Mold/ wet basement window sill

[Larisa Van Valkenburg]

Hi,

we fixed the basement window sill a year ago, it was ruined by water leaking from outside as we thought.   I had handyman work on the slab to raise it. The basement window is on the north and irs quite damp outside in the corner there.

Today I saw black mold on that nice window sill that has not been painted yet. I had a contractor to look at it today and he told me to rip it off and to insert some plastic to prevent it from getting wet. 

I do not want to redo the window sill for hundreds of times.  I would appreciate all your thoughts and guesses. And the best way to fix it once and for all,thanks

[Steve R.]

1 the slope out outside might no be enough
2 it is a single glass window with a storm glass outside. Most likely there is too much cold is coming through window and the moisture is from condensation

I would replace the window with a vinyl jamb, make the window a little smaller height wise so it would be raised at least 1" above where it starts right now, do aluminum capping around it a silicone the hell out of it outside