Author Topic: Attach LVL beams to 6x6 post?  (Read 571 times)

trammatic

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Attach LVL beams to 6x6 post?
« on: October 12, 2017, 07:50:08 AM »
I'm putting in a roof structure using hipped roof trusses.  The engineer said that 6x6 posts in the corners would be sufficient, but I can't figure how to attach two lvl beams in the corner while still having them both bear on the post.  Would mitreing the beams provide sufficient bearing?  The engineer said that post caps would work, but I don't know what kind he's talking about.  Any ideas?

hoosier

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« Last Edit: October 13, 2017, 08:16:44 AM by hoosier »

bacchi

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Re: Attach LVL beams to 6x6 post?
« Reply #2 on: October 12, 2017, 06:03:36 PM »
By "mitreing," do you mean notching them? Never, ever, do that to an LVL. The structural engineer for my new place flipped when he saw that the framing crew had done exactly that.

mrmoolaman

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Re: Attach LVL beams to 6x6 post?
« Reply #3 on: October 12, 2017, 08:32:57 PM »
What size are the LVLs? If they are small enough, say 3.5 inches, then you can just run one of them through, and butt the other one into that beam. Run the one through that is supporting more load.

If you are going 3 ply, then you probably won't be able to do what I described above. Then I would ask the engineer if it's okay with them if you run two of the plys onto the beam, and cut the third ply short so that there is room for bearing. This would typically be okay, they just have to check, as it varies case by case depending on the loading and the shear/moment diagrams and capacities of the material.

paddedhat

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Re: Attach LVL beams to 6x6 post?
« Reply #4 on: October 13, 2017, 05:30:45 AM »
Seems to me that the engineer involved should provide a bit more direction. If you are using a single 1-3/4" ply, which could be the case on a smaller structure, I would notch the top of the post to full width bearing, and through bolt with 1/2" hex head bolts and washers. Beyond that, given the difficulty of landing two bearing beams on 30 sq. inches of bearing, the custom Simpson brackets linked in the second post would be the only acceptable solution IMHO.

Jmoody10

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Re: Attach LVL beams to 6x6 post?
« Reply #5 on: October 13, 2017, 05:34:08 AM »
We had to do something like this when building our house. We ended up using a simpson bracket.

trammatic

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Re: Attach LVL beams to 6x6 post?
« Reply #6 on: October 14, 2017, 12:17:21 PM »
So, including the depth of the footer, I need 6x6x12s, which are about $35 each.  Those simpson brackets are about $150 each.  I think I'm just going to go with 3 posts in each corner in an L-shape pattern so that each dimension's lvl can bear on a separate post. (Spend an extra $70 to save $150...)  I'll then use 1x12s to "wrap" the post columns for the nice look of beefy columns.

Thanks for the input!!

paddedhat

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Re: Attach LVL beams to 6x6 post?
« Reply #7 on: October 14, 2017, 01:21:32 PM »
Sounds to be a really smart choice. Be sure to bolt those 6x6s together, I would use a 1/2" X 10" hex bolt with washers, and recess the end in. One bolt, centered, ever two feet, or so.  The reason being, if you skip that step and do a nice column wrap, at least one of those 6x6s will decide to bow away from the group and bust the wrap apart. If you have a battery impact driver, you  could also clamp them together with some of the 10" timber screws used for landscape ties, and deck building. I would install these in pairs, though.
« Last Edit: October 14, 2017, 01:34:55 PM by paddedhat »

trammatic

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Re: Attach LVL beams to 6x6 post?
« Reply #8 on: October 14, 2017, 01:44:30 PM »
I was thinking a carriage bolt...why a hex bolt instead?

paddedhat

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Re: Attach LVL beams to 6x6 post?
« Reply #9 on: October 14, 2017, 02:17:00 PM »
I was thinking a carriage bolt...why a hex bolt instead?

IRC codes covering your area actually do not recognize carriage bolts for structural applications. Since the head is designed to dig in and "seat" into the bored hole, with no provision for a washer, it doesn't really have a calculable design value for loads imposed on the head. I used to use a lot of galvanized carriage bolts for deck building, and often tightened larger nuts with a half inch drill with a cut off socket extension in the chuck. This is where I first noticed that you could easily suck even a big carriage bolt head deep into a wet treated timber. Once codes were in play, back in 2006, it became standard procedure to use galvy hex bolts with washers on both sides.

All that said, these things are the ticket for this job, no predrilling, and quick easy installation

http://www.homedepot.com/p/FastenMaster-10-in-TimberLok-Coarse-Steel-Hex-Head-Heavy-Duty-Wood-Screws-50-Pack-FMTLOK10-50/202268252