Lag bolts holding lvl beam on pergola
Lag bolts holding lvl beam on pergola
(OP)
Have a situation where 2 ply lvl beam is bolted to columns the side of the columns instead of bearing on the top. Bolts are snuggly fastened together. Any potential issues having it done this way ?
RE: Lag bolts holding lvl beam on pergola
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RE: Lag bolts holding lvl beam on pergola
RE: Lag bolts holding lvl beam on pergola
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RE: Lag bolts holding lvl beam on pergola
RE: Lag bolts holding lvl beam on pergola
RE: Lag bolts holding lvl beam on pergola
RE: Lag bolts holding lvl beam on pergola
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RE: Lag bolts holding lvl beam on pergola
RE: Lag bolts holding lvl beam on pergola
1) Interestingly DC6 for decks prohibits this kind of connection. I've always wondered if that prohibition only applied to non-engineered solutions though. Certainly, I've seen plenty of examples of similar connection in other engineer's drawing in the past.
2) If the numbers work on the bolts, I'd think this would be ok. Shrinkage ought not be a problem for engineered lumber. Is this pressure treated PSL? If it's LVL, it's probably not treated which might present a problem in an outdoor application.
3) Assuming that's a 6x6 post, your load eccentricity on the column would be about 4.5". It's probably alright for smaller loads but, at the same time, it's easy to check and I'd be inclined to check it.
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RE: Lag bolts holding lvl beam on pergola
RE: Lag bolts holding lvl beam on pergola
- Looks like run of the mill checking to me which is, of course, another shrinkage induced phenomenon.
- With respect to the post, the bolt layout is really optimal for not inducing shrinkage restraint across the member.
- If the connection is responsible at all, I'd think that it would be by way of accidental joint fixity attempting to behave as a moment connection. That's not my feel for the situation though.
HELP! I'd like your help with a thread that I was forced to move to the business issues section where it will surely be seen by next to nobody that matters to me: http://www.eng-tips.com/viewthread.cfm?qid=456235
RE: Lag bolts holding lvl beam on pergola
RE: Lag bolts holding lvl beam on pergola
RE: Lag bolts holding lvl beam on pergola
RE: Lag bolts holding lvl beam on pergola
1) As KootK pointed out, LVLs should NOT be used outside. I like to think of them as really thick plywood - have you ever seen plywood after it gets wet a few times? Even exterior rated adhesives is susceptible to long term wetting (or even short term along the edges where the moisture can work in between the plies).
2) Temperature and moisture variations combined with variable wind loading will loosen the connection over time. If you let the beam into the post, no big deal - just tighten them periodically if you notice it. Like this, the failure is more likely to be sudden and catastrophic. Letting it in may not be a requirement for engineered connections, but from a judgement standpoint I don't detail exterior connections without bearing unless it's absolutely unavoidable. In those cases I try to develop some additional redundancy. Unless I'm mistaken, the DCA6 was written in response to a demand to reduce residential deck collapses and the associated injuries. While other engineering options may be available, these are "best practices" to help ensure a resilient structure and I'm hesitant to provide a "less" resilient design.