Rotten Window Sil Relacement

craker

I'm relpaceing windows for a customer and 2 of the sils are rotten on the exterior of the house. Just wanted to see how others would handle the demo and replacement
thanks

house bldr

I'm a little confused, if you are replacing the windows why are the rotten sills an issue? Or are you just installing replacement window inserts? How rotten are they? The fix would depend on the situation.

troubleseeker

Like "house bldr" I'm asssuming that if you are concerned about the sill, you are installing replacement windows in the existing wood window frame. I do one of two choices depending on the replacement window being used. If the new window is thick enough to cover the step up in the old sill where the sash came down, I do not disturb the interior trim, but cut the old sill out along this step using a combination of circular saw and reciprocating saw. Then install a "ledger" for support under the seam, make a new piece to duplicate the old, bed it in polyurethane and slip into place, having also cut some "legs" to support it from below. The replacement unit will hide this seam and also protect it from the elements. If the new unit is not thick enough to cover this seam, I remove the interior apron, cut the entire sill out, and slip in a new duplicate.

craker

thanks guys. Sorry for the confusion,
yes , i'm talking about inserts