Question: If a casement window is dripping water from the gap at the top
and the water gets between the inner and outer sash, is likely this would
cause the water to get behind the drywall and onto the floor?

Reason I'm asking is because, about 10 days ago after it rained, I had
water on the floor, and the drywall around the window corner was moist when
probing with moisture detector. (but the sill did not seem wet, and the
wallpaper was not wet) I wasn't in the room when the leak actually happened
though.

I don't know who makes these windows. They are aluminum clad with no
markings. The outer frame and outer sill is aluminum, but the inner sill
and inner part of the sash is wood.

Today it's rainy, I'm noticing that water is dripping from the gap at the
top, so now I'm SUSPECTING this is what happened last time (dripped from the
gap at top into the gab between inner and outer sash).

However, I'm afraid to conclude yet that this is the same exact thing that
happened 10 days though. Yesterday afternoon I tried squirting water from
an empty shampoo bottle directly into the gap at the top and I wasn't able
to get water to drip down the gap into the inside. And I suppose that maybe
my testing yesterday got the seal wet "primed it" to make drip through the
gap at the top this time. But I agree that the seal (V-type flap that fits
in the kerf on top of sash) has flattened out since I installed it last
spring. I will put some D-Seal rubber weather-strip underneath to give it
upward pressure. If water getting past the top seal is cause of what
happened 10 days ago then hopefully this will solve it.

Other thoughts:

I also notice that the association didn't caulk the gap where the siding
meets the top of the window. An engineer told me that there really should
not be caulk there because if water should ever get behind siding then it
would have no place to escape except inward. But I'm wondering if not
having it caulked there could also cause a leak if enough water gets into
that gap.

I tried to get the association to install drip caps last year, and the
property manager agreed to do it, but the workers did not want to take
siding off (even though they were replacing other wood that was rotted at
various locations). The lack of a drip cap doesn't seem to be helping
matters. These windows have a metal frame that sticks outward a little, but
no drip cap, and I'm told they have a flange underneath the siding. Do you
think I should have the association caulk the gap at the top where the
siding meets the window frame, even though an engineer says that's not the
right thing to do? Do you think I should push to have drip caps installed?

Thanks,

J.