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Thread: Civil/Structural Eng Roof Truss Question

  1. #1
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    Civil/Structural Eng Roof Truss Question

    I ended up doing a simple calc to check if this steel beam was up to the task for this local guy. While the beam was fine I questioned what he was doing above. Above the floor he was going to have a 5' pony wall with the pictured roof truss . I would really be worried about the outward forces pushing out the pony wall.

    One option I was thinking of would be if he hasn't bought the roof truss use a common or attic roof truss . With the pony wall being replaced by a full wall like 8'. ]

    Or maybe tie the pictured trusses at 8' maybe 4 times over the 30' length?
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    Mrs. Dougw- "I can see how one of your relatives could have been killed by an angry mob."

    Quote Originally Posted by ill-advised strategy View Post
    dougW, you motherfucking dirty son of a bitch.

  2. #2
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    lotta unanswered ques here - no local engineer?

    not sure what an 8' wall does different than a 5' wall if they're both unbraced, just a bigger moment arm at the top

    online TRG engineers will want more info to understand the big picture

  3. #3
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    Most engineered trusses, by definition, do not have an outward thrust. You can ask the truss company for the loads and that will tell you. I’ll bet they say the loads are vertical only. That’s why it has the nearly horizontal interior tension members tying the top and bottom chords together. Truss company engineer should have all that info.

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    Bigger question--do I want to be in a building in the Canadian Rockies in the winter with a roof engineered by TGR?

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    Quote Originally Posted by EWG View Post
    Most engineered trusses, by definition, do not have an outward thrust. You can ask the truss company for the loads and that will tell you. I’ll bet they say the loads are vertical only. That’s why it has the nearly horizontal interior tension members tying the top and bottom chords together. Truss company engineer should have all that info.
    Ok , trusses like that i have no experience with but looking more closely at drawing they do have the loads on them and the HORZ is zero, so there is no load on the pony wall other than the vertical.
    Mrs. Dougw- "I can see how one of your relatives could have been killed by an angry mob."

    Quote Originally Posted by ill-advised strategy View Post
    dougW, you motherfucking dirty son of a bitch.

  6. #6
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    Quote Originally Posted by ::: ::: View Post
    lotta unanswered ques here - no local engineer?

    not sure what an 8' wall does different than a 5' wall if they're both unbraced, just a bigger moment arm at the top

    online TRG engineers will want more info to understand the big picture
    If an 8' wall then can have joists run between the two walls. Can't do that with a 5' pony wall unless everyone in household was 4'-9" tall.
    Mrs. Dougw- "I can see how one of your relatives could have been killed by an angry mob."

    Quote Originally Posted by ill-advised strategy View Post
    dougW, you motherfucking dirty son of a bitch.

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    Quote Originally Posted by DougW View Post
    Ok , trusses like that i have no experience with but looking more closely at drawing they do have the loads on them and the HORZ is zero, so there is no load on the pony wall other than the vertical.
    The wall and the truss/wall connection will have a dead load and live load too, but it'll all add up to dead load on the foundation.

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    Id build it then jump ip and down on the croof to test it

  9. #9
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    Wind and/or Seismic loading on your walls >> dead load outward force imparted by roof truss via simpson straps or lag bolts from the truss to the wall

    This is why OSB shear walls are a thing.
    Wait, how can we trust this guy^^^ He's clearly not DJSapp

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    Quote Originally Posted by old goat View Post
    Bigger question--do I want to be in a building in the Canadian Rockies in the winter with a roof engineered by TGR?
    What could go wrong?

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    Quote Originally Posted by old goat View Post
    Bigger question--do I want to be in a building in the Canadian Rockies in the winter with a roof engineered by TGR?
    I would take my chances in the Rockies, but not in the Columbias.

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    Quote Originally Posted by Dr. Adirondack View Post
    I would take my chances in the Rockies, but not in the Columbias.
    Tits or gtfo.
    swing your fucking sword.

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    Yer gonna die..
    Go that way really REALLY fast. If something gets in your way, TURN!

  14. #14
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    Quote Originally Posted by DougW View Post
    If an 8' wall then can have joists run between the two walls. Can't do that with a 5' pony wall unless everyone in household was 4'-9" tall.
    You got something against short people?
    Quando paramucho mi amore de felice carathon.
    Mundo paparazzi mi amore cicce verdi parasol.
    Questo abrigado tantamucho que canite carousel.


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    Quote Originally Posted by Dr. Adirondack View Post
    I would take my chances in the Rockies, but not in the Columbias.
    I hear the Big Belt and the Blue got beavers big as bobcats.

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