2 = 48" o.c. max Zone 2 = (48" o.c. max)^2 / 144 = 16 SF
Zone 3 = 48" o.c. max Zone 3 = (48" o.c. max)^2 / 144 = 16 SF
Lag Screw Forces:W = 266lb/in (Table 12.2A, 2015 NDS)
Zone 1 = 12.5 psf x 16 SF = 200 lb < W', OK Cd = 1.6 (Table 2.3.2, 2015 NDS)
Zone 2 = 17.7 psf x 16 SF = 283 lb < W', OK Ct = 1 (Table 2.3.3, 2015 NDS)
Zone 3 = 24.8 psf x 16 SF = 397 lb < W', OK W' = W x embed x Cd x Ct
W' = 266 lb/in x 3 in. x1.6 x 1 = 1276.8 lb
August 12, 2024