1 Ton Chain Hoist

[Rickstir]

I am thinking of getting a 1-ton chain hoist for my shop to use with the riding mower maintenance. The shop has engineered trusses on solid 4 x 6 posts, with ample blocking bolted on which the trusses sit on. My question is should I re-enforce the 2 X 6 beam the hoist will be attached to? Riding mower wieghts 568 lbs. Can't think of anything heavier that that I would try to hoist.

 

[MrJimi]

Consider this, your trusses are engineered to hold only so much weight, I would not do it.
I use a engine hoist to lift mower, attachments and lots of other things my old tired body can't and won't lift
engine hoist can be bought almost anywhere and samsclub has a nice one for less than $200
and an engine hoist is on wheels and very mobile and I have put mine in bed of my pickup for more portability
worth a look
Jim

 

[horse7]

You would need to do some analysis, and from here it is pretty hard to say too much since you neglected to indicate the garage span and spacing for the trusses, as well as your location (location would provide some insight on wind and snow loading). Building age might be important, some older out buildings are constructed to, well, lower standards.

Properly blocked 4x6 posts might have enough strength. The 2x6 bottom chord of the trusses would almost surely not be adequate by itself.

One problem you need to think about is deflection-- each time you use the hoist, you pull down on the entire roof system some. While you only expect to lift 600lb, next thing you know you want to pull a truck diesel that weighs 1000lb, then .... who knows what.

Personally, if there was enough clearance, I'd put in a separate [edit: steel "I" beam] beam and use a trolley so things could be picked and moved. Most garages won't give you enough clearance unless like mine they are designed with extra height. Also, a separate beam keeps the load off the roof system.

If you are determined to use the bottom chord, you'd need to look at spans, deflections, post strength (including foundation support strength (I suppose this is a pole building?)), shear esp at the hoist point and columns, and safety margins to figure out how much and what needs to be added for a suitable implementation. Although I suppose you would need to do most of that anyway if the beam were separate....

Or do it the good old boy way, build it and lift 4000lb and if it doesn't break then say it is strong enough for 700lb. [no this won't meet code and no one will sign off on it!]

 

[TedLaRue]

During construction of your shop it is likely that when the truss design was selected, it was the minimal design that meets code. That code would take into consideration span and wind and snow load on the roof, species of wood used, etc. It would not take into consideration a possible 1-ton downward point-load somewhere on the bottom chord of one of the trusses.

Ok, the 568 lb. mower won't be a 1-ton load, but as horse7 said, you (or someone else someday) will be tempted to push the limit.

The 4x6 posts won't fail. They can take a very large compressive force. The "ample blocking bolted on which the trusses sit on" (a ledger) or the bolted connection is more likely to fail than the posts. I don't think either of these will fail if you're only hoisting one end of a 568 lb. mower. Or even the whole mower, for that matter.

But the trusses themselves are more vulnerable. I certainly wouldn't attach a hoist to the bottom chord of a single truss. If you're determined to install the hoist, you should at least glue and nail together a couple of 12 foot long 2x6's (or better yet, 16' long 2x8's) and mount that beam (on edge, of course) perpendicular to the trusses across and above the bottom chords of the trusses. That should allow you to distribute the weight across at least 7 trusses. Make sure the way you mount the beam won't allow it to flop over on its side when under load. Furthermore, if you have the option, mount the hoist as near to a wall as you can. In any case, make sure you have the clearance to get the beam up into the trusses before you build it. It could be difficult, especially with a lot of webbing in the truss design, with a low-pitch roof, and/or with 16" truss spacing (rather than 24" spacing).

Solutions suggested by MrJimi and horse7 above (engine hoist or an independent steel I-beam) would be safer. The steel I-beam might cost big bucks depending on your span...not to mention the difficulty in getting it installed. The portability of the engine hoist is nice, but I don't know how much of an advantage that would be if all you want to do is clean the mower deck, change/replace a belt, or maybe grease your mower. To decide, you'll have to think of what possible future uses you'll have for hoisting things besides your mower.

 

[horse7]

One great convenience you might discover is that a hoist lets you get 'stuff' out of your PU bed. At the yard (or shipper, or where ever) they have forklifts, but at home, you need to unload that machinery. The load can be lifted slightly, then drive out the truck, then put the load on a trolley of some kind so it can be rolled around conveniently.

Suddenly, a higher load capacity seems useful.

A friend of mine put in a 4t bridge crane, 50' span, so he could work on his tractors and whatever else it is he does (must be nice huh?).

 

[heymack]

But the trusses themselves are more vulnerable. I certainly wouldn't attach a hoist to the bottom chord of a single truss. If you're determined to install the hoist, you should at least glue and nail together a couple of 12 foot long 2x6's (or better yet, 16' long 2x8's) and mount that beam (on edge, of course) perpendicular to the trusses across and above the bottom chords of the trusses. That should allow you to distribute the weight across at least 7 trusses. Make sure the way you mount the beam won't allow it to flop over on its side when under load. Furthermore, if you have the option, mount the hoist as near to a wall as you can. In any case, make sure you have the clearance to get the beam up into the trusses before you build it. It could be difficult, especially with a lot of webbing in the truss design, with a low-pitch roof, and/or with 16" truss spacing (rather than 24" spacing).

In my garage I installed an 8' 4x4 perpendicular to the trusses (blocked on both sides so it couldn't move), inserted an eye bolt and used my chain hoist to lift the long bed off my pick up truck when I was restoring it. I estimate that the bed probably weighs 400-500#s. At one point it hung there for several months with no problems or ill effects on the structure....not saying that you should do the same as I cannot comment on your construction, but my set-up worked very well for me.

 

[Rickstir]

Thanks everyone for the expert input. I have posed this question on two other boards and have chosen to abandon the original plan. My trusses are on 8 ft. centers. I have two options. 1) build a "swing-set" type steel apparatus with castors and 2) move outside to the porch on the end of the shop. There are whole cedar logs holding up the porch roof. There is a 2/6 on each side of the logs(poles). I will look at filling in the void in one section with 2x6's and plywood. The span will only be about 9 ft. That should give me room to work and I wouldn't be doing any work on the mower in the winter time anyways. I don't do much mechanically, so lifting one end of the mower would be about it, and there have been too many times when I needed to do this not to put something in place. I ain't getting any younger.

 

[dooleysm]

I see you've decided to abandon the plan, but as I have a similar situation to share, I'll post it in case anyone else is reading and is interested.

I've got a 32x40 pole barn (6x6 posts) with the trusses running 32'. I obtained a used chain hoist for free and decided to use it. Fortunately for me, my inlaws own a construction supply company and had designed and built my trusses for me.

I asked the architect that designed him how much they could support. He ran the numbers and claimed that each truss (2x6 bottom chord, 4/12 roof pitch) could support on the order of 350 pounds (he gave me an exact number, but I don't recall it now. He claimed the strongest point as far as down pressure would be where the webbing connects to the bottom board, about 1/3 of the way from each end.

After talking this over with him I took a 4ish' piece of leftover 6x6 and nailed that in the 'crotch' of the webbing between 2 trusses (4' centers) and hung (hanged?) my hoist off that 6x6.

I know that I can't lift my tractor or anything huge with it, but it's been very helpful all the same. I use it to lift the front end of my lawn tractor to get at the blades. I use it to hang deer when skinning. I use it to hold my PHD while I attach it to the tractor (very handy when you're by yourself). I've probably used it for other stuff I don't remember now, but those are the big things. I have a FEL, so I use that to get stuff out of my truck bed that I can't lift

Anyway, that'll give you some idea of the order of magnitude of weight that the bottom chord of a 32' truss will hold.