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HomeMy WebLinkAboutEngineering TURQUOISE Engineering, LLC 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 May 26, 2016 TO: St Lucie County/ Building Department FROM: Riza N. ALTAN, P.E. SUBJECT: Wind Uplift & Flat Re-Roofing Specifications ADDRESS: NOBEL Residence / 3204 Live Oak Ln., Ft Piere FL 34981 CONTRACTOR:Larry Neese LLC, Roofing &Waterproofing CA12�'E:_�P"V177:D JUN 0 12016 F'1=ft:£:iTTi;N4G Dear Sir; 5t. Lucie GCre.;eaFy, i L The re-roofing specifications for low-sloped 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 40'x18' flat roof is located in Exposure C area at mean roof height of 15 ft. The roof consists of 5/8" 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-R16) consists of sealed plywood seams using 4" wide Polyflex SAN tapes followed by rolled-pressed Polyflex SA Base base sheet and torched-down PolyFlex G cap sheet. The max. design pressure of-135 psf (Wood Deck, Non-Insulated, Table 1F, Syst Type F, Syst#w-53, pg. 9/36) 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-R16) with torched-down 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, n • o Riza N. ALTAN, R.E. 3852:1^ �'r -� , ,, t ;,®� 4.••�`C�NSF••••• ®� Consulting Engineer t,, <' ' ' ? No.38521 • o STATE OF o 0 ° :.off •°•• Atolvo �¢SS/0NAk- ®C-)®vim t �����aEls®eye