Yeah, I agree this is a tricky situation. A homeowner that's paying for an engineer will often expect some sort of definitive "safe" or "unsafe" conclusion. In reality, those terms aren't really meaningful, and it's all about levels of risk. An engineer that gives a definitive conclusion one...
I know a lot of folks here have voiced concerns about getting screws or nails to hold in end-grain. That's certainly something to consider, but that's more of a problem with wood screws, nails, sawn lumber, and thin lumber. That concern might have been overstated for this particular...
I agree with BA. Those connectors rarely develop member capacities, and getting any reliable capacities for the gangnail plates is usually impossible.
My standard approach for justifying new solar panels on a roof was to rely on the allowance for roof live load. Even long span trusses need at...
Hmm, interesting. The bevel washers are a little tricky because we aren't technically supposed to assume any friction between that washer and the side of the wood beam. So the lag screw bears on the bevel washer at an angle, and the LVL bears perpendicular to it's face, and then the washer...
Hi all,
Before you guys were engineers, were some of you Jurassic Park scientists?
A wall that's 18ft tall and 3.5' long is not even a shear wall. It's a cantilevered column.
I know it's hard to meet the architect's expectations, but sometimes you need to sit them down and explain to them...
Yes, there's definitely something needed--either calcs or detailing. So far you checks only get the load from member (b) into the lag screw, so you need to get it from the screw to member (a). The two ways to do that are bearing at the head of the screw, or having screw threads engage member...
So, rb1957 already touched on this a bit.
To have uniform force, you need the deformed shape of the bolt to match the shape of the side-walls of the hole so that there's flush and uniform bearing throughout, and you need enough pretension in the bolt to prevent any rotation. So essentially...
Hi Todd,
I don't have any experience designing PEMBs, but I have a good amount of experience working with them. I was almost never able to get anything in the building to calc out to my satisfaction even for the original applied loads. They're usually designed with the absolute most efficient...
Retired,
I'm confused. I keep saying I'm only concerned about the forces and detailing of the column, and your responses keep talking about designs for panels, girts and their connections. Anyway. I think we've talked it to death. Thanks a bunch for the input.
Generally that moment diagram looks pretty close based on your applied loads and restraints.
I'm not totally sure your applied load assumptions are accurate. That's going to depend a lot on what you're fastening, bolt pretension, and other stuff. I can expand on that if you'd like me to.
Yes, that's an illuminating list. The only way a building column is included in that list is if it's considered part of the exterior wall. If it's a wall, then 12.11 applies.
Retired,
I think you might not have fully read my posts. I agree, the panels and girts and all their attachments can be checked by Chapter 13 for non-structural wall elements.
My concern though, is what procedures are used to check out-of-plane bending forces on the columns, and the column...
I spent 13 years as a designer, but 2 years ago I switched over to be a plan reviewer with the city.
Based on the quality of work we receive I'd say most engineers aren't actually engineers at all. Some of these guys aren't even qualified to be called high school math students.
Yeah, I think we're on the same page. The crux of my issue is determining what actually counts as a bearing wall since that would trigger section 12.11.
The metal building resists out of plane wall forces with a system of pre-fab panels, horizontal girts and vertical columns. The wall panels...
Proyector, I am not sure that's correct. Section 12.11 of ASCE 7 applies to all structural walls. Per the ASCE 7 definition of a structural wall, that can be a bearing wall that doesn't participate in the primary lateral force resisting system.
EDB9, thanks for the reference. I'll see if I...
Thanks EDB8,
The girts and panels are definitely non-structural. If those girts attached directly to diaphragms, I don't think 12.11 would apply at all. But the girts deliver wall loads to columns and then those columns span between the foundation and roof. So the out-of-plane load path for...
If they are giving you "unfactored loads" that should mean that they're providing you with the actual values for D, L, Lr, E, W, H, etc. Then you plug those numbers into either the ASD or LRFD load combinations per the code.
Here's how I'd probably do it. I drew backspan is too short because I was lazy. =)
Running your double top plates out to the corner makes sure it's all tied back into your normal shear wall load path, but it adds depth to the overhang. You also could have top of beam equal top of double top...
I've heard many times that untreated wood can give good fire ratings. The basic idea is that the outside chars and the char protects the inner material. I've never done it, but this link seems to be a good place to start.
https://awc.org/codes-standards/publications/tr10
