Moisture barrier installation question for replacement siding

kooshball

I will be replacing my ABTCO siding soon on one wall of my home with Hardi or Nichiha cement board. I plan to strip off any trim boards that are rotting and replace them as needed but by doing this the good ones will remain and will not get the moisture barrier under them; is this ok? Do I need to strip all trim and corner boards so that I can wrap the home with a continuous layer of moisture barrier?

Also, I have what appears to be some type of asphalt (black) sheathing behind my siding (not plywood), should I still use a house wrap with this or will it block off the breathabilty?


Thanks

Gary in WA

Do I need to strip all trim and corner boards so that I can wrap the home with a continuous layer of moisture barrier?-------- YES! The corners are a very weak link: 1. The starting and ending place for most applications (the barrier is seldom folded up 5 times to maintain a waterproof joint there). 2. The corner boards are usually wood that opens and closes joints with season changes. The caulking /siding/trim joint opens and fails there (looks good from the surface).

"Also, I have what appears to be some type of asphalt (black) sheathing behind my siding (not plywood), should I still use a house wrap with this or will it block off the breathabilty?" --- probably 30 or 15# asphalt paper (the real deal unlike today's 15# that weighs 7-1/2#). Read my other answer to breatability issues.
You spent a lot of money and research on the job, yet leave corners on......
Be safe, Gary

__________________