Attached is door header design I did recently where a client with a two story house over a full walkout basement wanted to replace a standard patio door in the basement that provides access to the inground pool with a 16 foot patio door. The door contractor realized this header was more than a couple 2x12s and wanted an engineer to design the header.
The technical issues that needed to be addressed were:
- Calculating the load on the beam from the two stories and the roof required a triple 18" LVL beam.
- The beam deflection can not transfer any loading to the door.
- A larger header beam would require cutting 5 1/2" off the ends of the existing floor joists and supporting the existing floor joists on the side of the new header beam with joist hangers.
- Designing temporary support for the floor joists above until the new header was in place. But before you can cut these joists to fit the header you have to support the exterior wall loads for the 1st floor, 2nd floor and roof truss. Because once the joists are cut the only support for the exterior wall is the 3/4 subfloor. The contractor could have built a second temporary support wall above the one in the basement, but damaging the floor tile and ceiling texture on the first floor was something he wanted to avoid. So a temporary double 2x12x18’ ledger was bolted on the outside wall allowing 4x4 posts to be used for support.
This was an unusual case which required more time and detailed drawings so my fee was $1600. I wanted inspectors to get a feel how complex adding a larger door can be.
Exterior 16 Foot Door Header_Redacted.pdf (120.7 KB)