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Barn Hoist for Loft

Started by Brian_Weekley, August 20, 2012, 01:34:21 PM

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Brian_Weekley

I was thinking some sort of barn hoist or trolley/chain fall system might be useful for moving things from the inside main floor up and into the loft of the shed I'm building.  Not to lift anything too terribly heavy—maybe 200-250 lbs max.  I was wondering if anyone had any suggestions for how this might be attached or if it's even advisable for this roof system.  I'm using 4x7 common rafters (45° pitch) spanning 14 feet and spaced 24" OC.

e aho laula

Jim_Rogers

Brian:
I did one of those, lift beams, in the shed we raised last January.
There is a drawing in that thread that shows the over and under collar beam with two post supporting the under collar beam.
See if that makes any sense to you.

If not then you may need to do a ridge beam and I have a method of doing it with the ridge beam.

Jim Rogers

PS: that thread that shows it is the one where we did the fit up prior to the raising.
I'll find the link if you need me to..... just let me know...
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Brian_Weekley

Thanks, Jim.

Yes, I remember that thread.  In this case, the hoist is outside of the building.  The lifting beam is not only supported by the collar tie, but also the two posts underneath it.  In addition, it's supported underneath the interior collar tie to counter the weight on the lifting beam.  In my case, I'd like to attach a hoist on the interior rafters near the loft, if possible.  When you refer to a ridge beam, are you suggesting changing the rafter design?

Here's Jim's link and relevant discussion for those interested:

https://forestryforum.com/board/index.php/topic,55412.msg801108.html#msg801108

Quote from: Jim_Rogers on March 06, 2012, 02:29:49 PM

The collar ties you see in the frame are special. First of all there is usually two. One on each gable end for the siding to nail to.
In her case she wanted a functioning beam to lift loads up the back side of the building on the rear or right hand gable end.

A drawing of this look like this:



And the frame work would look like this:



You can see to support the lifting beam there is two 4x4 posts on either side of the door. They sit on the tie beam, which is well supported and if it sags we can always put in a center support post under it from inside later on.

That supports the end collar beam for the light loads she'll be lifting with her block and tackle; up to swing into the loft deck through the small loft doorway.
This lifting beam would want to see-saw from the load. In order to hold the interior end down, I put another collar beam in, at the top of the lifting beam.
That means for this lifting beam to rotate on the gable end collar beam, it will have to raise the next rafter pair up, including the roof decking. I think the rope would break before that would happen.

Each rafter pair was screwed down to the plate with two timberlok screws on each tail down into the plate and each screw has high shear value. Equal to a 3/8" lag bolt.

I hope this has helped you to understand the roof system shown in the above pictures.

Jim Rogers

--Brian
e aho laula

Jim_Rogers

If you don't put the lifting beam above some collars then I don't know how you'll attach it to the rafters other than through bolts.

Years ago, I cut two 5 sided ridge beams for a barn in southern NH.
They wanted a flat surface on the bottom of the ridge beam for a track to attach to. Then there was a set of skates inside the square tubing track with a hook hanging down. On this hook was attached a set of chain falls so he could lift things up to the loft door and slide them into the loft using the track/skates. He had to modify the gable end for the track and chain falls to pass through the wall opening.

I'll look tomorrow and see if I have some finished pictures of the barn.

And yes, you'd have to modify the rafter to support the ridge beam.

It's not hard. The hard part is getting a ridge beam the right size and shape.

Jim Rogers

Going home now......
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Brian_Weekley

Jim,

I doubt I would change to a ridge beam just for this purpose.  Maybe I could just add a few short collar ties up high to support a beam for a hoist.  Something like this...



However, I'm concerned the tenons as drawn wouldn't have much purchase (relying only on the 1/2" housing and the pegs)?  Maybe the tenons on the bottom should be straight out for more support in the rafter?  Do you think something like this would work or is this unadvisable?
e aho laula

Rooster

BW,

Instead of building additonal framing for a track, you could copy the old-timers and put in a reclaimed hay track system... where a bracket is secured to each set of rafters to spread out the load of the track.

http://www.farmbuildingguide.org/dairybarns.html

The other idea is to hang a small dimension I-beam under the ridge from each set of rafters and use a trolley.

http://www.globalindustrial.com/p/material-handling/hoists-cranes/trolleys-manual-electric-air-powered/i-beam-trolley-1-000-pound-capacity

Good Luck,

Rooster

"We talk about creating millions of "shovel ready" jobs, for a society that doesn't really encourage anybody to pick up a shovel." 
Mike Rowe

"Old barns are a reminder of when I was young,
       and new barns are a reminder that I am not so young."
                          Rooster

Brian_Weekley

Rooster,

Bingo!  That's exactly what I was looking for.  A picture showing how track could be mounted directly to common rafters.  Excellent.

Thanks,

Brian

e aho laula

Brian_Weekley

e aho laula

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