I'm in the process of rebuilding a FEMA Salem trailer and have a question about roof vents. The TT I have has 2 roof vents that were originally used as vents for the bathroom sink and bathtub. PVC pipe was used down inside walls connecting the vents to the plumbing. I've relocated the bathroom so I won't be using the existing vent holes. It was suggested to me that I leave the 2 roof vents in place without the PVC pipe to allow the air space between the ceiling and roof to breath. That air space of course will have insulation but there's always air movement even in confined spaces such as that small air space. I was thinking that leaving those vents in to allow any condensation to escape wouldn't be a bad idea. Thoughts and opinions?