Sliding patio door replacement

[dlminehart]

I'm remodeling my family room, which has an 8' (actually 94") sliding patio door leading to my deck. The door is a non-standard height: 79" rather than the usual 80". It has a 9" header immediately over the door, with 5" studs separating the header from the 2x4s at the top of the wall. This sliding door, and a similar but 2' narrower one in the adjoining dining room, plus a bathroom door to the deck, are the three openings on this first story rear wall. In the second story wall above, there are a couple small bathroom windows and a large sliding bedroom window.

The ceiling of the family room has joists that run parallel to the wall containing the sliding door. Can I interpret that to mean that the wall with the slider is a non-bearing wall? Or does this depend on how the joists in the attic, above the second story, are arranged? I.e., if the attic joists were perpendicular to those above the first floor, would both rear and side walls then be bearing walls? I've yet to check the joists in the attic (hate going up there!) but plan to do so.

If I assume that the rear wall with slider is a bearing wall, how would I go about raising the slider's header by 1 inch? Seems that I'd somehow have to add external or internal (to the room) supports to the 2x4s at the top of that rear wall while I had the header out. How is this typically done?

If I were confident the wall is NOT a bearing wall, can I just remove and raise the header without any interim supports?

[jlm]

I think it's wise to pretty much treat any exterior wall as load-bearing, no matter how the joists run.

I haven't done any work on exterior walls, but I recently enlarged a doorway in an interior load-bearing wall, and the way we did it was to build a temporary support wall parallel to the existing wall. This "wall" was framed just like a normal wall - sole plate, studs, and double top plate - except the second top plate wasn't nailed in, and the whole thing was just a bit shorter than needed. We put it up plumb, then slid the loose top plate in at the top and used shims between the two top plates to wedge it very tightly and take some of the load off the existing wall.

Once the load is supported by the new "wall", you can do whatever you need with the load-bearing wall. Once you're all done, just knock out the shims and take down the temporary support. It wasn't necessary in my case, since the ceiling in this house is a mess, but if you're worried about scuffing up the ceiling, you might use a piece of carpet or something to keep from damaging the ceiling.

In my case, the floor was a concrete slab, but if you've got a basement, you probably want to make sure the temporary supports go perpendicular to the floor joists.