any carpenters here- how much weight can a 2x6 support?

[monster man]

I need to rig up a hoist support for swapping the body off of the car onto the truck and pulling various components. I want to use the existing open rafters in my garage, but beef them up. I was thinking of adding a vertical 2x6 on both sides of the current 2x4 and sandwiching it, one at the back of the body, and one near the front, and just hoisting it off with 2 chain hoists. Will 2 2x6's and a 2x4, supported by 3 2x4 legs on both sides of the crossbars be able to support 1,000 pounds each, front and back (of the car body, for a total of 2,000)?
I don't want my garage to collapse and was hoping somebody who had a hoist installed in their rafters could pipe up.

Essentially I'm adding a support leg on either side of the car running up to support my new crossabrs, spaced 8 feet or so wide

 

[79k20350]

depends on how its built. it could prolly support the weight. what is the width of your garage? this is more of a how you build it type deal. i cant just tell you it would work. sorry i cant be any more help than that, i just dont need you dead under a car cause i said it was ok

 

[monster man]

the legs will be eight feet apart, and there will four of them (each leg made of three two by fours). So, the wieght support will be centered four feet in (each weight support beam will be 2 2x6's and one 2x4). I want to just piggyback off the current rafters to keep it up right, but add all new weight support beams and legs.

 

[CyberSniper]

I use a piece of 2x4 steel to spread the weight across 3 trusses when I pull SBCs attached to transmissions. The garage is 22' wide. It barely moves.


If you lift off a similar setup, spreading the weight across all the trusses, and then use vertical legs going down to the floor it should be alright. I'd be more worried about the lateral stability than anything though.

 

[big83chevy4x4]

my buddy built a wood hoist to pull motors and such, it was 2 2x6 nailed together for the top, 4x4 built in a upside down T with 4x4 supports to keep it plumb. we got drunk once while pulling a motor and forgot to pull the motor mount bolts out (took the nuts off but didn't take the bolts out) and lifted the entire front end of the truck up. id say it will hold it just fine.
did the same on the rear of my truck when doing the shackle flip/rear axle swap and again when we swapped the boxes (dam PO welded a gooseneck hitch to the frame and the box but didn't see it was welded to the box)

 

[bridgeguy]

Without having a better idea of what you're talking about and preferably a diagram, I can't render any final opinion. However, if you have a garage with trusses (typically has metal plates at the joints), the lower truss chords (the horizontal pieces) are not designed to take any flexural loading whatsoever. If you have a large span stick built garage (ridge pole, purlins, and rafters), then you are going to be pushing it relying on your garage to adequately support the load you are talking about.

Personally, I would build a separate frame to support the weight of the car body as you face a very real possibility of doing permanent structural damage.

A lot of people have gotten very lucky overstressing structural members but a lot of people have not been so lucky as well.

I may not know a lot about Blazers and 4WD yet, but this is definitely something I do know about and depends on a lot of factors including the age of the structure, what grade lumber you're talking about, spacing of the rafters, exact design of your frame, etc.

 

[diesel4me]

Its risky...

I agree with Bridgeguy--I've pulled a motor and tranny using a friends garage rafters,and we swapped a cab on his truck too--his garage had 2x6 rafters and collar ties--we beefed the collar tie that the hoist attached too with 2 2x4's on the vertical,and put two 4x4's under it, on each side of the truck close to the fenders..every time we used it to lift something,the garage creaked and groaned and we heard a few loud "CRACK" noises too! .we should have tied a few collar ties together with a 2x4,but we weren't thinking..

Nothing ever broke or killed us,but we always broke out in a sweat when we pulled anything with that setup!, my Pontiac 400 and TH400 tranny swinging around on the hoist punched a nice long gash in the sheetrock and nearly took my arm off!,when it suddenly came free of the mounts and the rubber fuel line I forgot to remove finally let go--then his wife came out and told us the plaster in the parlor ceiling had a huge crack in it!

Thats when we decided to build a heavy duty swingset looking thing out of 4x4's with 2 2x12's bolted together for the overhead beam,and did that kind of work outside..it was way too cramped in the garage anyway,especially with those 4x4 posts right next to the fenders...made it 12' wide so we could walk around it ...I'd say build something like that,or rent something similar to do the job,rather than risk damage to your house! (Insurance probably wont cover damage YOU did yourself! )..

Got any friends with a backhoe or bucket loader??

Make sure you build one high enough if you do!--we forgot about the space a chain falls takes up,and we could barely lift a cab high enough to get it off a stock non lifted truck!..we wished it was at least 2 feet higher,like 12 feet instead of 10!..but they get tippier as they get taller,dont go too far overboard..

I saw one "A" frame swingset thing that had a 3" pipe for the legs and the overhead beam,that rotated on huge pillow block bearings a guy built..he used an old wagon wheel on one end of the pipe,so he could roll the 3/8"chain that was welded to the center of the pipe up and lift things by hand--he could pull a car off the frame alone quite easily with it--
He just turns the wheel until its as high as he wants it,then puts a chain with a hook on it on one of the wheel's spokes to hold it there-(lots of leverage using a big wheel VS the small pipe diameter the chain is winding up on!)-the other end of the chain to the spokes was welded to one of the legs on the "A" frame..he said his grandfather made a similar one in the 30's to use on the farm to lift and butcher hogs and cows !..it worked slick!.. I almost copied his idea for my crane,but I used a boat winch instead..

 

[poinzey]

Back when i was framing, the rule of thumb we used was basically 200# for every 2" of wood. IE a 2x4 standing vertical only count on it holding 400#s. This is not very precise but always served us well. Maybe an architect or engineer could chime in with more technical specs.

For your ceiling joists I would sandwich them with 2 2x8's and stagger your nails every 6'. Add couple of cross braces in the center where the hoist and legs will attach and you should be good to go.

 

[71RestoRod]

... or support it from the bottom

Don't know if this would work in your situation, but this is how I did my frame off...

I strapped some 4"x4" posts to my rafters, tacked some cross bracing to them to stiffen it up, and then used two 2"x10"s as the joists to hold up the body. I drilled a couple of sets of holes in each of the posts for the joists so I could use the cherry picker to raise / ratchet up the body. I lifted the front a foot or so, then the back, then the front again...

worked great and really got the body well off of the frame.

 

[bridgeguy]

Maybe an architect or engineer could chime in with more technical specs.

I did. And architects just make things pretty. Engineers make them work. (Not that I have any strong feelings about that.)

That's why I wouldn't try what he's talking about. The opportunity for a catastrophic failure is very real when you talk about suspending that much weight from a structural system that was never intended to work in that manner.

Poinzey, I've heard contractors use that "rule of thumb" before and it can be true, but in this situation, I would be hesitant to arbitrarily use 2x8 and have them be sufficient. It will depend on a lot of issues. I would definitely not nail 6' o.c. At the minimum I would use 16d @ 6" o.c. staggered, full length. The shear flow through this connection will rip right through much wider spacing.

The setup that 71restorod has is more appropriate as it does not rely on the rafters to do anything other than hold the 4x4 vertical. The only thing I would prefer to see (from what I can see in the photo) is some members across the top of the hardtop between the 4x4 running the same direction as the rafters. This would take any lateral loading off of the rafters. Otherwise, that's a really nice setup (assuming that the connections are sufficient for the loads *lil disclaimer*).

Also, that's a NICE ride you're working on. Now I'm all jealous and wishing I had a bigger garage!!

 

[monster man]

thanks guys, I think I'll go with plan B, and that's build a separate frame inside the garage, and not tie to the rafters. At this point it will probably be wood, as you all know about steel prices. I'll go price some wood, maybe just end up renting an a-frame we'll see. Thanks for the insight

 

[Desert Rat]

As was already said, for the price of the wood you can rent a cherry picker or another hoist. I found a cherry picker for a good price at Costco and just bought it. It has come in handy for many many projects and was worth the cost. I find I'm using it all the time just to lift one end of the rig up to work on an axle.

 

[poinzey]

Poinzey, I've heard contractors use that "rule of thumb" before and it can be true, but in this situation, I would be hesitant to arbitrarily use 2x8 and have them be sufficient. It will depend on a lot of issues. I would definitely not nail 6' o.c. At the minimum I would use 16d @ 6" o.c. staggered, full length. The shear flow through this connection will rip right through much wider spacing.

Thanks for clearing that up Bridgeguy. I had the idea in my head but have a hard time putting it into words sometime. And yea, the 6' was just a typo. I should have done a quick drawing. I was thinking more along the lines of what 72resto did, except also sandwich the rafters, and have the rafters sitting right on top of the 4x4's, that would help temendously with the connection there.