Wind loads and roof edge resistance · Lesson 2 of 4

Wind loads and roof edge resistance: materials, standards and design constraints

ES-1 as a test standard, its editions and the IBC sections that call for it, the RE-1, RE-2 and RE-3 tests, what a test specimen and a failure are, the 1.73 to 1 ratio, what ES-1 does not cover, and how to read Drexel published pressures.

You will be able to: Name what ES-1 tests and what it leaves out, choose RE-2 or RE-3 by the exposed horizontal part, read a published sustained pressure with its material, gauge and cleat, and place the ES-1 and IBC editions in order.

10 min · 11 slides · 7 questions

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Slide 1 of 11

ES-1 is a test standard

ES-1-2022 gives the basic requirements for resistance testing of roof edge systems under simulated wind load, on low slope roofs it defines as 9.5 degrees (2:12) or less.

It tests edge systems; it does not design a roof or set the wind load.

It was written for built-up, single-ply and modified bitumen roofing.

Sources

ANSI/SPRI/FM 4435/ES-1-2022 Test Standard for Edge Systems Used with Low Slope Roofing Systems (approved November 21, 2022), including its commentary - SPRI (Single Ply Roofing Industry)

Videos for this lesson

What this video shows: A one-minute clip from a testing laboratory titled as an RE-3 coping test; its description names the RE-3 methodology and quotes SPRI's opinion that ES-1 testing should be performed on systems as manufactured by a given fabricator. Checked against the video's description only.

Video: ANSI/SPRI ES-1 Coping Pull Off - RE-3 Test by National ES Testing Service Tunney, on YouTube. Chosen from the video's published description.

Glossary

RE-1, RE-2 and RE-3: The three ES-1 resistance tests: RE-1 pulls the membrane at 25 degrees; RE-2 pulls outward on the face where the exposed horizontal part is 4 in or less; RE-3 loads the top and face of a coping together at 1.73 to 1.
Dependently terminated: ES-1's term for a roof where the edge system is what holds the membrane at the edge, as with ballast or a membrane secured more than 12 in from the roof edge; ES-1-2022 requires both RE-1 and RE-2 for such systems, except that RE-1 is not required where a mechanical peel stop sits within 12 in of the edge.
Failure (ES-1): Loss of securement of a component of the roof edge system, such as fastener pull-out, pull-through, collapse of a cleat, fascia or cover, or a cover disengaging from its cleat or clip.
ED-1: SPRI's design standard for low-slope perimeter edge metal, from 2019, covering items such as nailer attachment and galvanic compatibility, and leaving the wind load to the authority having jurisdiction.