Hi all!- Skipping the intro, straight to it…

Split-level house built in 1964, sometime after then but before 71, a large, upper level, covered porch (25x13.5) was added to the backside of the house (no permits). The roof was modified to include covering the porch area, the ceiling of the porch is constructed entirely of vented vinyl soffit.

There is nothing under the soffit separating the air above from the porch air below.

A short time after the porch construction (also possibly before or around 71) an addition was constructed under the porch. (also not permitted) The ceiling in the addition is constructed of drop ceiling tiles.

Fast forward to 2012, patio enclosures removed the railings from the porch perimeter and installed glass panels and windows, enclosing the entire porch area. 7 panels are sliding window panels and there is 1 sliding glass door, the rest are stationary panels.

Fast forward to today.

The enclosed area can barely be used since the attic is venting into it, which makes it either very hot or very cold, no inbetween and also causes chaos throughout the house with the hvac system.

The entire add-on is slowly shifting away from the original structure, this can be seen by the cracks in the plaster of the exterior wall among other clues.

The weight of the glass panels is too much for the addition below to handle, the addition’s sliding door can barely open and close anymore because of the weight.

Finally, the floor of the porch is very weak on one half. We determined that there were steel beams installed, but only 2. One is a vertical beam pole and the other is a horizontal beam that runs the entire wall to wall distance in the center of the addition length. The vertical beam pole is hidden inside the one wall in the addition that creates two rooms, however, it is not center positioned, so the weight is not evenly distributed.

Interior room width measurements are room A-8’3” then separating wall with steel pole inside then room B with a 13’ stretch.

Go figure the larger half is the side with weakness and floor shaking on the porch even if a small child walks on the floor.

So to my question, with all the issues mentioned above, plus a few more not mentioned, also no other support beams, sister joists, nothing else is in place and we just partially removed some drop ceiling and the joists appear to only be 6-8” thick, I can see the bottom of the plywood, doesn’t appear to be any tar or rubber roofing or anything from before the porch was enclosed, none of the joists are any exact measurement of distance apart, they range from 14”-15-3/4”. I have already cut and secured some 2x4’s with heavy duty screws throughout some weak spots just for now until I figure out exactly how i want to take care of this whole situation. Back to my question…

I want to know, what is the cheapest and easiest route to go here? For all issues mentioned and without fully tearing it down. I wouldnt mind leaving joists exposed, i would need alternate suggestions, like foamboard in place of insulation, other sistering options, porch ceiling solutions, concerns with cracking

stucco and the weight of glass, other concerns for other things or hazards i may not have found yet. Thanks in advance!