Timeline for Flushing LVL up when not as thick as wall?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
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| Dec 14, 2021 at 15:15 | comment | added | P2000 | "I also like foam in middle" what kind of foam? If not XPS, will it breathe and where is the vapour barrier? | |
| Dec 14, 2021 at 13:11 | comment | added | CCCBuilder | isherwood I agree, I see most LVL documents showing the plies nailed together. I would do this in a traditional beam (like basement) or like @P2000 mentioned when having joist hangers used, because then you literally are only bearing weight on ONE of the TWO LVL members. However in this scenarior, where a top plate is apply even surface area to two identical LVL (bearing on trimmers at same points) I do not feel nearly as concerned. I also like foam in middle for exterior headers. A 2x6 wall allows this. | |
| Dec 12, 2021 at 1:46 | comment | added | isherwood | My family typically built our exterior wall headers in a U-configuration and insulated them before installation. This preserved backing over the window for trim, window treatments, etc. | |
| Dec 12, 2021 at 1:12 | comment | added | P2000 | Headers in exterior walls have their cavity on the inside rather than between the plies so that insulation can be applied after framing. Multiple plies of beams are fastened to each other to handle side loads (joist or beam hangers); also if point loaded by joists/cross-beams/posts, I believe to avoid buckling along the depth or shifting of the plies, causing one ply to bare more load than the other. | |
| Dec 11, 2021 at 16:21 | comment | added | isherwood | Weight distribution isn't really a concern here. They're on the same trimmer studs or posts, and it doesn't really matter where they sit. There are certainly many ways to secure the beams. I'm only relating common practice. Where twin LVLs are specified they usually have an attachment schedule. YMMV. | |
| Dec 11, 2021 at 14:47 | comment | added | CCCBuilder | I've always done this as well but I'm very curious what the difference is in a situation where each LVL is bearing the same? There is a flat top plate above the lvl that holds the top of the lvl from pulling out, blocks in the center void with structural lags, and then the bottoms are secured to the load bearing posts on each end. The footprint of weight is now distributed more equally than if one side of the wall had both lvl flushed up. | |
| Dec 7, 2021 at 17:51 | comment | added | isherwood | Edited to clarify. Usually when beams are doubled it's required that they be connected mechanically using appropriate fasteners. The new beam then becomes greater than the sum of the parts in terms of load rating. If you space them out you'd have to come up with the equivalent fastener of a much longer length, and you'd have to provide spacer blocks that are structurally suitable. I wouldn't risk degrading beam performance with such an approach, as a matter of best practice if not specific requirement. | |
| Dec 7, 2021 at 17:50 | history | edited | isherwood | CC BY-SA 4.0 |
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| Dec 7, 2021 at 17:28 | comment | added | P2000 | Yes, "They generally need to remain fixed together" is my understanding too, with sometimes allowance for a 1/2in plywood sandwich up to make things flush, but what do you mean with "You don't want to have to try and tie heavy members together with fasteners"? | |
| Dec 7, 2021 at 16:51 | history | edited | isherwood | CC BY-SA 4.0 |
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| Dec 7, 2021 at 15:37 | history | answered | isherwood | CC BY-SA 4.0 |