UL 580

UL 580, Standard for Tests for Uplift Resistance of Roof Assemblies, is a test standard developed by UL (now maintained by UL Standards & Engagement). It measures how well a complete roof assembly, including the deck, its attachment to the structure and the roof covering, resists wind uplift. It is one of the oldest wind uplift tests in North American use and is widely cited for metal roof panels.

How the test works

A sample roof assembly about 10 by 10 ft (3 by 3 m) is built into a chamber. Air pressure is applied beneath and suction above to simulate wind. Each class consists of a sequence of static pressure holds and a period of oscillating pressure. According to UL's code authority materials, static pressures are held for 5 minutes and oscillating pressures cycle at a 10-second frequency for 60 minutes.

Class	Nominal static	Oscillating range	Maximum static
15	15 psf (0.72 kPa)	11–21 psf	23 psf (1.10 kPa)
30	30 psf (1.44 kPa)	22–42 psf	45 psf (2.15 kPa)
60	60 psf (2.87 kPa)	44–83 psf	75 psf (3.59 kPa)
90	90 psf (4.31 kPa)	66–90 psf	105 psf (5.03 kPa)

Classes are cumulative. A Class 90 assembly has passed the Class 30, 60 and 90 sequences in turn without failing.

Code use

The International Building Code (Section 1504) requires that through-fastened and standing seam metal panel roof systems be tested to UL 580, and lists UL 580 among acceptable methods for membrane roofs along with UL 1897 and FM 4474. Many US product approvals, including Florida Product Approval files, cite UL 580 results.

Limits

A UL 580 class describes the tested assembly only: the specific panel, gauge, clip, fastener, spacing and deck. Changing any of these can change performance. The class is also not a design wind speed. The design uplift pressure at a given site must be calculated (for example under ASCE 7) and compared with the tested capacity, with appropriate safety factors. For pressures beyond Class 90, designers often use UL 1897, which runs to failure and reports an ultimate pressure.