Painted pine trim may not last as long as you might think. We’ve seen cases where pine trim has started to rot in only 4 years. This was not always the case; the quality of the wood has deteriorated. Many antique homes have the original trim. Our own home has the original pine trim from 1986 and it is holding up well. It is very important to stain or paint all six sides to prevent moisture from getting into the wood. Do not forget to touch up the areas where you made a cut. This will help a lot. Composites and aluminum, although expensive, could provide more value these days. See the photo of our model solarium. We used all aluminum and composite to keep it as maintenance free as possible.