There is probably a flush beam there that is installed up in the roof or floor system. You just hanger the joists into the flush beam instead of resting them on top of a dropped beam.
Example of a flush beam
Definitely add a header there if it's a bearing wall and you're removing studs.
Why is there no header for the full height doorways?
I can think of two possibilities:
The wall is structurally unsound due to the missing support and if so, you should see some signs of that. (i.e. sagging, drywall cracking, etc.)
The wall is designed such that the unsupported span load is carried by the support on either side of the doorway opening.
The post looks reasonably adequate as it was originally built even by modern standards. If it wasn't you'd have seen disaster long ago, when it first started to decay.
To maintain the style detail I'd rebuild to match, using pressure-treated lumber. By doing so you eliminate the need to cut that notch and you end up with a more robust post. A single post ...
Structurally, there’s several issues: 1) Live Loads, 2) Dead Loads, 3) transfer of loads down to footings, 4) size of footings, 5) appearance.
1) The roof structure is designed for a Live Load (snow load) determined by your local building code. More than likely it’s 25 - 30 lbs. per square foot (psf), depending on where you’re located. A deck requires 40 ...
You have several issues to consider: 1) span of steel beam vrs. wood beam, 2) weight of steel beam vrs. wood beam, 3) connectors, 4) ease of connecting joists to wood beam vrs. steel beam, 5) ease of installing wood post vrs. steel post, 6) size of footing under posts.
1) Yes, steel beams can be smaller than wood beams when carrying the same load and ...
Yes, there is a chance that the wall could be a bearing wall.
You can determine if it’s a bearing wall by verifying if 1) the wall is near the middle of the house, 2) has roof joists resting on it, 3) has a beam or concrete footing under it, 4) has plywood, OSB board or double gypsum board on either side of the wall.
1) If the wall is near the middle of ...