Celotex/Masonite behind Cedar Shakes

shub

While having a contractor remove the shakes from a deteriorated side of my new home, I noticed that behind each course of red cedar shakes, there is a masonite/fiberboard type material, lapped in similar fashion as the shakes.

After noticing this, I started looking at the underside of all the intact sections of siding on the house, and noticed that the fiberboard is visible, about at a depth about 1/2 inch less than the exposure of the shake on top of it.

Three questions:

1. Does this material pose a moisture threat?
2. I noticed that the exposed edge of the fiberboard behind the shakes is not painted. Are painters deliberately not painting this area, so the house can breathe? Or when I re-paint the house, should I "smoosh" paint up and under there to help lock out moisture infiltration?
3. When I have the shakes replaced, will they appear flatter (lack depth) not having the fiberboard behind each course? Should I have some alternate material installed behind each course as well?

Tom Struble

i'ts normal,don't try to seal it and use an under-course if that's the look you want