i want to reside a 25 yr old garage. the bottom of the 1/2" celotex sheathing sucked up some h2o over the years, and looked like this when i took off the old siding.
i've decided to cut off the bottom 2' all the way around and put on some pressure treated 1/2" OSB in it's place. i've noticed there is some water damage throughout the celotex...you know, a splotch here or there.
my q's are:
is my 'plan' the correct way the best overall way to do this job?
do i have to replace all boards that have water stain on them, or can i leave the partially (but still intact) stained boards up and re-side over them once i replace the lower pieces to seal up the bottom?
First off, if you haven't already done it, is to take care of the water problem. That old brown board really sucks up water and gets deformed when it is wet. With osb currently at $6 a sheet, I would probably remove all the brown board and do the bottom with treated ply like you said, and the rest with 7/16 osb.