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Storage Space - need ideas for Mezzanine construction

motion guru

Diamond
Joined
Dec 8, 2003
Location
Yacolt, WA
We have a growing amount of surplus "STUFF" - servo motors, gear boxes, CNC controls, scales, timing belts, pulleys, bearings, etc. Right now this is taking up shop floor space. We are planning on re-arranging our shop to make loading / unloading machines from trucks easier and in this shop shuffle, I want to put up some storage space and get the surplus stuff up away from the general shop area.

I have a space that is 63 feet long by 10-1/2 feet wide (could go as far as 12 feet without infringing on crane hook area).

One side of the Mezzanine could be supported by our oversize crane runway beams. These are 27-102 beams and even with a 200 lb/sq ft load over the entire mezzanine floor (130,000 lbs) - deflection calcs indicate that the crane can still happily run along with full load and not exceed crane handbook deflections.

2013-02-06_15-18-22_387.jpg


The mezzanine height would be below the Gray Line and above the Blue line - support along the wall will be straight forward enough - steel columns and beam sections.

The question I have is how to support the beams between the crane runway support columns? The largest span is 33feet 8 inches. Is there any reason that I could not make up some cables (~ 6 feet long) and install a few tie points between the crane runway and the mezzanine support beam?

What about the actual decking? TJI's with 1" plywood? (or if I go with grating and cross beams, can I avoid having to mess with the fire sprinklers?)

I will be moving a 100 ton press, coldsaw, surface grinder and bandsaw under the covered area. . . so will put task lighting under the mezzanine for those machines.

2013-02-06_15-18-50_460.jpg
 
Not being there to actually see it, just a couple of thoughts. I think I'd use threaded rods for the suspension, easy to adjust to a close tolerance and not so subject to stretch as the cables. Most of us have seen the thinned, elongated sections in cables that can happen much easier than that sort of stretch on rods.

You probably already know this but the suspended beam, (assuming steel) can be capped with wood and the TJI hangers nailed to it or the hangers can be welded directly to the beam by a certified welder. In either case, joists and beam share the same horizontal plane, keeping the section thin.

I'm pretty certain that the fire marshal will not allow squirting the spray through grating. He has no way to be assured that "stuff" won't be set on this mezzanine, blocking the spray. Won't be worth much if you can't store stuff on top of it.

Glad to see you prospering!

Bob
 
I gotta go with prefab and sprinklers on this one...it's just not worth the pain of having you COP pulled.
Plus it's not terribly expensive and safer.

Gotta have a place for the automation lint, it sure builds up.
 
MG:

I'd suggest welding or bolting a clip angle to the crane-beam columns as a seat for the mezzanine beams. It'll be simpler than fooling with the crane beams. In either case, the column capacity will need to be checked. Check out the link to Unistrut:http://www.unistrut.us/index.php?WP=S13_Grate[/URL]. They make a grating product that can span between the framing you install along the wall and the crane beam column line. The product will handle uniform loads up to around 200 lb/ sq ft and concentrated loads of around 500lbs. Many other companies make these grating products as well. I'd recommend staying away from wood or combustible products into your building. The code and insurance folks will be a lot friendlier. As R. Campbell noted above, you'll probably have to add a few sprinkler heads.

Regards
DB
 
I don't know if the crane rail would be in the way. But what about putting in pallet racking instead of a mezzanine. You can put all your STUFF in crates or large triwall cardboard boxes, that you can either label or keep an inventory for. If you need a servo motor you pull the servo motor crate down with your forklift pick the one you need and throw the crate back on the shelf.
 
DB - We checked column loading and it is fine even if we treat as simply supported. These columns are bolted flange top and bottom and runway beams braced in both planes, as such columns are restrained and have a better than 5:1 factor of safety for buckling. This would improve further with another beam attached 6 ft down from the runway flanges.

I need the open span of 33+ feet and I am running a 5 ton crane on a 20 ton runway setup . . . Seems a waste to not take advantage of the structure that is there.

We put the crane up ourselves a couple of years ago and it passed certification with flying colors. I'll give the crane inspector that certified the crane a call and see what he says about supporting a mezzanine beam six feet below with tension rods.

The area will have the same shelving units as are presently being used on the floor. Total weight is not anticipated to be more than 20000 lbs plus the weight of the mezzanine itself. We will be nowhere near 130k lbs that the structure can support as designed.

I like the look of the grating in that craigslist ad . . . although a little more than I wanted to spend.
 
Wait a minute here.....the guru of motion wants a plain 'ol vanilla mezzanine ?

An automated stacker would be more appropriate.....
 
I think its to narrow of a space for an effective mezzanine. I would put floor to ceiling 24" deep heavy duty teardrop racking. You can leave out spots to put the back of a machine into the space.
With racking you are one veawable layer deep
With a mezzanine stuff the size or servos is fast going to be a layered digfest any time you want something in or out. Plug and play no engineering required, that and a roller set of steps and your storing in tall cotton .
 
Maybe not practical where you are, but on the East Coast I have passed up so many extremely nice all metal mezannines at auctions over the years that sold for almost nothing it makes me cringe now that I need one as well.

The biggest "didn't buy it" cringer of all was the nicest overhead gantry crane system ever (for a small to mid size shop anyway)....like brand new with two seperate 5 ton hooks that sold for something like $3,000 !!!! The funny part is the guy who bought it, took it down (side tracks were probably 100 feet long at least) and then a month or two later ended up buying the building and putting it back !!!

Anyhoo, the point is, if you can wait, you might be able to buy a ready made bolt together mezannine (i.e. like C&H sells) for peanuts at an auction.
 
I like the look of the grating in that craigslist ad . . . although a little more than I wanted to spend.
I would not count out the system id the craigslist add to quickly. I would bet that in this economy there are not alot of customers lined up. How many customers are out there for the whole systm. the alternative is to break it up and sell a coupla cabinets here and there which i s not at all attractiv time and money wise. I would think that price has a lot of room for movement. maybe even as much as half
 
Back to the "hang it off the crane beam" part for a moment. Two issues I see here, provided the crane beam has sufficient extra capacity, are the need to have a certified welder do a lot of awkward position welding, and the potential eccentric loading on the beam. Neither is insurmountable, I know, but there has to be an easier way.

Back in another lifetime, I worked for an outfit that hung lots of stuff from bridge steel, mostly "drip pans", roofs over pedestrian walkways. I tried to find an illustration of the sort of beam clamp our forge shop made, and come close to drawing a blank. Here's the closest I found:

beamclamp.jpg

The ones we used were made from 1/2" or 5/8" plate, maybe 4" wide, and did not have the lower 90 deg. bends; we hung the hangers from the 3/4" bolt that drew the halves of the camp together. We needed round rod with threads at the end, so used rods with forged eyes at the top, but the hangers could simply be bar stock with a hole for the bolt. When these are tightened they tend to draw upward until the bends come up against the beam, which could be advantageous if the hole in the hanger were positioned to draw the square cut end of the hanger up tight to the bottom of the crane beam.

These are easy to install and place the load on the beam center line. With enough hangers in each span, the hangers could become the uprights for the handrail.

Dennis
 
I don't understand all the complicated hanging ideas...why wouldn't you just bolt some lam beams or a double 2x12 to the columns out side the crane upright beams, put a few 3" steel tube posts in underneath where needed, then attach a wall plate to the long wall with the gray line and run 2 x 10 or 2 x 12 floor joists on 16" centers between the lam beam and the wall plate. Use joist hangers or rest the joists on top of the wall plates and beams. If heavy loads then put some posts under the wall plate too. Sheath the deck with 3/4" plywood and put up a railing running down the crane rail side...throw a couple cheap staircases in wherever you want and you are done.

Lots of shelf space down the wall

Am I missing something? This looks to be a simple stick frame project...
 
I don't understand all the hanging ideas...why wouldn't you just bolt some lam beams or a double 2x12 to the gantry columns, put a few 3" steel tube posts in underneath if needed, then attach a wall plate to the long wall with the gray line and run floor joists between the lam beam and the wall plate. Use joist hangers. Sheath the deck with 3/4" plywood and put up a railing running down the crane rail side...throw a couple cheap staircases in wherever you want and you are done.

Lots of shelf space down the wall

Am I missing something?

John, those were my initial thoughts, but putting a little time into calculating loads and stresses **** with a 33+ foot clear span between columns **** and you quickly realize that it is an unworkable solution taking that approach.

Getting a forklift into pallet racking with adjacent machines would be an invitation for safety problems.

I am going to talk to the crane company today and look at some beam hanger designs. I have admired a lot of new construction at airports and museums that use this design approach . . . more to come.
 
I think its to narrow of a space for an effective mezzanine. I would put floor to ceiling 24" deep heavy duty teardrop racking. You can leave out spots to put the back of a machine into the space.
With racking you are one veawable layer deep
With a mezzanine stuff the size or servos is fast going to be a layered digfest any time you want something in or out. Plug and play no engineering required, that and a roller set of steps and your storing in tall cotton .
Could you elaborate on "teardrop racking?" I'm trying to imagine how 24" deep racking, going 20' or so high, can be a substitute for a mezzanine 144" (12') deep and 144" tall, with "one viewable layer deep" shelving, say coming out 9' from the wall, leaving a 3' walkway for the entire length, or shorter, while accommodating a section that is loaded with a forklift and arranged with a pallet jack.

Somehow I can't imagine "servo" consumption at the rate that would justify a "CNC" picker system either.;)

I understand that you need the floor clear, free of any support system but I just can't keep from thinking how a sturdy group of shelving, coming 12' out from the back wall, aisles between, spreads any load above so perfectly. Say 30" aisles, another 30" for say back to back 15" deep shelves + posts = 65" joist spans.

2X6 DF joists would be hellatiously strong @ 16" O.C. and 5'5'" spans. Great mezzanine just by covering floor level shelving groups with 2X6 and 3/4" ply. Something to be said for just walking over to a shelf with servos, rather than climbing up on a mezzanine but you're not giving up that mezzanine, it is as big as the floor level shelving allocation(s) and no "cables" to jamb into with a forklift.

You mention just 4 machines that you need to place under a mezzanine where, "the largest span is 33 feet 8 inches" leading me to believe there may be additional "smaller" spans? Just how much floor space are those 4 machines going to demand?:)

Low tech Bob
PS, since you Northwest guys grow Douglas fir and make plywood, it's cheaper than it is in say Chicago.....
Edit: pallet jack on mezzanine would benefit from 1-1/4" plywood. Really heavy loads, joists @ 12" O.C. One or two forklift access points and pallet jack would limit forklift/machine "interferance".
 

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Teardrop racking/shelving is referring to the shape of the holes that are on the uprights that the cross beams drop into. The premise described was smallish motor storage well suited for access not requiring a forklift.
The fact it is called pallet racking doesn't mean you have to use pallets. My thought was just that, another thought for storage. My bad for straying from the project as planned.
 
This looks like a single supplier for what I am thinking . . . Clevises, Washers, Turnbuckles, Rod Ends, Threaded Rods: Cleveland City Forge I have one 33 foot span and one 30 foot span - six threaded rods rated at 7500 lbs each should be plenty.

After subtracting for the compressor room and the area that will be under the staircase, I have about 40 feet along the wall for machines - the cold saw will take up to 15 feet of that space, press will be another 8 feet with tooling cabinet, grinder will be 6 feet - and bandsaw located here as well. . . probably room for a cabinet for crane rigging as well.
 
a question and comment

how close to the crane power strips can you place anything that someone may "climb" on and possibly touch the strips and/or will the fork truck have the capabilty of going high enough to touch same?

Grates over top of a machine can be an issue with things that fall thru at unexpected moments.
I have a small lathe under grating and was surpised one night when a 3/8 nut that must have been sitting waiting for me, decided to scare the crap out of me when it jumped on a spinning chuck from above.
 
Back at the power plant, we built a 2-story stockroom by using a mezzanine that was part of the first floor's shelving - the shelving ran about 8 ft high, then the mezzanine, then another layer of shelving. Very fast, easy, and did it ever hold stock!

Check with an industrial shelving supplier - they may have something off-the-shelf that would do the job perfectly.
 








 
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