New generation of RV are coming with aluminium frames, but there is lot of misleading about it, as my Fleetwood had big sign on it "aluminium frame" but turned out aluminium was just basic skeleton and lot of wood to rot.
Recently I bought 16 years old Lance. When the camper has some lack of engineering, looks like PO at some point had all the trim removed and resealed with butyl tape. The excess squeeze out, turn black and look ugly, but camper has no dryrot, although I bought it in AZ where is dry climate.
So if you want camper to last 20 years I think you have 2 main choices
1. keep it under a roof
2. remove and reseal all the trim outside.
