HomeMy WebLinkAboutENGINEERINGTURQUOISE
Structural Engineering, Desi
6915 Washington Rd, West Palm Beach, FL 33405 / P
TO: St Lucie County / Buildir
FROM: Riza N. ALTAN, P.E.
SUBJECT: Enhanced Spacing of B;
ADDRESS: CALENDER Residence /
CONTRACTOR: Solis Roofing Contractor
PERMIT #: 1803-0712
Dear Sir:
Engineering, ti-C
n & Testing, CA #28948; NOA #13-0222.02
one (561) 804-9908 / Fax (561) 804-9907 / e-mail: turginc@aol.com
April 06, 2016
Department SCANNED
s Sheet Fastfttgl(EL@&=Roofing
310 Hickory Dr, Ft Pierce, FL 34982
Inc.
The re -roofing specifications for flat roof area of the subject residence is reviewed by myself.
The purpose of this review was to specif)i wind pressures and determine enhanced spacing
of base sheet fasteners.:
The one -story -high building is located in Exposure C area. The—42'x14' flat roof consists of
19/32" CDX plywood deck with positive drainage. The roof mean height is 18 ft. As per the
2017 Florida Building Code, ASCE 7-16, 1610 MPH ultimate wind velocity for Risk Category II in
Exposure C area, using Wind Load Factor of 0.6 for ASD; the wind pressures are determined
as follows:
Field: P1 = - 42 psf /_Perimeter (4' wide): P2 = - 68 psf / Corner (4'x4'): P3 = -102 psf
The proposed CertainTeed Modified Bitumep Roof System over Wood Decks as per (#FL16709.R4)
consists of mechanically attached GlasBase base sheet, followed by all hot -mopped one -ply
of Flintglas Ply4 sheet and FlintLastic •GM cap sheet.
The system max. design pressure of -60 psf (Table 5, Sys. E, Sys #:W-5, pg.14/14) is specified
by tin -tagging the base' sheet with 11 gad., 1114" long ring-shanked roofing nails, spaced at
8"o.c. along the 4"-wide; laps and 8"o.c., three rows staggered in field zones.
It is required that, in order to meet the actual roof pressures, the base sheet be tin -tagged to
the existing 19/32" plywood deck in the following enhanced pattern:
Zone 1: Field (Intermediate areas): @ 8"o.c., staggered three rows in mid -sheet
Zone 2: Perimeter (4' from edges): @ 7"o.c., staggered three rows in mid -sheet
Zone 3: Corner (4' from ea. side): @ 4"o.c., staggered three rows in mid -sheet
Laps: Field (4"min.): @ 8"o.c., P rimeter @ 7"o.c., Corners: @ 411o.c.
Therefore, this letter is to certify that re -nailing of existing plywood deck, installation of tie-in &
drip edge metals, CertainTeed hot -mopped (#FL16709.R4) non -insulated Roof System
conform to requirements of the 2017 Florida Building Code which specifies 160 MPH ultimate
wind speed for Risk Category II in Exposue C area.
If you have any questions regarding this matter or I may be of ftW&Rak'slstance, please do
not hesitate to call me. N. -4Zp ®,s®
Sincerely, o ' �.`CE1V'9 ®�
1"
o No.38521 0
STATE OF
3 1
Riza N. ALTAN, P.E.
Consulting Engineer ® 0 ' ZORIV ;°