The procedure for constructing a header for 6 inch exterior wall framing can be modified for any wall thickness.
Wood beam over garage door.
The result of this continuous garage door header not being adequately braced led to the wall bowing.
We always build garage beams with 2x12 s and 1 2 osb usually on a 16foot opening a 2x12 with a 2x6 on top will suffice put a rip of osb in between with plenty of construction adhesive and nails and on the other side reverse the 2 x s 2x12 on top of 2x6 on one side 2x6 on top of 2x12 on the other this will leave you with a beam about 14 3 4 tall enough for a standard 7 garage door on.
Continuous garage door header.
Building a structural header for a garage door opening can be handled on the jobsite and will offer the same structural support as more expensive solid wood beams.
Usually in a wood frame house there will be a wood header beam supporting the garage door opening the metal lintel supports only the brick facade and is bolted to the beam.
Window door garage door headers supporting roof loads only.
Width of garage door opening standard widths are 8 9 10 12 14 16 17 and 18 height of the garage door opening standard residential heights are 7 7 6 8 header the header is ideally a minimum 12 wide micro laminated beam that spans the width of the garage door opening.
Rarely a steel or iron if very old house beam would be in there but is more common in solid brick or stone construction but unless the lintel is a substantial.