Wind loads and roof edge resistance
Why roof edges fail first, how ASCE 7-16 wind pressure is worked out for edge metal, what the ES-1 tests measure and leave out, how to read a published sustained pressure, and how to install, verify and specify a tested edge.
4 lessons · about 40 min · 14 diagrams · 3 videos
Version 1.0.0
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Lessons
0 of 4 complete
Lesson 1 · 9 min · 10 slides · 6 questions
Wind loads and roof edge resistance: principles and terminology
Why roof perimeters fail first, how wind pulls on a coping and a gravel stop, the vocabulary of ASCE 7-16 velocity pressure and zone coefficients, strength level versus allowable stress, and the three numbers a specifier must never confuse.
You will be able to: Define the terms of an ASCE 7 wind calculation for roof edge metal, say how wind loads a coping and a gravel stop, and tell demand, tested capacity and factor of safety apart, including who owns each.
Not startedStart →Lesson 2 · 10 min · 11 slides · 7 questions
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.
Not startedStart →Lesson 3 · 11 min · 12 slides · 7 questions
Wind loads and roof edge resistance: methods and worked application
A nine-step path from code edition to a tested edge, the effect of the ASCE 7 edition on wind speed, roof and wall zone sizes, a worked velocity pressure and corner pressures, two pressure bases side by side, and how to set demand beside a published capacity.
You will be able to: Follow the specifier's sequence from code edition to tested edge, work a velocity pressure and corner pressures with stated inputs and units, and compare demand with a published capacity without calling it a pass.
Not startedStart →Lesson 4 · 10 min · 12 slides · 6 questions
Wind loads and roof edge resistance: defects, verification and case study
How edges fail in storms and tests, why an edge must be installed as tested, the order and values in one manufacturer coping guide, appliances and gutters that disturb an edge, how to verify a tested system, and a case study of an RE-2 gravel stop specified where RE-3 applies.
You will be able to: Recognise how roof edges fail and which installation changes void a test, follow the installation order of one tested coping, verify a tested edge from its documents, and correct a specification that names the wrong test.
Not startedStart →
Practical task
Produce a wind and roof edge job packet for one low-slope building of your own choosing: record the code edition and wind inputs, work the corner and perimeter pressures with stated units, pick the ES-1 test the edge detail needs, and write what you would ask the engineer of record and the maker.
Hand in
- A decision rationale: the edge type (coping, fascia or gravel stop), the exposed horizontal part, and the ES-1 test (RE-2 or RE-3) it therefore calls for
- A marked-up section sketch showing the up and outward loads, cover, cleat, fastener and nailer
- An assumptions table with units: code edition and jurisdiction, wind speed and its source, Risk Category, exposure, mean roof height, Kzt, Ke, enclosure, pressure basis and factor, each labelled as given, looked up or assumed
- A quality checklist: the documents to request, the assembly match, corner system, nailer, appliances and gutters
- A defect analysis for one failure from the module (for example an unlatched hem or a perimeter rating used at a corner): what failed, why, and what you would change
Rubric
| Criterion | Meets the standard when |
|---|---|
| Test selection | The ES-1 test is chosen from the exposed horizontal part (RE-2 for 4 in or less, RE-3 for more) and the reason is written down. |
| Assumptions | Every input has a unit and a source, and the code edition is stated before any wind speed is used. |
| Calculation | Velocity pressure and the zone pressures are worked in order with the coefficients named, and the pressure basis and factor are shown as the engineer of record's choice. |
| Capacity | A published pressure is set beside demand as an illustration only, with its material, gauge, face height and cleat, and never called a pass. |
| Verification | The packet asks for the test report naming the exact assembly and checks installation against it. |
| Boundaries | The packet states that the engineer of record approves, gives no AFS fastener spacing of its own (a maker's published values are cited by that maker's name), and names fall protection at the roof edge. |