window deflection

[PSUengineer1]

Thank you for reviewing my question. I have pictures attached for reference.
I am trying to figure out why one window in a three window side by side configuration appears to be leaning downward at the top and away from the two other windows. There are no visible cracks in any of the window glass. Small cracks are visible in the drywall wall surface above the windows. The top of the molding around the left most window (viewing from interior) is out of level by as much as 0.5 degrees. The owner of the home reports that the interior blinds are closed 99 percent of the time so they are not sure when they noticed that the window appeared to be leaning.
Rotting wood framing is visible at the interior base molding of the middle window. The exterior ground slope was measured as 0.0 percent adjacent to the windows and elevated levels of moisture were detected in the wood framing below the vicinity of the rotted base molding of the middle window. No elevated levels of moisture detected in the basement wall framing (block basement walls covered by drywall). The first floor wood joists run perpendicular to the basement wall below the subject window.
No elevated levels of moisture were detected in the exterior wood siding above the window so I am ruling out water intrusion through the wood siding and water intrusion from a roof leak. Do you think that based on the poor surface water drainage that moisture could have been introduced into the exterior of the wood framing member spanning between the basement windows situated below the subject window? I am questioning whether or not the trim that is out of level at the top of the window was just installed that way? I think I need a contractor to start “peeling” it away so I can investigate further, what do you think?
It is possible that jack studs of a previously smaller opening could have been cut to facilitate installation of a larger window configuration. The lean is possibly the result of a lack of installation of a sufficinely stron header above the window configuration, what do you think?

 

[EngineeringEric]

0.5 Degrees is level if measured with a bubble level. If i had to guess, it was installed that way. the window opening probably was not flashed properly or the fins not sealed or bottom fin was taped. if the bottom of the window was taped or flashed to the building wrap it would hold water instead of flowing down as designed. Perfect example of more sealing is sometimes a bad thing.

I would tear off the exterior facade on one side and mainly look at the top and bottom of the penetration. I wouldn't be concerned with the out of plumb honestly. look up the manuf. literature and see what their tolerance is, some windows are good for a few degrees off plumb.

or, just tell the HO to replace the window and have a professional look at the surrounding framing while the window is removed.