How much do trusses weigh?

I'm thinking about building a machine shed. It's been 5 years of thinking so far, and progress is slow with plan development but...

How much do roof trusses weigh? Over in Stuck and Troubled we have a picture of the Rhino:



"nicknamed the 'Rhino' this handy unit consists of a 'H' tractor, a IHC loader and a cheapie 3 point jib. it can lift a rafter 25 ft. and can sling engines around the yard all day, just be sure to plan your turns well in advance as you have to give that boom plenty of lead time!"

I'm building a similar arrangement out of a modified bale spear with Westendorf mounts and a similar 3-point gin pole. When I'm done I want to be able to raise trusses with my 1086 and WL-42 loader to build the machine shed. Gin pole is a Cat I, 500lb limit.Bought new at Bomgaars the other day, looks just like the one in the picture except it's covered in green paint.

Can I lift 40-foot-long trusses with an arrangement like this? Or do I need to go shorter because of the weight?

These are only 26 ft long and are home-made; 2 x 6s with plywood gussets. Can't believe you wouldn't be able to handle 40 foot ones. My 'rig' is very similiar to yours; home-made hay forks on a John Deere loader; home-made boom pole cobbled on to the forks. I could have handled probably 3 times the weight.

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A 40' truss ain't gonna weigh near what that motor weighs.

I'm gonna guess around 350 pounds at most.

I got a 20' jib on a 856 with loader and we can carry 2-42' trusses with no problems.

We set the 42 footers on walls that were 17' in the air that was no problem to reach.

Gary

I lifted 20' 4/12 pitch 8' up with my WD-no problem. Mine were right on the edge of too heavy for me to physically lift, but not by much. 100 lbs each maybe. Greg

My prototype arrangement is sitting just behind the skidloader in this shot:


The forks are gone and I have some welding to do but this is the general idea I have.

the biggest trusses we set By Hand with two men were 34 footers. you will be fine. Trusses look big but they're only a few long 2x4s. biggest thing you need is height. you've got lifting ability.

It depends on the design of the truss, pitch, load bearing specs, moisture content, etc. When you decide on a design for your truss, the supplier should be able to give you an approximate weight, it will vary some even in the same batch.

That was a vey general question you asked. Rafter spacing from 2ft or 10 ft on center makes a big differance. Some buildings we have had 20 ft spacings, but I would assume you are talking 2 ft on center, and you will have no problems. Just carry your load low till you just have to go upwards. Most of that style loader is a trip bucket, and if you have men in the air setting the rafter, wrap a log chain around it so it can't trip. Dumping a engine on the ground is one thing, but taking time to run a man to the hospital is wasted time. A saftey hook on the rafter chain is very importand....beeeeen there an don dat before.

In the spirit of "teach a man to fish", let's work it out:

Assume truss spacing is 2' on center

Assume the ceiling "joist" and "rafters" are 2x6's
(conservative; 2x4's might work).

Assume the other truss chords are 2x4's.

"Ceiling joist" truss member is 40' long.

The two "rafters" together are about 45' (based on a 4-in-12 pitch, and assuming some overhang).

We'll assume all the other truss members together total 40 lineal feet.

So we have 85 lineal feet of 2x6 and 40 lineal feet of 2x4.

Assume Douglas fir or Southern yellow pine at a specific gravity of 0.5 giving a density of about 30 pounds per cubic foor.

Dimension of 2x6 is 1.5 by 5.5 inches; this gives 1.5 * 5.5 * 12 or 99 cubic inches per foot. This gives us a wood volume of 0.057 cubic feet per foot.

This gives us a weight per lineal foot of 1.7 pounds, which seems reasonable for a 2x6.

Similarly, our 2x4's weigh about 1 pound per foot.

1.7 pounds per foot x 85 feet = 146 pounds
1.0 pounds per foot x 40 feet = 40 pounds

Total 186 pounds per truss. We'll add another 14 pounds for the metal plates or other gussets and use a budgetary figure of 200 pounds per truss.

One note of caution is that trusses like this are very weak against forces perpendicular to the plane of the truss. They cannot even support their own weight if lifted flat, and will come apart if you try. The truss manufacturers have very specific requirements for how to attach and use lifting slings. Furthermore, because trusses are designed to bear weight only on their ends, a 40 foot long truss may require a spreader bar and two separate slings, even if otherwise handled vertically.