Here’s my issue: there was still some bending of bolts and sill plate removal in Vilonia, and we’re not even delving into other EF5 candidates along the path that are missing. In addition, you say “needs to have” a continuous load path evidenced by anchor bolts being bent, versus that being typically preferable though not a requirement. That’s a big distinction, and if there’s recent literature or a presentation explicitly stating that evidence of a continuous load path with bent bolts are explicitly a universal requirement for EF5, then I’ll happily concede. But while LaDue said that bent bolts were a “key distinction” for the rating in Moore in his latest presentation, he did not say that explicit evidence of a continuous load path via bent bolts is a requirement for EF5 in general. Again, he even presented a potential scenario for EF5 involving a floor diaphragm in which anchor bolts aren’t in play at all. If you’re referencing the 2013 survey itself, then you have to at least know that individual surveys aren’t treated like tornadic case law, even though many would like that to be the case. The definition of where the bar should be unfortunately varies and changes depending on the year and who you are talking to.sorry if this explanation is a bit wordy, i tried my best to phrase it in a way thats somewhat understandable lol. tldr is if a home has bent bolts, it had a complete load path and is EF5. if it didnt, its EF4 (like vilonia).
to get an EF5 rating, a home needs to have a complete load path that can verify EF5 winds. straight nails often (but not always) stop a complete load path from occurring, such as in the case of vilonia. bent bolts are evidence of a complete load path, if there is no bent bolts, that means the failure occurred at the straight nailing rather than at the bolts, and no EF5 rating can be awarded. this is why a lot of EF5 homes often have toenailing rather than straight nailing, as toenailing better allows for the load the be transferred all the way down to the anchor bolts
its not the straight nailing that matters for an EF5 rating, but whether there is a complete load path. in the case of vilonia, the straight nailing prevented a complete load path from occurring, meaning there was no bent bolts, and therefor, no EF5 rating could be given. in other tornadoes, including (i assume) joplin, the straight nailing didnt stop a complete load path from occurring, and the force was still properly transferred all the way down to the bolts, bending them, even though the wall studs were straight nailed.
tornadoes can be straight nailed and rated EF5, or they can be straight nailed and rated EF4. its all about whether a complete load path occurs, its just less likely for that to happen in straight nailed homes
in terms of bolts being bent being a requirement for EF5, this is a quote from a paper on Moore 2013:
"it was decided that an EF5 rating would be assigned to homes that had the following characteristics:
1) foundation swept clean with debris strewn some distance downwind; (vilonia had this)
2) foundation (generally slab) to base-plate connections with properly spaced bolts with properly sized, fitted, and tightened washers and nuts; (vilonia mostly had this)
3) removal of a large percentage of the base plates from the foundation; (vilonia didnt have this)
4) some anchor bolts bent (vilonia didnt have this)"
in regards to the wicker st home's interior walls, im 90% sure those are cut nails and not bolts, but i could be wrong. kinda hard to tell from the image but i think i remember reading in a paper somewhere that they were cutnails
Essentially, if that standard is explicitly a requirement for EF5 at every WFO, there has to be some direct evidence and recent official documentation that this standard not only exists, but is current and universal with no exceptions.













