Chain fall Mount on Rafters ?

[DougZim]

Adding a hard mount in my garage for a 2 ton chain fall, No I do not think it will support that much weight. I have no Idea how much it can support safely. That is what I am asking, does anyone have any idea? There are pictures in my Chain Fall Album. The garage is 24X36, with the rafters across the 24 Ft width.

The truss is made of a 2x6 main beam, with 2x4 as the webbing, all choice lumber. I installed a 2X10 beam between two trusses, at the peak. The beam is mounted with 4, pieces of angle iron, the angle iron is also configured to assist in holding all 4 members of the truss together. Please See the Album.

I think the design is sound, but would like to have a ball park number as a to not exceed weight. I have lifted 300Lbs by hanging a chain around the peak of a single truss.

I would like to lift an engine (250 V8) out of a boat and it has to go 6 ft off the ground to clear the back of the boat.

 

[bob15]

Do you have any trees around with large branches?

I'm not sure i would trust lifting an engine (6 feet to boot) out with what you have.

 

[quattro_sinko]

Trusses are funny. They are engineered to do a few things very well. There is a reason(actually two) that many Building Departments require Engineers to sign off on truss modifications.

If you have the space, build a wooden gantry above the motor you want to pull. You can look up the "strength" of framing lumber to know what it should hold . Then decide what kind of safety margin you are willing to tolerate.

Be SURE to brace the legs and top off very securely, so the gantry can not move.

 

[kd3pc]

trusses or rafters...the OP talks about both...???

I would not use either to do the task described. Just not worth the risk to discover that they don't hold. 300 lbs falling from 6 feet will hurt the boat and the human.

 

[Leaflessshadetree]

I woudn't hang anything other than the normal ceiling, insulation, lights from the bottom cord of a truss and even those I'd make sure the trusses were designed for it.

Something constructed at the peak I might be comfortable with.

BTW: If you raise the front of the boat (and trailer) the rear will come down quite a bit.

 

[Kaizen]

My 2x4 truss bottom cord supported my 250. Spreading that over three or four with a 4x4 and the chain fall hanging off that in theory should handle it. To be sure make A frame supports to the outside of the two joists. Or just get an engine hoist. I've had one at six feet when I tried taking it out with ******


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[Adk Mike]

I've had a chain fall for years in the shop. Just like what you want. You have to be smart. I'll set a snowblower on the bench with it. Works good for lighter stuff I need to pick up. Great for hanging deer.
Engines and heavy stuff I use something different like an engine hoist.

 

[Thumper68]

I actually went and looked at your album and would have no issues with lifting an engine with the setup you have made.

PS if you open each picture it has BB code at the bottom that you can copy paste right into your post so everyone can see your pics.

 

[DougZim]

Figured out how to pictures from the album here:
View media item 74661
View media item 74660
View media item 74666
View media item 74663
View media item 74662

 

[DougZim]

I think I will be safe lifting the engine, However It would be nice to know if I ever have to lift the entire boat. No don't think so its about 4000Lbs..
Thanks

 

[bad_idea]

Not an engineer, let me say that first. My assumption is the trusses will sag before catastrophic failure. I would suggest attaching a plumb bob to each side of the 2x10, about an 1/8" off of the ground. Lift the load just a little bit, and see if the plumb bobs touch the ground. If not, rock it. I would be VERY cautious of side loading in any direction.

 

[theoldwizard1]

Trusses are funny. They are engineered to do a few things very well. There is a reason(actually two) that many Building Departments require Engineers to sign off on truss modifications.

More specifically, they are designed to hold their weight, the weight of the roof decking and shingles and NOT MUCH ELSE ! (Well maybe a couple of beefy roofers !)

I would

• Double that 2x10
• Make a 4x4 post out of 2x4 and run it from underneath your doubled 2x10s down to the floor at each end of the 2x10s. It must be truly plumb !
• The post does not have to be attached to the floor (can be removed after you are done) but it needs to be secure enough that it won't kick out at either the top or bottom. Simple upward pressure on the 2x10s before loading should be adequate,

 

[matt_i]

More specifically, they are designed to hold their weight, the weight of the roof decking and shingles and NOT MUCH ELSE ! (Well maybe a couple of beefy roofers !)

I have ones designed for 25psf snow load which is 25,000 additional lbs "equally distributed" over the 1000sf of roof footprint. So there's a little extra capacity. But, I live where it snows. Yours may not be designed for that being in an area where I think it rarely snows and minimally at that.

What you have there is decent, but the other parts of the truss are just holding via the nailer plates.

The basic problem is if you pull out one of them, you crash the engine, the boat, the roof and you. Pretty expensive day.

I'd go with the gantry. It will have a load rating already that's conservative (center of span, point load) Steel is also going to give you a lot more indication of whether its ready to give up, in terms of visual deflection, if you exceed the load rating.

Others have suggested posts, which is also a good alternative idea but I think you have ~4ft of span there, just using calibrated eye on other dimensions. I would sister another 2x12 or LVL under that beam spanning a total of 8-10ft, and then go in with the posts. Use more angle iron to keep the beams' flat sides in alignment. Now you have a greater span distance that can actually be more useful. A 4-6ft span isn't going to pull many boat motors imo.

 

[DougZim]

Several good points brought up by all.

I have lifted 300 Lbs with a single truss and there was no groaning or movement. The engine (probably just the short block/oil pan) will weigh in at 700+ Lbs.

I am in Frederick Maryland, and have had over 2ft of snow on top of that building before. Also I would never lift anything, if there was a snow load on it.

Yes the trusses are on 4 ft centers.

Plumb bob to detect deflection is a go..

Taking comment on side load into consideration. Just thinking of an engine swinging on a chain. Plan on placing several diagonal cross supports in. On the two primary trusses, and the two adjacent trusses. That should keep it stable.

If I ever do want to lift the entire boat, I will place two sistered 2X12 X12Ft under the existing 2X10, and support that with two 4X6 post from the ground That is doable with out too much expense, and can be removed when not in use.

Again thanks for all the comments.
Doug

When I actually place this into service, I will post photos

 

[ezover]

I would go for it. as long as your the type that has good common sense to say nope this dose not feel right and stop.

 

[Dagny]

Keep the jerking and swinging to a minimum and that set up will hold a ton.

 

[Spareparts]

I did the same thing in my shop, made a couple on jack posts for extra support instead of building out of wood. When done just screwed them down and stored them for the next job. They were available at the lumber yard but were only 8" and I needed 11" so fabed my own off their design.

 

[Tennessee Cattleman]

If using a chain hoist is a regular event, a gantry crane might be a worthwhile investment, likely much less than a new or repaired garage.

 

[kbs2244]

I would worry more about the chain than the framing.

 

[engineer2]

I did it years ago in a 24x36 garage. Trusses were 16 OC. Spread the load over 3 trusses. In addition I used some angle iron bolted to the bottom of the truss that did the lifting. Lifted a 600 lb engine and then one end of a car body. No problems. When in doubt, measure the sag as you are lifting. If it is under half an inch, you are probably good to go.

 

[Ironcrow]

...will weigh in at 700+ Lbs.

...I am in Frederick Maryland

Maryland? What's the design snow load? 35 lb/sq ft? So, if you think you've got the hoist load spread over 20 sq ft you're good to go. Just don't hang an engine during a snow storm