Originally Posted by goransons
...As far as ribs conducting heat/cold etc I'm sure they do, when we get snow and have the heat on in the trailer, after some time on the outside you can see the ribs only (not where the fiberglass is) but we've never noticed much difference on the inside.
In humid climates or very cold weather, the inside skin adjacent to the ribs have been seen to sweat or have a frost line (from breath moisture). So the ribs really do conduct quite a bit. That's one reason that it's not so productive to do "special" insulation, unless you also tape all the ribs and stringers with foam tape--don't if even doing that makes the "special" insultation, eg, bubble, worth it. I think the local improvement in R-value gets lost in the noise due to the ribs, leaks, etc.