Framing for garage door

[428PI]

This opening is 16 ft wide by 14ft tall. I'm going to frame in for a 14x12 ft door so I need to come down around 1.5 ft by the time the concrete comes. I will build over 2 ft from the right side. The pic with angled braces is the opening getting the door. You can see in second pic what they did 50 years ago. Just hung a 2x12 with single brace and it also has to hold a lean to roof. I'm wanting the simplest method. The top beam is 2 2x8 now. For many years one angled beam wasn't even doing anything and just hanging plus the 2 2x8s held sliding doors.

 

[428PI]

I should add that I have plenty of 2x8's laying around. I'm really thinking of building a truss with angled bracing out of the 2x8's instead of ordering and having to install an double lvl beam which is more weight than I can handle. You can see in the second pic that the 2x12 is cracked and even sistered into the studs on the right and still doing it's job. When they build the shed they apparently used what they had. It's a pole shed built over existing barn foundation which a tornado took down in 1970. I plan on redoing that as I need to frame in a wall in place of the 2x12.

 

[Prospecter]

I've dealt with similar construction both in Mid-coast and Northern Maine, where snow load is a concern. Not the engineers' GJ correct answer, but I think you are on the right track. I tend to use 2x10 and 2x12 for situations like yours, but the 2x8's will probably work. Lighter, but you will need more. Check here: https://awc.org/calculators/span-options-calculator-for-wood-joists-and-rafters/
I would add doubled up cripple studs on each side of the opening just to give yourself more bearing surface on each side while you are putting the pieces of the header in place. (Keep a Big Hammer handy. Things often need a little encouragement.) Through bolt the pieces of header together when you are finished. I would probably do similar for the back wall, too. I probably would use diagonal bracing, too. One thing you've got going for you is 50 years of real world testing on this shed design. Improving the areas that aren't testing out well should get you another 50 years.

 

[firebirdparts]

Yep. that's mighty light, but it hasn't fallen yet, so it probably won't if you don't hang anything off it.

 

[428PI]

I just went out and measured the lower header in the 2nd pic and it's not even a 2x12. Only a 2x10!