AskCodeMan

Hi Jerry,
When did the requirement to mechanically attach hip and ridge tile take effect, are there any exceptions and where in the FBC is it located? Also in reference to repairs should this requirement be followed for roofs being repaired that were installed prior to this requirement?

That came in with the 2004 FBC: (bold and underlining are mine)
- 1507.3.6 Fasteners.
- - Tile fasteners shall be corrosion resistant and not less than 11 gage, 5/16-inch (8.0 mm) head, and of sufficient length to penetrate the deck a minimum of 0.75 inch (19.1 mm) or through the thickness of the deck, whichever is less. Attaching wire for clay or concrete tile shall not be smaller than 0.083 inch (2.1 mm). Perimeter fastening areas include three tile courses but not less than 36 inches (914 mm) from either side of hips or ridges and edges of eaves and gable rakes.

That 36 inches to either side of the hips or ridges was measured from the center line of the hips and ridges, which meant that the hips and ridges had to be attached too.

If not more than 25% of a roof is being repaired, then the roof is required to be repaired in accordance with the installation instructions/product approval for the tile installed (most used the FRSA/RTI Installation Manual).

If more than 25% of a roof or roof section is being repaired or replaced, then the entire roof is to be brought to current code:
- From the 2010 FBC-Existing Building
- - 611.1.1
- - - Not more than 25 percent of the total roof area or roof section of any existing building or structure shall be repaired, replaced or recovered in any 12 month period unless the entire roofing system or roof section conforms to requirements of this code.

The "roof or roof section" is interpreted by most AHJ to be, for one example, a gable roof and one side is being worked on, if more than 25% of that one roof section (roof face in this case) is repair or replaced then that entire roof section needs to be brought to current code, which may - or may not - require replacement of that entire roof section ... depends on how and when it was installed and if that method meets the current code or not.