I have several windows with the seal between the two panes of glass buckling. Have been given a myriad of reasons why and starting to have doubts with several of the contractors who have checked it out, pictures attached. We have no moisture or water issues. The big concern is the exterior wood has started to rot in these two east-facing windows. The rest of the 68 windows all look pretty good.

Have been told the buckling is due to the sun, windows in question face east, not west, which is the hottest exposure. 2. due to a seal broken and allowing water and moisture into the window and causing the wood to rot, though we have not had rain or moisture from the transoms and there is no clouding between the two lanes of glass indicating a broken seal.

A few contractors have suggested replacing both the double hung and transoms the same time. Others have suggested just the transoms since the windows are fine, though in perhaps ten years they may been replacing, maybe not.

i might add, the double hung windows are Wenco, now owned by Jeld Wen and the transoms are another company so both were installed by th builder independent of the other. They are not one unit.

Attaching a few pictures and would appreciate input on whether or not to replace just the transoms or both double hung windows and transoms.

Considering Pella 450 or 850, which would be aluminum clad on the exterior, wood inside. We have wood exterior now, which raises another question. I have selected a color that is a good match for the siding and existing trim around the windows, but will it look ok if the transom has the aluminum clad and the lower double hung window has the wood trim? These two windows are in the rear of the house and face our side, which is private. I guess my concern is the aesthetics and if the clad above the wood trim will be a noticeable difference.

appreciate any and all suggestions!