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(07-20-2018, 05:02 PM)lift mechanic Wrote: Nice shed. 1 thing I do not see is any diagonal bracing on the center chord to keep the trusses from dominoing. the sheathing nailing helps. You made your own trusses with wood gussets, how hard were they to build? they look nice my next shed maybe I'll do the same.
I've never seen anything like that; got any photos? I've already overbuilt the trusses; I suppose I could add a couple of diagonals to make it bomb proof.
The trusses were easy to build, but not w/o a few issues. I made an outline on the shed floor to keep them all the same. If I were doing it again, I would screw cleats to the shed floor, around the outline. That would make it easier to get the top chords really straight and the overall dimensions exactly equal. Between some minor variations in the build, combined with some minor left/right positioning during setting the trusses, a couple of them were 1/4" or a little more higher on one side or the other. When I laid a 2x4 over the top chords it would rock in some places and bang into a top chord in another. Some of that I got rid of by sliding the trusses left/right, but I ended up using a power hand plane (which worked great) to trim down the remaining high ones so that the 2x4 slid without rocking or hitting a top chord. It didn't take long, actually, but not something I enjoyed doing. I have no idea how consistent factory built trusses are; mine were within 1/8" when I was done.
John
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Its a bottom truss brace John. Just runs the length of the building on the lower part of the truss.
I don't think one is necessary after you already have them up and sheeting is on.
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(07-20-2018, 05:02 PM)lift mechanic Wrote: Nice shed. 1 thing I do not see is any diagonal bracing on the center chord to keep the trusses from dominoing. the sheathing nailing helps. You made your own trusses with wood gussets, how hard were they to build? they look nice my next shed maybe I'll do the same.
Is this what you mean?
Link
John
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(07-20-2018, 09:52 PM)jteneyck Wrote: Is this what you mean? Link
John
You're done sheathing, so that brace isn't absolutely needed ( the plywood will keep it from racking
If the trusses stay plumb) What you should have is something to keep the bottom chords from bowing left or right, continuous from gable to gable to keep the ends from bowing in or out in a strong wind, It can be strapping on the bottom, plywood on top for storage floor, or just a dbl. 2x from end to end. With option 3, the Inspector may want two or more rows and also diagonal bracing from side walls to gable ends.
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07-21-2018, 01:13 AM
(This post was last modified: 07-21-2018, 01:16 AM by lift mechanic.)
The second example is what I was talking about. It was recommended by the truss company. If you built all the trusses and kept them to within 1/4" that is as good as the trusses I had built. I could really see some differences on the two trusses that were 4 trusses bolted together for a 32' span. These were attic trusses and there was some differences especially in the diagonal supports within the truss.
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(07-20-2018, 11:45 PM)MstrCarpenter Wrote: You're done sheathing, so that brace isn't absolutely needed ( the plywood will keep it from racking If the trusses stay plumb) What you should have is something to keep the bottom chords from bowing left or right, continuous from gable to gable to keep the ends from bowing in or out in a strong wind, It can be strapping on the bottom, plywood on top for storage floor, or just a dbl. 2x from end to end. With option 3, the Inspector may want two or more rows and also diagonal bracing from side walls to gable ends.
I plan to add horizontal diagonal bracing between the side walls and gable ends. 2 x whatever length it takes to go from the mid point of those walls and screwed to the walls and under each truss bottom chord. That will address and twisting of the building in high winds. The diagonal bracing in the vertical plane of the trusses to the gable ends will take care of keeping the bottom chords aligned.
(07-21-2018, 01:13 AM)lift mechanic Wrote: The second example is what I was talking about. It was recommended by the truss company. If you built all the trusses and kept them to within 1/4" that is as good as the trusses I had built. I could really see some differences on the two trusses that were 4 trusses bolted together for a 32' span. These were attic trusses and there was some differences especially in the diagonal supports within the truss.
Thanks, and thanks for bringing up this topic in the first place. The more I though about your comment the more sense it made, so I went looking and found the reference above, as well as many other comments and design guidelines. It would take a big wind to make the trusses domino now, but a few 2x4's are cheap insurance and I will add them tomorrow. When I think about the commercial sheds I looked at, it's clear mine will be a lot better built - thanks to your collective help.
John
