HomeMy WebLinkAboutREVISION,Engineer letter, Code Red BUTLER plywood resheathingTURQUOISE Engineering, LLC
Structural (Engineering, Design & Testing, CA #28948, NOA #1&01114005
901 Forest Hill Blvd., W Palm Beach, FL 33405 / Ph (561) 804-9908 / Fax (561) 804-9907 / e-mail: turginc@aol.com
TO:
FROM:
SUBJECT:
ADDRESS:
CONTRACTOR
Dear Sir;
August 31, 2020
Saint Lucie County /Building Department
Riza N. ALTAN, P.E.
Plywood Sheathing Requirement
BUTLER Residence / 3251 NW Dockage Way, Palm City, FL 34990
Code Red Roofers
It will be an acceptable practice to remove the existing spaced nailer -strips and replace
them with min. 19/32" thick CDX plywood sheathing over the existing roof trusses, 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 e - 40 psf /Perimeter (4°wide): Pz = -69 psf /Corner (4'x4'): Ps = -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: 8d ring-shanked nails @ 6" o.c.
Zone #2 4' back from all roof edges and ridges: 8d ring-shanked nails @ 4" o.c.
Zone #3 5' back from Corners: 8d 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 (#EL20378.6)
metal panels, installed using Method #1 & Method #2 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, �®a�'� � � � � ° Ja a
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Riza . ALT N, P.E. #38521'
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