Interpretation #6876

Approval of materials is the responsibility of the Building Official as provided in Section 104.9. It has been noted that this responsibility is first technical and then administrative. The technical aspect is a determination that the material or installation meets the intent of the building code. This is generally accomplished using product approvals, engineering analysis/reports or test data from recognized entities. In the case of a mechanically attached roof system, an additional number of fasteners may be calculated for the elevated pressure zones of the perimeters and corners. This is accomplished by increasing the number of fasteners in those areas or decreasing the row spacing between fasteners or a combination of both. However, with a fully adhered roof system, the system has been tested to its maximum resistance. Should the site uplift pressures exceed the limits to which the fully adhered system was tested, adding more adhesive to achieve greater uplift resistance is not an option. Florida statute requires roof systems to obtain a product approval. A product approval is based on testing which documents and verifies system performance. Should a product approved system be insufficient to meet the site conditions, the Building Official could reasonably require the substitution of a roof system which meets the roof uplift pressures. In the HVHZ verification of a proposed roof system accomplished through "in situ" testing in accordance with Testing Application Standard 124 would be an optional method to verify performance. In this way, field testing of the roof system in actual conditions may be utilized to show compliance.