Since it's under the final Rubber Roofing Dicor product yet to be applied, I feel OK with this thin but smooth sheeting, for surfacing material. WHY? Well, because what I have added, is, an addition to, not a replacement of. Adding insulation and a minimal layer of framing addes a few pounds but much, in the way of insulation and believe me... I would not do this for insulation value UNLESS I already had the old roofing off and had this opportunity!
[No original wood is any better and probably has lesser glues, so this should be perfect.] I have read on other sites of using 3/8"-1/2" wood, but from what I can decifer, they are using that on larger rigs and for Primary Roofing. (I am Doubling this roof/sandwiching an EXTRA layer of Foam Board, and not just replacing the old damaged wood sheeting.)
So far these last steps are working out really nicely.
We squared out the aft roof,
rather than deal with the old rounded edge that was certainly a culprit for leaks, as it would be difficult for a mfgr., owner or re-builder to seal the seams here with any certainty of success.
Straight corners/edges make things somewhat easier to work with and that seems to be where the newer Motor Homes have gone to within their designs...so; I will also!
Having added One Inch of material to the roof,
the Front Edge adds a bit of a challenge. I'm zero-ing in on this, with some extra effort to make a smooth flowing, extremely well sealed edge. NOTHING will leak HERE! This, I guarantee will last longer than anything on this rig. Of course, more to come, but for now, you see I'm dealing with a One Inch added height and it's squared off.. more later.