I live in Michigan and it appears to be a rather frigid winter this year. We are remodeling a mst. Bath and have demo'd to the studs in the shower and the tub deck surround area. Let me add that 3 walls in this room are exterior. Just happened to pull back the faced R-19 insulation to discover that the insulation was damp and the sheathing was frosted and wet. What shall we do? Don't want to have issues down the road after investing all this time and money into this project. Thank you