[Nealtw]

2x4s are never headers, plates lay flat, headers stand on edge.

 

[Nealtw]

Yes, I understand that. I am assuming the deflection on a 2x4 header at a given uniform load and span will give me some rough idea on how much a 2x4 plate connected to the top of a 2 ply LVL will stiffen it against a lateral wind load.

How long s the LVL, once a double is nailed together they are pretty stiff on there own.

 

[Nealtw]

Let me say a little more about my issue. I could have continued my garage header thread but this is a little different animal. Major LVL suppliers, eg LP and Weyerhaeuser, have user friendly apps to design LVL headers for vertical loads. They also let you calculate horizontal deflection for lateral wind loads on single ply beams ONLY. They told me they will not help users design a two ply LVL with a lateral wind load because the math is too complicated and unreliable. They say the only way you can use a two ply LVL exposed to a lateral (perpendicular to beam) load is if it is designed by an engineer. I talked with Simpson about their structural fasteners and they said the same thing. I have learned that it is it a simple task to design a LVL beam for vertical loads but impossible for lateral wind loads.

Hmm, I didn't put the two threads together. In the other thread I think I did explain that we use a full 2x10 for what would be the door jam, that would add much to the strength,, you also want to look at the height I guess of you are right up close to the roof that would be better than if it was dropped 2 feet. I haven't seen it even considered before, we always put the beam right under the roof and often build down from that to the door height, some times that approaches 4 feet hanging from the beam with a 2x6 wall, but a big wind here might get to 65 mph.

 

[Nealtw]

My 18’ garage door header will be a “drop” beam with a 5’ high pony or cripple wall above it. The cripple wall connects to the bottom chord of the structural truss above it (non load bearing gable end). So, the force from the wind blowing normal to the pony wall will be transmitted to the header and the attic framing. The pony wall is only 90 sq ft so normally not a big deal, but more problematic if you design for 90-100mph. Since none of the software apps will do this calculation for you, you either have to guess or hire an engineer.

Or rebuild the wall out of 2x8 or 2x10, would be cheaper than an engineer. :biggrin2:Can you find similar garages to see what has been done and has past the test of time. Or on the more ugly side angle bracing from above the door to the trusses above.

 

[Nealtw]

I just watched the video on wall bracing for wind by the APA, they show a door similar to yours and say nothing about that wind resistance.

You could try contacting them with a question.

https://www.apawood.org/wall-bracing-webinars

 

[Nealtw]

I am just stepping in here. What are the dimensions you are after? What material properties are required? Allowable deflection? Is this going to be an inspected element by code enforcement?

There is little to no load from above, the concern is wind resistance with a double 9" lvl.

 

[Nealtw]

I am wondering why we need an LVL? I have a few thoughts but I'd like to know the details. Is the LVL the only thing that will fly with the code man?

I am guessing that a sandwich of LVLs, or any other lumbers, oriented as I assume, will be disconnected at the neutral axis in that direction of lateral deflection.

Depending on the loads and requirements, there are a few other ways to fix this. I need to know what the allowable wall deflection is.

With out much load from above the need for support is minimal and he will be removing 2x10 headers, full length 2x10 could sag under there own weight. The two ply LVL seems like a good way to go. but then the wind issue came up, the gable should be fine and maybe a few mores 2x4s can be added above the lower members of the trusses, I have seen things done about that. The problem is the beam is some distance below the gable.

So then you look at the bend sideways in wind or even if it holds stiff the next issue would be the connection of the beam at the ends.


I have ideas that I would discuss with an on site engineer but I would not suggest anything because it is out of my experience.

 

[Nealtw]

No worries guys, I have already decided to go with a single ply 3-1/2” PSL beam. The current debate is why beam manufacturers will not recommend a multi-ply LVL beam with a lateral load or provide technical guidance to help someone design one.

I do not believe winds have ever reached 90 mph in this area in my 70 year life time. And, it they ever do, what is the chance it will be normal to my gable wall? I am designing for a case that will never happen, but that is just the way I am wired. I never want to spend two seconds wondering if my multi-ply LVL will stand up to a strong wind.

Great info and different than seismic most everything we do is craned in micro lam and we get LVLs if we have to place them by hand. :wink2:

 

[Nealtw]

Deleted.

There is more to think about. Racking is a consideration, engineers solve that with a nailing pattern on the sheeting on the outside, unless you are stripping siding you don't have that ability.
If you had 2x6 walls the trick is to leave one 2x10 which has the sheeting nailed to it and add the the LVLs inside that and nail the first one to the 2x10.
that's not available either if you are using a beam.
You may want to sheet the inside to tie everything together.

 

[Nealtw]

Great minds think alike. I removed enough 5/8” Sheetrock to inspect the existing framing. No insulation! I was thinking about removing the rest of the Sheetrock to insulate and putting sheathing back up. I am not concerned about racking since that gable wall only projects a foot or so beyond the adjoining room. At one point I was thinking of installing brace panels in the narrrow wing walls to prevent racking but talked myself out of that.

Older garages that were sheeted with ship lap rack all the time, we just sheet the inside with osb when we have them straight.