HomeMy WebLinkAboutMISC LETTERTURQUOISE Engineering, LLC
Structural Engineering, Design & Testing, CA #28948, NOA #18-1114.05
901 Forest Hill Blvd., W Palm Beach, FL 33405 / Ph. (561) 804-9908 / Fax (561) 804-9907 / e-mail: turginc@aol.com
January 30, 2020
TO: St Lucie County / Building Department
FROM: Riza N. ALTAN; P.E.
SUBJECT: Wind Uplift & Flat Roofing Specifications
ADDRESS: MIDWAY RD. BAPTIST CHURCH / 1108 W Midway Rd, Ft Pierce, FL
CONTRACTOR: CodeRed Roofers j%on —0213
PERMIT: REVIEWED FOR
SCANNED BY CODE COMPLIANCE
St. Lucie County ST. LUCIE COUNTY
Dear Sir; BOCC
The flat roofing specifications of the subject Church Extension are reviewed by myself.
The purpose of this letter is to determine the wind uplift pressures and specify
attachment of base sheet.
The flat roof takes place in wind Exposure B area, at mean roof height of 15 ft. The roof
deck consists of 19/32" CDX plywood and positive drainage. Roof design pressures, as
per 2017 Florida Building Code, ASCE 7-10, 160 MPH ultimate wind velocity, Risk
Category II and Exposure B area, using Wind Load Factor of 0.6 for ASD; are
determined as follows:
Field Pt = -32 psf / Perimeter K wide) P2 = -54 psf / Corner Kx4l P3 = -80 psf.
The proposed Polyglass Modified Bitumen Roof System over Wood Decks
(#FL1654-R24, Syst.# W-183) consists of direct -deck applied roll -pressed Polyglass SBS-
SA base sheet, followed by all self -adhering Polyglass SBS-SA cap sheet.
It is determined that the max. design pressure of -90 psf (Table 11, Non -Insulated, Wood
Deck, Syst.Type F, Syst.# W-183, Limitation as per Note #8, pg. 29/65), in all roof zones,
meets and exceeds the design uplift pressure; P3 = -80 psf.
Therefore, this letter is to certify that installation of Polyglass (#FL1654-R24, System No.:
W-183), as specified above, conforms to requirements of 2017 Florida Building Code
which specifies 160 MPH wind velocity for Risk Category II in Exposure B area.
If you have any questions regarding this matter or I may be of further assistance, please
do not hesitate to call me.
Sincerely,
Riza N. A AN, P.E. #38521
Consulting Engineer