I’m in the middle of insulating our attached garage. It will not be heated except for a small utility closet.

2×4 walls consist of the following:

1/2 Plywood (interior)
R15 Rockwool
1/2 Plywood
Siga Mavjest 500 SA
Hardie Lap Siding (no rain screen)

I don’t plan on painting the interior plywood. I might seal/coat it with something simple.

Should I be concerned about moisture getting into the walls? Would it be smart to put something like Intello on? Or would it be fine on its own?

I was thinking about filling gaps with putty before sealing. But there will be exposed screws and I want to keep the panels somewhat easily removable for future services/updates (most things come into the house from W garage wall).

The ceiling is drywall. The attic floor will air sealed