Durability of Al-Clad over Wood Interior Windows

Lynne Murray
6 days ago


I am replacing Marvin AL-Clad/wood frames/sashes, triple pane windows due to water infiltration and rot of the cladded wood. These windows were installed in 1982 and have been problematic. The spacers failed early. Marvin replaced the sashes but the problem continued. Now the window frames are rotted, the glazing collapsed and the house has taken on water due to windows being compromised. The windows are casement, awning or fixed typical of a shed-style home of early 80's.

I was planning to replace with Andersen E Series (AL-clad/wood) but now I am second guessing myself as I do not want to repeat the (probable?) mistake that my father did in 1982 when he built the home. So, I am researching all fiberglass frames such as Marvin, Pella and Andersen composite Fibrex 100 series as I am really concerned about moisture being trapped behind the AL-clad (or FG or vinyl clad over wood) and repeating the same problems with the cladded wood. I recognized that the non-permeable cladding is possibly trapping condensate/water/humidity from the house and rotting the wood frame from the inside out. I cannot afford all wood nor do I prefer vinyl.

I realize that the problematic windows was about how the windows were built and that it was not the type of wood selected (pine) but what materials and how they were used was the problem; and finally not the failed spacers (which did not help but just hastened the rotting process). I realized that the wood preservatives are better and the frames are cladded in reverse from the time these 1982 Marvin Al-clad/wood windows were installed in this house. Yet, I only have once to do this right or I too will live in a leaky house.

So, my question to those contractors/window installers/designers who are familiar with how windows are presently built and install them frequently, are these same concerns founded in today's windows? Has the manufacturing been improved that the cladded wood does not rot due to lack of moisture vapor through the cladding material?

My question to you is given the climate of VA has the AL-clad wood windows (regardless of company) improved in the 40 years or will I face the same problems and should look to singular material window frame to ensure that I can get 20 years use out of the replacement windows and have a viable window into the third decade of use? Or am I smoking wacky weed to even think it is possible for today's windows to have three decades of viable use?

Thank you for your assistance.

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