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This is mostly a warning
often those of us in the industry ignore some of the safety precautions on the products we use every day and generally don’t think anything of it, because we are trying to get the job done in the shortest amount of time possible, untill–
Crash!!!
Two days ago we were rolling I joist, after we finished I had my laborer start Bringing up sheets of 3/4″ plywood and Stack it up on the I-joist after he finished there were about 35 sheets of plywood setting on the I-joist. He and Another Contractor that I work with were standing upon the Stacks of I-joist Getting ready to set the first row of sheeting. not making any movements they were just standing there. The I-joist must have tipped very slightly when without even a seconds warning 5 I-joists collapsed leaving both workers unhurt, 9 feet below on the first floor deck, It scared the living daylights out of all of us. Thank goodness nobody was hurt.
The amazing part of it to me was the joist were only 18 feet long and nailed securely in a hanger at one end and to a rim board on the other
So I guess what I am trying to say is don’t do what I did and don’t just throw those installation instructions in the scrap pile like I have so many times:-(
Does anybody have a similar story?, I think passing storys like these on could possibly save someone from getting hurt or even killed!
Replies
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mid span blocking. bridging. point loads.
*Flimsy stuff until it's all a part of a finished system.MD
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Good Idea!
Not Required though by my local Codes.
They usually do a computer generated takeoff, and I guess because they are continuous, blocking is not required?In this situation I had trusses above so there was no point bearing. All the bearing was floor load. But those are a good idea anyway!
Rob C
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That's very scary stuff. I'll be doing the same thing on a 21' span. What happened and what will you do to prevent it again?
*I would not suggest staging over 1 ton of plywood in one stack - in the middle of a span of i-joists and then standing on it.....If you're going to stage all the sheathing, at least put it at the edge, on the rim joist, where the joists are perpendicular to the rim.IMHO, jim
*somewhat similar story look in "wall jacks what do you use and how do you like them"advice: sheet first row and then about three sheets on second row then stack remainder of sheets on floor and be careful jim
*> The amazing part of it to me was the joist were only 18 feet long and nailed securely in a hanger at one end and to a rim board on the other You're not looking at it the right way - The things are 18' long and only about 1.5" wide. The extra weight simply caused them to fall over. I went out and looked at some floor trusses on a house today that had a bunk of lumber set out in the middle of them i afterthe subfloor was installed. The extra weight pulled some of the plates partly out, and caused the floor trusses to sag about an inch. They're looking at an expensive repair now.
*"over a ton" of weight on the 32 sq ft of a stack of 4x8 sheets is around 70 psf of live load; kind of a lot compared to typical design loads for finished residential framing. It's calculations like this that make me sometimes realize that we subject what we build to more stress than it is likely to ever see in use, or be designed for. Just a thought, keep your mind working on the site.... Rich.
*I joists are designed to handle specific kinds of loads, they are an engineered product, not capable of achieving their specified design load until the "system" is complete. Even then, they perform differently than dimension lumber. Thanks for the warning though, glad to hear no one was hurt.
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Most of the comments that were posted I think were a good solution
and a much safer way to go about applying sheeting down to the TJI's
The way I will go about it next time will be to run a 2" X 4" nailer
accross the center of the run of TJI'S and Run one row of sheeting before stockpiling any material on the joist.
It made me realize how many things get done without to much thought to the possible consequences. I had done the same thing probably 20 different times with TJI's and over 100 times with traditional 2X10 and 2x12
All that to say because we've done it before doesn't mean it is safe
I just hope posting this keeps somebody from doing the same thing
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One thing I was taught was to order a bunch of furring strip to nail down every 8' or so to keep joists and trusses on centers. Cheaap and better than a bunck of 24" blocks. (or 16") The furring we later used as drywall blocking were needed.
Good tip about running the first row. We never staged our lumber in bulk loads. Around here everything comes in a complete package at once and is sorted by wall and floors into smaller groups.
This really helps out when the crew setting sills and laying out the walls, etc., is working because the other few people are making the rest of the job run smoother with a little prep work.
AE
*well- keep them installation papers around and mebee look at 'em sometime. they are pretty straight forward so's even us carps can read 'em. also got lots of usefull info about drilling and cutting holes- how big and where for the plumbers and heating men. I always tack 'em up for the folks that come after...so how come you bothered stacking the ply? 35 sheets? coulda snapped a line and had two thirds of them glued and nailed in the the time it took to stack 'em- and you wouldn't have to handle them again...anyway- glad everybody is ok
*Rob, This exact situation occurred to us a couple of years ago! Only,there were two guys standing right underneath the stack of plywood just 30 seconds before the collapse ! To this day I still marvel at what a close call that was! Now I'm feeling kinda guilty about not sharing that story on this board. Nailing a layout board at midspan seems to have been the most effective solution for us. Thank you for the warning to everyone, I certainly hope it saves someone from a similarly perilous incident in the future!
*Mark, don't kid yourself about that mid span board. If you insist on staging overloads, that mid span board will only be false security.Most often staging is double handling. If you are using a forklift, just put a few, enough to stablize the section, then stage the bigger load. We do ours by hand. If it's too tall on the exterior, we'll often just hump them upstairs and bang them home.Often, we stage them on "ladder racks". Were are limited to approx 7 sheets, but who wants to continuously carry more than that at any given time?blue
*Wouldn't a midspan board just ensure that the joists would fall over in unison?
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We run 1x4's every five to six feet as runners and even then we don't stack plywood on the joist.
As one of the gentleman posted before, why move the material twice?
Only after we have a plywood row glued and nailed down with ring shanks do we load the rest of the plywood up, if we have to, otherwise we just keep sheeting the floor.
WORK SMART, NOT HARD
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This is mostly a warning
often those of us in the industry ignore some of the safety precautions on the products we use every day and generally don't think anything of it, because we are trying to get the job done in the shortest amount of time possible, untill--
Crash!!!
Two days ago we were rolling I joist, after we finished I had my laborer start Bringing up sheets of 3/4" plywood and Stack it up on the I-joist after he finished there were about 35 sheets of plywood setting on the I-joist. He and Another Contractor that I work with were standing upon the Stacks of I-joist Getting ready to set the first row of sheeting. not making any movements they were just standing there. The I-joist must have tipped very slightly when without even a seconds warning 5 I-joists collapsed leaving both workers unhurt, 9 feet below on the first floor deck, It scared the living daylights out of all of us. Thank goodness nobody was hurt.
The amazing part of it to me was the joist were only 18 feet long and nailed securely in a hanger at one end and to a rim board on the other
So I guess what I am trying to say is don't do what I did and don't just throw those installation instructions in the scrap pile like I have so many times:-(
Does anybody have a similar story?, I think passing storys like these on could possibly save someone from getting hurt or even killed!