UL 2390
1 Scope
1.1 This test method provides a means of determining wind uplift coefficients (DCp’s) for asphalt shingles subjected to an air flow perpendicular to and across the shingle surface. DCp’s are calculated by measuring pressures above and below the shingle surface at the windward and leeward sides of the sealant, taking into account shingle rigidity (El). Uplift force acting on the sealant is then calculated in accordance with the provisions described in this standard based on the basic wind speeds prescribed in ASCE 7-05 (Minimum Design Loads for Buildings and Other Structures), which are also a function of building height, building exposure category and importance factor.
1.1 revised June 12, 2009
1.2 The value for shingle rigidity (El) needed to calculate wind uplift coefficients is determined by one of two methods: testing shingle rigidity in accordance with Section 3, Shingle Rigidity, or selecting a conservative value of 2.5 lbf-in2 (7.17 kN-mm2) for shingles that comply with ASTM D225-07, Standard Specification for Asphalt Shingles (Organic Felt) Surfaced with Mineral Granules, or ASTM D3462-07, Standard Specification for Asphalt Shingles Made from Glass Felt and Surfaced with Mineral Granules.
1.2 revised June 12, 2009
1.3 This test method is applicable to any asphalt shingle surfaced with mineral granules where the shingle above is affixed to the surface of the shingle below with a sealant (factory or field applied) applied in a pattern aligned parallel to the windward edge of the shingle.
1.4 This test method does not address the following: determination of the resistance-force capability of the sealant; uplift forces due to wind acting on the fasteners used to apply the shingles to roof deck; and other factors that affect loading such as those occurring at the perimeter edge or at penetrations.
1.5 This laboratory test standard and the calculations used to determine the forces on shingles are based upon wind engineering studies. ASCE 7-05, Minimum Design Loads for Buildings and Other Structures, also contains related recognized practices. The findings obtained using this standard provide the means of determining a design value. Actual field performance is affected by numerous factors, including installation practices employed, job site conditions, time of year, weather, temperature, microclimate variations and other specific circumstances.
1.5 revised June 12, 2009