I just bought a 1984 21' Sunrader and I can feel (and hear) under the carpet that the subfloor at about mid-point is rotted and will need replacing. I'll probably replace the entire subfloor since I'm going to gut the interior (excluding the bathroom). I assume the existing subfloor is particle board (heavy!) and was wondering for those that have replaced the subfloor what material they replaced it with? Maybe something lighter than particle/wafer board?
Thanks