b'Making theChoice:Leaving theOld Frame InLeaving the OldFrame in PlaceFor Aluminum Windows that have been mounted to theunderlying sheathing through a nailing fin, it is possible toleave the old frame in and not disturb the siding.First, you need to remove the operating sash and the fixedsash, Usually this is easy to do unless the fixed glass isglazed directly into the window framing. If so, tape the glasswith duct tape to help hold the glass together in case youneed to use force to get it out.Once the glass panels are safely removed, used a reciprocat-ing saw to cut through the vertical meeting stile as close tothe header and sill frame members as possible.Once the center meeting stile is removed, apply a beddingsealant and place the wide flange window against the oldframe and seat the sealant.Trim the interior as needed. Be sure to address where theflange of the new window sits against the old header tomake sure water is diverted out and over the new windowrather than behind it as it cascades down the side of theexterior wall.It is imperative that the top of the new window is sealed toprevent cascading water from penetrating behind the exteri-or flange and into the cavity between the window and theopening.Window Fitters Guide to Window Installation712020 AWDI, LLC Do not reproduce without permission'