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Structural Engineering, Design -& Testing, CA#28948, NOA#13-0222.02
6915 Washington Rd,W Palm Beach, FL 33405/Ph. (561)804-9908/Fax(561)804-9907/e-mail:turginc@aol.com
October 12, 2016
TO: St Lucie County/ Building Department
FROM: Riza N. ALTAN, P.E.
SUBJECT: Wind Uplift & Flat.Re-Roofing Specifications
ADDRESS: YANCY Residence / '3236 West Lake Dr., Ft Pierce, FL 34982
CONTRACTOR:Larry Neese LLC,. Roofing &Waterproofing
Dear Sir;
The re-roofing specifications for.flat areas of the subject residence have been reviewed
by myself. The purpose of this letter is to determine the wind uplift pressures and
specify attachment of self-adhered base sheet.
The existing -43'x49'x14' L-shaped flat roof is located in Exposure C area at mean roof
height of 15 ft. The, roof consists.of 19/32" CDX plywood deck, having positive drainage.
Roof design pressures; as per 2014 Florida Building Code, ASCE 7-10, 160 MPH ultimate
Wind Velocity for Risk Category II in Exposure C area, using Wind Load Factor of 0.6 for
ASD; are determined as follows:
Field Pi = -44 psf / Perimeter (4' wide) P2= -74 psf / Corner (4'x4') P3= -111 psf.
The proposed Polyglass Self-Adhered Bitumen Roof System over Wood Decks
(#FL1654-R19) consists of sealed plywood seams using 4" wide Polyflex SA-V tapes
followed by rolled-pressed Polyflex SA Base base sheet and heat-welded PolyFlex G
granule cap sheet.
The max. design pressure of-135 psf (Wood Deck, Non-Insulated, Table 1G, SystType.F,
Syst#W-142, pg. 22/45) is determined to satisfy roof uplift pressures in all roof zones.
Therefore, this letter is to certify that installation of Polyglass Self-Adhered Roof System
(#FL1654-R19) with torch-applied :cap sheet over wood decks, as described above,
conforms. to 'requirements of :2014: Florida_ Building Code which specifies 160 MPH
ultimate wind velocity for Risk Category.II in Exposure C 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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Riza N. ALTAN, P'.E. 8521 ®' °° gc s�
Consulting Engine NO.38521 ~
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