I have some 11 7/8 TJI joist, and was going to use them for headers.
They have a 3" chord.
My garage door opening is 12 foot wide, and there will be a 2nd floor, my original plan was a double 2x12.
Do TJI's make good headers?
Don't do it. They will not be strong enough and have very poor lateral, out of plane strength, a concern with many garage door headers to begin with. I kind of doubt the double 2x12 is sufficient depending on floor and roof arrangement. With a sketch we can probably figure it out.
The other big reason not to do this is, any damage to the bottom chord will make it fail. Too tall of a load backed into a garage isn't a rare occurence. Garage fires are pretty frequent, too, due to cars, water heaters and stored flammable liquids---rapid burn through of that same bottom chord will cause a very rapid collapse in a fire. During smoky fires peole tend to try to exit through whichever entrance they use most frequently, which is often the garage. Having a good solid header will help provide a reliable means of egress in the event of a fire.
Thanks Don and flyingvan...
I talked to my engineer also, and ordered 3 14 foot long 11 7/8 lvl's, and was told to put them ona 2x6 wall.
He basically said the same thing you said Don....not strong enough or made for that application.
That is a lot better choice of materials but more $$$ but a lot more stable.