Support for Chainfall.

   / Support for Chainfall. #1  

GPintheMitten

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I want to put a chainfall support in my workshop. The shop is in the leanto on my barn. The rafters are 2x12's, 24 inch on center and span 16 feet. The ceiling runs from 12' to 8'.

I'm thinking of using 1 inch (inside diameter) black pipe. I'm thinking that I would get 6', drill holes in 2 rafters and put flanges on the end to support the ends. Probably mount it in the middle of the rafters.

Does this sound like a good plan? How much weight do you think it would support? I don't know what I'll lift exactly, but I want to do this before I put drywall on the ceiling. Would it support 1000 pounds?
 
   / Support for Chainfall. #2  
No, needs more planning.
You can't just stick a piece of pipe up there and hang 1000 pounds (potentially) off it.

If 1000 pounds will be the most you expect to lift, then I would calculate for 1500 or 2000.
You need to look at load tables for your construction and the size of the members that will be used.

It's not impossible and you made the correct first step by seeking help with the design.
 
   / Support for Chainfall. #3  
I did something similar to support my boat when off the trailer, and I looked at various chainfall sellers and crane manufacturers. I had a company in Albany, NY. make some special steel bolts to hang the chain falls from, with a loop on the bottom end. In my case, I needed to be able to lift 2 tons per chainfall and I was able to do so by drilling up through the beams and putting a plate on top and bottom to spread the load.
Personally, I wouldn't try to rig up what you want to do without some solid engineering numbers, which you may be able to get from a local company, especially in Michigan. The problem you may have is 2x 12's with holes in the middle of the 12" portion don't offer a lot of strength against a load put 1/2 way through their height.
Maybe with a reinforcement plate on either side of where you put the pipe might spread the load over a larger span.
 
   / Support for Chainfall. #4  
We have 3" wide by 5" tall I-beams here at work for our chainfalls, I-beams let you use trolleys that you can attatch you chain falls to so you can move things around. A good friend of mine that I work for while off on days also done this in his farm shop. He bolted I beams to the concrete floor and set a I beam across them. This is probly over kill for your use,but you can also purchase roll around A-frame gantrys, I believe their called, for this on a concrete floor shop. They are expensive though. I would not compromise saftey for overhead lifting.Not trying to be the saftey police,just be careful. LUTT
 
   / Support for Chainfall. #5  
Sounds real risky to me. If your shop has a floor, think gantry on wheels. Move it where you want, and you can buy or make one with the proper size I beam. Don't trust any structure until it has had 125% of the rated total load on it for 1 hour. ( dead weight lift ) My 1 ton has a 8" I beam, never moved in the least bit. Even Harbor Freight has a 1 ton unit that is adjustable and fairly cheap with the trolly. Why risk it, often breaks when least expected, lots of deaths.
Chris
 
   / Support for Chainfall.
  • Thread Starter
#6  
Thanks, guys.

I'll check the load tables for the rafters.

How do I find our about the load that steel pipe of various diameters will support for a given span.

I don't really plan on lifting 1000 pounds. It was just a number.

I don't do any heavy steel fabrication. I don't want a gandry taking up space. That and I-beams and trolleys would be way more than my needs.

For instance, if I build a cab for my tractor, I may want to take it on and off. Or load / offload something from my trailer that's too heavy for me to wrestle with.
 
   / Support for Chainfall.
  • Thread Starter
#7  
Hey, I found a steel pipe span table.

http://www.alvinindustrial.com/info/info_02.htm

Looks like 1" schedule 40 will support 1200 and 1.25" schedule 40 will support 2200.

So I'm now considering 1.25". But I'll check the rafters tables. Also, it might be better to put up a 2' section and use flanges so I don't have to drill holes. Also, I could add some angle iron to distribute the weight along a longer length of the rafters.
 
   / Support for Chainfall. #8  
1st off the ceiling runs from 12' to 8' isn't high enough. The hoist and hanger is going to take up 2' +. If you think you are high enough, then get 2 2X12's bolt a 1/4 or 3/8" plate between them and run between the ones that are there now, the same as the other. At the wall where it hooks on the barn put a leg down under it and on the other end just make sure it's strong enough.
 
   / Support for Chainfall. #9  
24 OC rafters for over lifting doesnt sound right to me. Is there any reason why you can't add ONE more rafter in the middle where you want to do the over head lifting so you can split the weight difference over 3 or more rafters? Also I am wondering why you want to drill holes? you would be splitting the " height difference for weight". if you drill a hole in middle of a 2X12, it becomes a 2x6 for weight because its supported on bottom. I understand its fine to drill holes in middle for wires, pipes, but not for direct dead loads. Can't you just put the pipe on top of the rafters? Can you also sandwich 2 2X6's and 2x4 in middle to hold pipe and use that as a beam to spread the load across the rafters better then just resting on the rafters? The sandwiched boards can spread load better and you can litterally nail each rafter to that much easier and cheaper. I can imagine the cost of lumber alone wouldnt cost over $50 bucks for one extra rafter and wood beam sandwich. that is cheap IMHO for beefing up a chain fall and not worry about a thing.
 
   / Support for Chainfall.
  • Thread Starter
#10  
Good idea.

I won't drill holes. Earlier I had thought that if I drilled an 1.25" hole in two rafters and run the pipe through them to span 3 joist bays with flanges on the outer two rafters, that I would spread the load. But you're right, holes for wires are ok, but not for a heavy load point.

I found a beam load calculator online. I calculated a 500 pound live load on a No.2 2x12, 15.5' long. It was within load and pressure specs. 500 on each of two 2x12's would be 1000 pounds.

So, now my plan is build up a sister 2x12 with 3/4" plywood sandwich glued and nailed to each rafter. That will spread the load point and bolster the load area. I don't think the sisters need to span the entire 15.5' span. I think I'll make each one 8' long centered on the span.

The 1.25" schedule 40 pipe will only span one rafter bay (24"). I'll bolt through the flange and lumber with hard bolts of the diameter that will fit in the flange holes.

Then I'll limit the loads I put on it to 1000 or less. Of course, the load will not be constant. I'll use it for temporary lifting, and off-loading.

The load would then be the same as 5 guys standing in a tight formation on the roof.

Sound better?

24 OC rafters for over lifting doesnt sound right to me. Is there any reason why you can't add ONE more rafter in the middle where you want to do the over head lifting so you can split the weight difference over 3 or more rafters? Also I am wondering why you want to drill holes? you would be splitting the " height difference for weight". if you drill a hole in middle of a 2X12, it becomes a 2x6 for weight because its supported on bottom. I understand its fine to drill holes in middle for wires, pipes, but not for direct dead loads. Can't you just put the pipe on top of the rafters? Can you also sandwich 2 2X6's and 2x4 in middle to hold pipe and use that as a beam to spread the load across the rafters better then just resting on the rafters? The sandwiched boards can spread load better and you can litterally nail each rafter to that much easier and cheaper. I can imagine the cost of lumber alone wouldnt cost over $50 bucks for one extra rafter and wood beam sandwich. that is cheap IMHO for beefing up a chain fall and not worry about a thing.
 
 
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