Anyone out there got their steel calc website dues paid up?
Plans in front of me call for a glu-lam…. 6-3/4″ x 18″ 24F… with hangers on both sides supporting floor joists. Span is 22.5 feet. Floor area is 22.5′ long x 24′ wide. Plans state that design live load is 40 # PSF.
The 18″ glu-lam will hang down below the joists, and if possible I’d like to find a way to have a flush ceiling.
What’s the lowest profile steel tube that will support the same load?
Replies
I've got my AISC design manual out in the car, but it's awfully cold out there tonight. What's it worth to ya? lol
Bob
Bob, you're at what... $18/hr? Should take 10 minutes to look that up so how about $3?! I'll throw in a phony letter to Allan Edwards for you stating that you were my supervising PM on a very successful mega-development at $175K per year... you'll be living in Texas in no time, driving a jacked-up F350 Super Duty and wearing a suede brim with a Fort Worth crease.
Seriously, I know there are a couple of guys on here that might deign to answer this. Otherwise I gotta call the engineer tomorrow.
I suppose an alternative question is... what joist can I use to span 23' and not have a trampoline... say l/360.
Crap....now that you replied, I realize that you're actually only picking up half the span of 22.5'- my first assumptions were based on two spans of 22.5'. Now you're down to a W10x22, or a pair of C10x15.3's.
Alternatively, you could go with TJI 560-series 11 7/8" joists at 16" o.c.- even taking the stricter l/480 deflection criteria, they're good for a 23'-8"' span.
Don't worry about the letter to Allan- he's been gettin' far too cranky and cocky in his old age lately anyway- I dunno how my Jersey-born attitude would fit in down there....lol. Of course, if there's any openings out your way paying the $175k (plus relocation expenses), maybe you should fly me out there so we can talk (First Class tickets, of course......).
Bob
The beam span is 22.5' and it's right down the middle of a 24' wide building. I was sorta hoping to avoid TJIs because then I have to go two layers of 5/8 underneath (it's technically a garage). Plan was to use 2x10 or 2x12 DF depending on the beam depth (it's flush framed, obviously).
I hear that the real money is as a travelling PM for companies that build in foreign countries. There was an article recently (NYT?) about Americans buying/building these courtyard houses in China. Apparently Rupert Murdoch has one or wants one. Separately I've read that the Anglo guys who can make it happen are in high demand. Parlez-vouz Mandarin? Alternatively you could head for the tropics and handle villas for the jet set. I have an acquaintance who's a PM and is doing some palace in Tahiti. Apparently the hard part is getting anyone to work at all, much less at the ultra high levels the designers want. A third choice would be to pitch your own reality building show to the networks. You could line up some of the heavy hitters from the forums to come onboard as muscle.
I had the opportunity to go rebuild Kuwait when I was getting out of school after the forst Gulf War. Like an idiot, I chose to stay here to get married and start living the "American Dream", rather than going over there for something like $150k/year, all expenses paid, and tax free after a year. What an idiot I was.....lol
Bob
Well, because I like you, and because I was going out for a cigarette anyway, I grabbed the book. As I thought, they only have tables for W-shapes and C-channels- sizing a piece of tube steel would require math that I'm not up to doing tonight.
Based on what sounds like a 24' span with 22.5' of contributing load at 50 PSF (40 live plus 10 dead, you've got a load of 1,125 lb/LF on the beam, or a total load of 27 kips. 8" deep beams aren't tabled for longer than 20' and for a 10" deep beam, it's looking like a W10x39. That's a beefy piece of steel- around 975 lbs (you could place that yourself...lol).
For C-channels, you'd need a pair of C12x25's, which would weigh even more at around 1,250 lbs, and probably wouldn't fit in the floor system anyway.
Of course, these figures come with the usual Breaktime disclaimers that any structural information provide here is based on the preliminary information provided, and is not to be relied on in any way, shape or form for actual construction. For complete design information and structural member sizing, please consult a professional engineer (but you knew that already).
Bob
Disclaimer? I could print this out, photocopy someone's stamp onto it and they'd accept it at the building department here.
I was thinking tube because it's the easiest thing to pad out for joist hangers. Or maybe I get them welded on if I can get it together on the layout. The things an idiot will do for a clear-span ceiling!