I came across a bunch of 4" leftover polyiso bonded to 7/16 osb hunter panels for cheap and would like to use them on the exterior of a 1930's home rehab to add insulation value to the wall. The house needs resided anyway so I was thinking I could use these and attach them to the sheathing and then side over them. I have a couple problems I need help with however. Because of the way they manufacture them they are 47 3/4 x 95 1/2 actual dimensions. When used on roofing this really wouldn't matter as they are just butted and fastened to the roof sheathing. However if I want to attach them to vertical walls and hit the studs could I just adjust the panel to span the studs evenly which would result in a small gap between panels and then use a low expanding foam to fill that gap and tape the seam? Another problem is how would I do corners? Would I have to miter the panels so they meet up so the osb meets up or is there a way to just overlap one panel over the other and them form some sort of cap to cover the exposed end of the foam? Are there any other concerns for using these panels in this manner? I was planning to use 2" foamular but these panels are $25 each vs $30 for the foamular and these have a R value of 21.5 vs 10 for the foamular. The hunter panels also have the 7/16 nailbase so I can side right over it just like it was normal sheathing. Here is a link to the panels http://www.hpanels.com/images/stories/pdfs/lit_prod_color/english/H-Shield-NB.pdf Thanks ETA..... Also what would be your materials layup order? Sheathing/ house wrap/ 4" polyiso nailbase/siding or Sheathing/4"polyiso nailbase/house wrap/siding Also what about need of a rainscreen? (what exactly makes up a rain screen anyway?)