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Between 265 & 485 SQ/FT The 12-Gauge Garage

Workspaces sized between 265 and 485 squarefeet.

CTyankee

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Jan 13, 2013
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CT
Re: Structural Engineering: Where does this fail first?

How many beers did it take to build that? :lol_hitti
 
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Kevin54

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Jan 12, 2005
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Urbana, Ohio
Re: Structural Engineering: Where does this fail first?

You're fine as long as the rails are more towards the ends and not the center. How long are the beams?
 

Tim The Tool Man

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Mar 1, 2012
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Lehigh Valley, PA
Re: Structural Engineering: Where does this fail first?

As Strouty mentioned, scab in a 2x4 under the center 2x4. The only other thing I would change is possibly remove at least one of the diagonals and screw in a cut to size full strip of 5/8 or 3/4 plywood. Really though, as it is currently built, you ought not have any real issues and it won't tip over. Just don't stand between the two steel beams when you are unloading things and video the whole ordeal just in case!
 

MikeF2316

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Dec 29, 2012
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Thornhill, ON
Re: Structural Engineering: Where does this fail first?

That will support 1200 lbs from now 'till the wood rots. I'd bet the first failure (at higher load) would be the screws pulling out.
 

bczygan

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Nov 4, 2009
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DETROIT! Arsenal of Scrappers
Re: Structural Engineering: Where does this fail first?

Thanks, guys! This stuff is interesting, to me -- even if I've got no business doing it.

I'm moving a big box that actually weighs about 1,000 pounds. This thing I've built will function a little like a railway trestle. It will support two beams (perpendicular to its orientation) about 5-1/2' apart, which is why I wasn't all that concerned about connecting the middle upright to the ground, although that's obviously very easy to do. The primary function for that middle upright was to provide a tie-in point for the two diagonals.

I know nails are stronger, in terms of shear, but this is something I'll be taking back apart later this weekend, so I wanted to make disassembly simple.

I'll add some more screws, I guess. It'll be interesting to see if there's any deflection in the center at all with the load so close to the two supported uprights.

Get a 1lb box of 16p duplex nails at any big box store. They have double heads and are used for concrete formwork. You can pull them out after use.

Bill

Duplex-Head-Nail.jpg
 

Jeff Ivers

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Apr 9, 2010
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2,549
Location
Oklahoma
Re: Structural Engineering: Where does this fail first?

Based on the quality of the stuff you have posted on here in the past, have you already engineered this and are posting it as a test? If it were me, and I am not an engineer, I would have approached it differently. I would have a 4x4 vertical (or 2 2x4 screwed together) under each rail and use all the long lumber to keep those items vertical and spaced correctly. Best of luck with your project. It is always entertaining to check in on your creations.
 

L.Cheapo

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Oct 23, 2014
Messages
5,870
Re: Structural Engineering: Where does this fail first?

Get a 1lb box of 16p duplex nails at any big box store. They have double heads and are used for concrete formwork. You can pull them out after use.

Bill

Then pick yourself up a Hydraulic Nail Unbender so you can use them over again. :beer:

get-attachment.asp
 

CumminsFan

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Dec 27, 2009
Messages
47
Re: Structural Engineering: Where does this fail first?

Jack, Side to side, fore and aft, and vertical loads appear to be addressed to a degree. What happens if the top or bottom 2x4s roll? Your structure is going to fail catastrophically. You might consider placing some reinforcement to prevent rolling of those top and bottom members.
 

The Tool Tyrant

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Dec 19, 2011
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Bonita, Ca. (San Diego)
Re: Structural Engineering: Where does this fail first?

Is this a 'trick' question? :headscrat...Of course, it will fail wherever the failure will cause the costliest amount of damage... according to 'Murphy's Law Of Structural Design and Physics'. I thought EVERYONE knew that! :rolleyes:
 

Bring Spares Along

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Aug 24, 2013
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108
Location
Kamloops BC Canada
Re: Structural Engineering: Where does this fail first?

The knot on the top piece concerns me. That is a utility grade piece of wood. If you can find MSR lumber used in truss building it should hold up no problem.
 

EarlyBroncoGuy

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Aug 15, 2013
Messages
917
Re: Structural Engineering: Where does this fail first?

Where will it fail first?

At it's weakest point.

:lol:

Heck, I put the body of my Bronco on a rolling table I built out of 4x4 legs and 2x6 beams (all joints notched, screwed, and glued) and left it there for weeks while the frame was being blasted and powdercoated. No problem, rolled around easily.


Elgin-20150617-00091_zpsnx1twjhw.jpg
 

zmaxmotorsports

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Jan 11, 2013
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South of omaha
Re: Structural Engineering: Where does this fail first?

I'd triangulate the end pieces with some 1/2" plywood to tie them together better.
I'd also use the double headed nails.
Other than that I've done stupider things wirh far less on a pinch as long as nobody is working under it.
 

AndyCBR

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Jun 22, 2014
Messages
396
Location
Baton Rouge, LA
Re: Structural Engineering: Where does this fail first?

As others have said, the only real weak spot is the lack of cribbing to ground for the center member. Shore that up and you should be good to go.

You would be shocked at what framers build to support a full unit of OSB on a roof.
 

Burgerkong

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Apr 17, 2010
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Location
Markham, Ontario, Canada
Re: Structural Engineering: Where does this fail first?

I would've sat the top beam on some posts which would be braced laterally to the beam, then make some a-frame legs. If this is a static load, I'd also raise the stand 7" to match the wall.
 

ItsNemo

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Mar 5, 2016
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4,805
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Canada
Re: Structural Engineering: Where does this fail first?

Jack, Side to side, fore and aft, and vertical loads appear to be addressed to a degree. What happens if the top or bottom 2x4s roll? Your structure is going to fail catastrophically. You might consider placing some reinforcement to prevent rolling of those top and bottom members.
This. Biggest risk to me looks like the top/bottom 2x4's or the vertical 2x4 supports would roll.
 

PugetDude

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Mar 13, 2013
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Superstition Mountains, AZ
Re: Structural Engineering: Where does this fail first?

Put your beams on that assembly and then stack sandbags on it like they used to test airplane wings...the allowable load is one sandbag less than the one that caused it to snap. ;)
 

CGT80

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Aug 29, 2014
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IE, SoCal, USA
Re: Structural Engineering: Where does this fail first?

I'm moving a big box that actually weighs about 1,000 pounds.

I was thinking about buying a big box that weighs 2200-2400 pounds, but I would hire pros to move that. While I would like to DIY, moving heavy objects can be risky and tough, although I would be tempted at only 1000 pounds. The pros have some tricks such as teflon sheets, rollers or pipes, etc. to safely move heavy items. Hopefully, you have some of those tools as well and plenty of man power.

2x lumber can be very strong. It is great that people should not get hurt, but also consider plan B, if this contraption was to fail. Extra nails or lumber is cheap insurance and simpson brackets aren't too pricey either...........well the smaller ones. The engineers must get a kick back on the cost of those, as some of them get very expensive. A house addition, that my brother and I did the grading for, has simpson galvanized steel columns that are 6" deep to fit in the corners of 2x6 walls. Those must have cost a pretty penny, but then again the garage is a two story at 3+ cars on the upper floor and 2.5 car size below, due to the stair case between the levels. There is a bridge from the upper floor to the upper floor of the house, so you can park at street level and walk right from the garage to the bedrooms.

Good luck on your move.
 

ddawg16

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Jul 11, 2008
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21,005
Location
S. California
Re: Structural Engineering: Where does this fail first?

That will hold a lot more than 1200 lbs.

'Assuming' the load does not have any horizontal movement.
 

sberry

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Jun 18, 2005
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Brethren, Michigan
Re: Structural Engineering: Where does this fail first?

This. Biggest risk to me looks like the top/bottom 2x4's or the vertical 2x4 supports would roll.
Agree, the additional post should have a scab, like a knotch if you will or a crippled to keep it from rolling at that point.
 
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maxpower_hd

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Apr 17, 2015
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Location
Massachusetts
Re: Structural Engineering: Where does this fail first?

I'm thinking a 2x4 spacer/foot in the center under the 2x4 upright to prevent sagging. But it doesn't look like much of an issue to me.
 

theoldwizard1

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Joined
Feb 22, 2011
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43,072
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SE MI
Re: Structural Engineering: Where does this fail first?

The "generic" answer to the "generic" question, mots failures are at the joints.

That does assume that the structural elements are all equally as strong (the knot issue)
 

APEowner

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Oct 2, 2009
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Sunny, New Mexico
Re: Structural Engineering: Where does this fail first?

Jack - If you use structural screws like Spax or Timberlocks and use 2 per joint then you'll be fine.
 

Glacial_Speed

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Sep 15, 2012
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6,995
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Massachusetts
Re: Structural Engineering: Where does this fail first?

I like the idea of some structural screws for better shear strength.

As mentioned above perhaps some more bracing to address the possible rolling of the top and bottom beams.

If you're going to swap out the 2x4 for something cleaner, a 2x6 would be stronger.......probably overkill, but I'm not used to moving 1200lb things around.
 

davejo

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Oct 29, 2015
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276
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(VA)
Re: Structural Engineering: Where does this fail first?

Put your beams on that assembly and then stack sandbags on it like they used to test airplane wings...the allowable load is one sandbag less than the one that caused it to snap. ;)

Dad's first job was working on B52 wing loading. Told me the wing tips can flex up to 24 feet depending on load. I'll have to ask him if they used sand bags.

Are the beams going to be attached to this sawhorse somehow?
 
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J

Jack Olsen

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Mar 22, 2009
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Los Angeles
Re: Structural Engineering: Where does this fail first?

Thanks, guys. The support got used today and it worked fine. It was never going to be supporting the full 1,200 pounds, since the load was on a span between the support and a wall.

The purpose was for my kids' playhouse, which they agreed to donate to their school. It saved me from having to build a second playhouse for the school, but meant I had to figure out how to move an 8' tall box across town.

Here are some pictures from today. It was a one-man job, and there were no incidents.

Ready to move, but the fence had to be cut.

IN9Fii.jpg


The slope it was traveling down was less than I'd been imagining it in my head. The PVC pipes flexed more than I liked, but still worked well. I made a last-minute decision to make another support along the wall so that the spanning 4x4 could be removed more easily once I had the load square above the trailer. You can see the support along the wall was very simple -- two uprights supporting a 2x6 and a sistered in 2x4. I used two very stout 12-inch clamps to make sure the wall support couldn't move at all. I also tied the spanning members into this support with L-brackets so the 4x4's couldn't slip off as the load moved laterally.

UZKdL5.jpg


The support piece ended up off-center, I think because of the way the trailer had to fit in. But still, even if the total weight is 1,200 pounds (which I think is high), there probably isn't more than 400 pounds (probably less) where the poorly-placed corner is. I could have supported the center pillar -- but I just don't think there was enough of a load to make it necessary.

PROn99.jpg


I used straps underneath that ran through holes I drilled in the floor joists. It didn't move at all in transit -- although it was clearly a mistake to center the load on the axle. More tongue weight would have meant better handling, but this was just for a 20-minute drive across town.

yxvZo8.jpg
 

zktk01

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Dec 22, 2016
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809
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KY
Re: Structural Engineering: Where does this fail first?

Did you use screws or nails if screws I would say shear force on the ridge.
 

Daedalus

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Sep 28, 2009
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5,949
Re: Structural Engineering: Where does this fail first?

You need a friend with a truck.

Be glad it wasn't the Porsche towing it. :D

You used PVC rollers to get it up over the wall?

Will you just weld the fence back together?
 

RVDan

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Oct 9, 2011
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North America
Re: Structural Engineering: Where does this fail first?

That's quite the interesting design. I don't think I've seen that in even third world country's. Did you happen to help out that guy who built the Shed of Doom?:lol_hitti:beer:

Hey now, the shed of doom is still standing.
 
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Jack Olsen

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Mar 22, 2009
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Los Angeles
Re: Structural Engineering: Where does this fail first?

I love the Shed of Doom -- but aesthetics notwithstanding, I don't think this qualifies. Can anyone come up with a stronger design, made only of 2x4 stock, with as few cuts (since it's disassembled after the job), and as few pieces as this?

hAFBOr.jpg
 

kerrynzl

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Nov 8, 2013
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Location
Tauranga, New Zealand
Re: Structural Engineering: Where does this fail first?

^^^^^^^
2 x builders saw horses [saw stools] would've taken that load.

Cheap to buy as a kitset , and have multiple uses
 

davejo

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Oct 29, 2015
Messages
276
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(VA)
Re: Structural Engineering: Where does this fail first?

I love the Shed of Doom -- but aesthetics notwithstanding, I don't think this qualifies. Can anyone come up with a stronger design, made only of 2x4 stock, with as few cuts (since it's disassembled after the job), and as few pieces as this?

hAFBOr.jpg

If you made me subtract one element, I'd take away the bottom 2x4 and extend the center post to the ground. can we use bolts?
 

bczygan

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Nov 4, 2009
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DETROIT! Arsenal of Scrappers
Re: Structural Engineering: Where does this fail first?

I love the Shed of Doom -- but aesthetics notwithstanding, I don't think this qualifies. Can anyone come up with a stronger design, made only of 2x4 stock, with as few cuts (since it's disassembled after the job), and as few pieces as this?

hAFBOr.jpg

Proof is in the pudding.......it worked!
 
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