• schmidtster@lemmy.world
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      2 years ago

      It’s used so the other trades don’t wreck all the TGIs by putting incorrect penetrations. It has all the holes they could possibly need, but sometimes they’ll stick cut a plate….

      • TheHarpyEagle@lemmy.world
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        2 years ago

        How are floor trusses different from regular floors? What are TGIs and incorrect penetrations?

        Thank you if you have time to answer.

        • schmidtster@lemmy.world
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          2 years ago

          There isn’t really any type of “regular” floor in wood, but the 3 most common are dimensional lumber (2x10s for example), engineered joists (TJIs which are dimensional top and bottom chord and OSB web) and engineered trusses (what you see here, dimensional chords and webs.

          I apologize for that typo, it’s TGI I-Joists, explained above briefly. The incorrect penetrations can happen in either dimensional joists or engineered joists. The easy rule of thumb is no more than 1/3 the diameter of the material (9” joist being 3” max) and has to be in the inner 1/3 (9” again so no holes within 3” of the top or bottom of the joist.

          Now most engineered joists come with pre penetrations and any deviation without their express consent can void their warranty, BUT following general guidelines shouldn’t lead to any issues.

    • nomecks@lemmy.world
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      2 years ago

      I’m seeing them more and more, which means OSB is probably too expensive to use for engineered trusses now.

      • schmidtster@lemmy.world
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        2 years ago

        It’s a trade off, more expensive, but you’re not replacing them because some trade made an incorrect penetration.

        Basically you’re paying more to prevent issues later.