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View Full Version : 1/2 in roof decking under concrete flat tile



Jerome W. Young
09-02-2008, 05:49 PM
no clips were used , joists are 24 O.C. and 32/16 thickness. I thought it had to be 5/8 for tile roofs?

Vern Heiler
09-02-2008, 06:02 PM
The 32/16 is not the thickness of the plywood sheathing, it is the span allowed. 32" roofing and 16" flooring.

Jerry Peck
09-02-2008, 06:43 PM
There would have been another label giving its thickness, such as 15/32" (1/2"), 19/32" (5/8").

Based on the span rating of 32/16, that would be 15/32" (1/2") plywood (taken from Table R503.2.1.1(1).

Typically, you will find plywood with a span rating of 40/20, which would be 19/32" (5/8").

In the HVHZ (Miami-Dade and Broward counties) the minimum if 5/8" for roof sheathing.

The Florida Manual for installing roof tiles shows (under System II) "DIVISION 7 These guidelines cover Flat/Low, Medium and High Profile Roof Tile, using a minimum 3” tile headlap, or a designed limited headlap, on minimum 15/32” solid decking nailed in compliance with wind load requirements.", on page 24.

Jerome W. Young
09-02-2008, 06:58 PM
yup, my bad on that one. It WAS HOT AS HELL IN THERE! I saw 32/16 and thought 15/32 or 1/2 . Either way it appears that it is ok.