• debris_slide@lemmy.world
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    2 days ago

    Much better. Imagine you’re bending something. The maximum tension is going to be at the very bottom and the max compression is going to be at the very top (this is why steel I-beams are shaped the way the are - to put the most material in the areas doing the most work). If you can put the hole in the middle you’re not impacting the structural integrity of the joist too much. You’d still have to worry about shear forces so you’d not want the hole to be too close to either end. Look up “castellated beam” if you want to see some steel examples.

    • Sigilos@ttrpg.network
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      2 days ago

      Why not just use hangers? No way a metal bracket doesnt exist for hanging pipe from joists. DIY some metal wire and a screw to hold it if you have to, hang that sucker like fresh venison, but why cut existing structures?

        • Sigilos@ttrpg.network
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          2 days ago

          I meant structure as in existing stuff, not ‘structural’ as in load-bearing. Extra wood would indeed still count as ‘structure’ within the context I meant.

          This is, however, not just extra wood. What was cut through in the picture is floor joists, which are what holds up the flooring and supports whatever is on the floor, including people and furniture. Cutting these joists severely compromised the integrity of the floor. Now instead of a squeak from stepping in that spot, it’s far more likely that a loud crack followed by a fall through the floor will be the result of a heavy step.

    • 4am@lemmy.zip
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      2 days ago

      A joist hole can be no more than 1/3rd the total depth of the joist, I think that pipe is larger than that. Even if you placed it in the very middle you’d still be compromising the structural integrity.

      Best to just get some hangers and a fix it to the bottom; you’re still well clear of the ground. Put in some shims near one end if it’s a drain and you have to maintain pitch; I think this is a thick electrical conduit though?

      EDIT: nope that looks like 4” PVC drain pipe