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KemoSabe
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Discussion Starter · #1 · (Edited)
I had an idea to test wood X-bridging. Here is the setup.
I built a mock floor with 2' 2x10s, used 7/16 OSB for decking, 1x3 firring strips for bridging, stapled with 2" 7/16 crown staples(3-4 per end, as I typically would.) Obviously the floor is severely underbuilt. I nailed a 2x6 "box" to only the end joists to prevent them from just kicking out as weight was applied. You can see in the last pic that the field joists are shorter. The first pic is before the bridging was stapled.
Here is where the fun begins.
1. How much weight can be loaded above only the center joist before catastrophic failure?
2. Any guesses what the point of failure will be?
 

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KemoSabe
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Discussion Starter · #2 ·
Here is the complete system before applying weight.
 

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Curmudgeon
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More than you'd expect?
Less than you'd hope?
The weight of a Lone Framer? :laughing:
 

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KemoSabe
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Discussion Starter · #6 ·
More than you'd expect?
Less than you'd hope?
The weight of a Lone Framer? :laughing:
I did get up there to test it out, but I want to see some guesses before I tell you what happened.:laughing:
 

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Maker of fine kindling
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Well you did it. Good for you.

I still say 220 lbs

And the cause of failure is the bottom connections on the outer most bridging pulled away and I hope you got your feet out of the way when it went kaboom.
 

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KemoSabe
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Discussion Starter · #8 ·
You haven't had a date in awhile have you? :laughing:

My hat's off to you man, test the "theories". I personally have never been a fan of bridging, but I understand the use.
Had a date with the ballet instructor 2 weeks ago.:thumbup:
I got the idea to test bridging a few days ago, couldn't let it go.
 

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I'll say 800 lbs
 

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Contractor
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700 lbs.

And I have no idea the cause of failure, but you should probably refer to it as the point of failure, the weakest link. The cause is, of course the excess weight.

edit: How did you add weight?
 

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Jeff
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I'm gonna guess it held a loneframer, the ballet instructor, a case of beer but failed when the pizza delivery guy slammed dinner down. If it wasnt for the 3 meat bonanza the ballet instructor had to have it might have held. And it failed at the anchor of the 2x6 first causing a chain reaction and alot of shook up beer.
 

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I'm not clear what you are exactly trying to test here? Is it the strength of the joist or the X-bridging?
 

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KemoSabe
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Discussion Starter · #15 ·
700 lbs.

And I have no idea the cause of failure, but you should probably refer to it as the point of failure, the weakest link. The cause is, of course the excess weight.

edit: How did you add weight?
Centered 2 ten pound plates over the center joist, then started adding 50s.
 

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Super Moderator
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Why not repeat the setup without the bridging? I am guessing thats where this is headed. Quick somebody alert the engineers that they are about to be proven WRONG!!!!
 

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KemoSabe
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Discussion Starter · #17 ·
I'm not clear what you are exactly trying to test here? Is it the strength of the joist or the X-bridging?
The ability to transfer and share load over the whole assembly using wood bridging.
 

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Maker of fine kindling
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If you had something tying the horses together it would have held more weight.


I think
 

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KemoSabe
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Discussion Starter · #19 ·
Why not repeat the setup without the bridging? I am guessing thats where this is headed. Quick somebody alert the engineers that they are about to be proven WRONG!!!!
This is pretty much what it would look like minus the box across the end joists:eek:
 

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KemoSabe
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Discussion Starter · #20 ·
If you had something tying the horses together it would have held more weight.


I think
That is what I thought would start the failure, it is not the case.:no:
 
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