HomeMy WebLinkAboutREVISION, plywood resheathing 10.02.20TURQUOISE Engineering, LLC
Structural Engineering, Design & Testing, CA #28948, NOA #18A114.05
901 Forest Hill Blvd., W Palm Beach, FL 33405 / Ph (561) 804-9908 / Fax (561) 804-9907 / e-mail: turginc@aol.com
September 30, 2020
TO: Saint Lucie County /Building Department
FROM: Riza N. ALTAN, P.E.
SUBJECT: Plywood Sheathing Requirement
ADDRESS: BUTLER Residence / 3251 NW Dockage Way, Palm City, FL 34990
CONTRACTOR: Code Red Roofers
Dear Sir;
It will be an acceptable practice to install new 19/32" thick CDX plywood sheathing, into
the roof truss top chords through the existing spaced nailer -strips, for the subject roofing
project where the existing roof covering will be replaced with 5V-Crimp metal panels.
The two-story high property is in wind Exposure D area. The existing roof has gable
configuration and 6/12 slope. Asper the 2017 Florida Building Code, ASCE 7=10,
164 MPH ultimate wind velocity for Risk Category II in Exposure D area, using Wind
Load Factor of 0.6 for ASD; the wind pressures are determined as follows:
Field: Pi = - 40 psf / Perimeter (4' wide): P2 = =69 psf / Corner (4'x4'): P3 = -101 psf
The new 19/32" thick CDX plywood will be fastened into the top chord of roof trusses as
follows:
Zone #1 Field /Intermediate areas: 10d ring-shanked nails @ 6" o.c.
Zone #2 4' back from all roof edges and ridges: 10d ring-shanked nails @ 4" o.c.
Zone #3 5' back from Corners: 10d ring-shanked nails @ 4" o.c.
Therefore, this letter is to certify that, with the installation of new 19/32" CDX plywood
sheathing and 5V-Crimp metal panels; the total roof loading will remain below 47 Ibs/ft2.
It is also certified that re -roofing by using 26 Ga. Extreme Metals 5V-Crimp (#FL20378.6)
metal panels, installed using Method #1 (for Field) &Method #2 (for perimeter &corners)
over 30-Ibs roof felt roof underlayment attached w/ Simplex tags, conform to requirements
of 2017 Florida Building Code which specifies 164 MPH ultimate wind speed for Risk
Category II in Exposure D area.
If you have any questions regarding this matter or I may be of further assistance, please
do not hesitate to call me. Sincerely,
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rizaN AN, P.E. #38521 : • r,46 .••°
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