Here’s a nice spreadsheet for slab on metal deck:
http://files.engineering.com/download.aspx?folder=4575da5e-f3ff-4fff-bcaa-9cda77806c94&file=DECKSLAB.xls
Personally, I would try to keep the topping to a minimum. Since it is a “real” full area load. Make sure to consider joist deflections and...
I’ve been told $7/yard by a local supplier for upping from 4 to 5 ksi . That said, I spec 3 ksi a lot and can’t remember the last time I received a mix design that qualified for under 4 ksi per ACI. Minimum average 28 day break I usually see is around 4.5 ksi.
I would go 4” wide with the ledge to allow for a 2x4 will. By the numbers, you should be able to get away with no additional reinforcement as the stirrups will take the load and distribute it through the depth of the beam, but I will typically put a “c” shaped stirrup with a #4 top and bottom of...
Koot - that makes no sense in my head but I’ll have to try it out.
Cal - I misread your response. If you search “tension chord bracing” there’s a few. The one XR250 is referring to might actually be one of mine.
https://www.eng-tips.com/viewthread.cfm?qid=433408
For the record I ended up...
I’ve also seen the threads, AISC papers, etc on the tension chord bracing issue. Someone needs to do a load test on one of these already so we can put it to rest. There’s no way that the verticals give enough out of plane stiffness to stabilize the truss, has to be through catenary action in the...
If those corner overhangs are 4 foot each way, I think you should really consider increasing the depth on the soffit. You should consider running a 3d model to check forces and deflections. The outriggers nearest to the corners don’t have adequate backspan to provide support so you need a...
I’m pretty familiar with FTAO walls but not enough to answer your questions. If anyone could it would be Terry Malone with Woodworks. He is the author of “The Analysis of Irregular Shaped Structures: Diaphragms and Shear Walls” which is state of the art in terms of calculating forces and...
Agree with jdgengineer. Weyerhaeuser only recommends this detail with a 2’ max overhang.
https://www.weyerhaeuser.com/application/files/5715/3806/1534/TJ-9001.pdf
Going continuous to the edge of the overhang with a solid joist is the best option. I’ve done similar overhangs with up to 12”...
Just out of curiosity can you point me in the direction of the “by the book reference”. I spent a few hours looking into this the other day on a 4-ply. Unless I missed something this is what I was able to find:
NDS - did not see anything related differentiating with between solid and built-up...
Yup. Seems like the only option would be to somehow create enough fixity at the ridge connection so that the top chord can span wall to wall. Probably only practical if the net uplift is really low. Maybe use a cantilevered steel column to resist the thrust forces? I kind of wonder in that...
I’ve looked at a number of older houses like this and have seen similar issues, either damage to the ridge board or buckling of a brace supporting the ridge board. As others have said, the ridge board theoretically don’t typically have a structural function. In my opinion, the reality is that...
No reason you couldn’t, from what I understand the sizes designated as “columns” are just a lower grade version of the beams. Not sure if the people building it would feel great about the steel beam on wood column thing even though it works. I’d just as soon throw a couple of pipe columns in for...
XR250, based on your responses I’m wasn’t sure if you were moving towards a deeper unshored deck or not. If so, I would consider hedging some on the manufacturer tables for their max construction spans. I had a recent project where I got pushed into spacing out the joists and the construction...
It looks like the thrust connection isn’t specified and is in addition to the web reinforcement. They reference you to the IRC tables and it’s pretty vague on if that should be to the web or the flange, although the section cut suggests it’s to the web. The reinforcement detail, in terms of...
If I understood him correctly, he was basically talking about forcing a milti-span deck in the strong axis to an adjacent member that deviates from the deck slope. I vaguely remember him saying something about sledgehammers, so your concerns about the residual tension in the fasteners is...
I spoke with the joist manufacturer and they recommended not having “hard valleys” and letting them warp the deck to the structure.
They gave me a rule of thumb on being able to fasten the deck between adjacent members with around 1 inch differential from the deck slopes over a 5 foot span.
