Issue: DCA10-DEC-247. The Petitioner “Mr. Timothy Graboski” is requesting clarification regarding Section 1504.3.1 of the 2007 Florida Building Code. The Petitioner provides for the following question:

Question: For the project in question and in accordance with FBC Section 1504.3 and Section 1504.3.1, is it acceptable to use a “self-adhering” cap sheet that does not have a “Structural Uplift Resistance Rating”?

Background:

Project description/Situation: The Petitioner is a State of Florida Certified Roofing Contractor who is in the process of providing quotation for a project located in Palm Beach County, wind zone of 140, exposure C, category II building, roof mean height of 32 feet, and roof slope of 5/12. The specifications require the use of an adhesive set roof tile system over a “self-adhering” cap sheet over an ASTM D226 Type II anchor sheet. While performing the calculations for the resistance required for the site, the HIP roof design requires 31.80 ft-Ibf.

In reviewing the product approval for the “Self-adhering” underlayment FL #5259, it was noted that there is not a resistance value listed or “limitation of use “for the Structural Uplift Resistance Rating (section 5.5.3 ERD report).

Also reviewing the test standards and code language for “Other Roof Systems” under section 1504.3.1,

2007 Florida Building Code, Building:

1504.3 Wind resistance of nonballasted roofs. Roof coverings installed on roofs in accordance with Section 1507 that are mechanically attached or adhered to the roof deck shall be designed to resist the design wind load pressures for cladding in Chapter 16.

1504.3.1 Other roof systems. Roof systems with built-up, modified bitumen, fully adhered or mechanically attached single-ply through fastened metal panel roof systems, and other types of membrane roof coverings shall also be tested in accordance with FM 4450, FM 4470, UL 580 or UL 1897.

1504.3.2 Metal panel roof systems. Metal panel roof systems through fastened or standing seam shall be tested in accordance with UL 580 or ASTM E 1592 or TAS 125.

Exception: Metal roofs constructed of cold-formed steel, where the roof deck acts as the roof covering and provides both weather protection and support for structural loads, shall be permitted to be designed and tested in accordance with the applicable referenced structural design standard in Section 2209.1.

1507.3 Clay and concrete tile. The installation of clay and concrete tile shall comply with the provisions of this section.

1507.3.1 Deck requirements. Concrete and clay tile shall be installed only over solid sheathing except where the roof covering is specifically designed and tested in accordance with Section 1609.5.2 to be applied over structural spaced sheathing boards.

1507.3.2 Deck slope. Clay and concrete roof tile shall be installed in accordance with the recommendations of FRSA/RTI 07320.

1507.3.3 Underlayment. Unless otherwise noted, required underlayment shall conform to: ASTM D 226, Type II; ASTM D 2626; ASTM D 1970 or ASTM D 6380 mineral-surfaced roll roofing. Underlayment shall be applied according to the tile manufacturer's installation instructions or the recommendations of the FRSA/TRI 07320.

1507.3.3.1 Slope and underlayment requirements. Refer to FRSA/TRI manual for underlayment and slope requirements for specific roof tile systems.

1507.3.3.2 High-slope roofs. Reserved.

1507.3.4 Clay tile. Clay roof tile shall comply with ASTM C 1167.

1507.3.5 Concrete tile. Concrete roof tile shall comply with ASTM C 1492.

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 or in accordance with the FRSA/TRI 07320 manual. Attaching wire for clay or concrete tile shall not be smaller than 0.083 inch (2.1 mm).

1507.3.7 Attachment. Clay and concrete roof tiles shall be fastened in accordance with Section 1609 or in accordance with FRSA/TRI 07320 Installation Manual.

1507.3.8 Application. Tile shall be applied according to the manufacturer's installation instructions or recommendations of the FRSA/TRI 07320.

1507.3.9 Flashing. At the juncture of the roof vertical surfaces, flashing and counter flashing shall be provided in accordance with the manufacturer's installation instructions or the recommendations of the FRSA/TRI 07320 Manual.

Staff recommendation:

Answer: According to Sections 1507.3.3 and 1507.3.8, the use and the application of the tile systems including the cap sheet shall be in accordance with the tile manufacturer’s installation instruction (i.e. the roof tile manufacturer’s product approval) or recommendations of the FRSA/TRI 07320.