Bricked-up AC portal, how to treat and seal?
When we purchased our home 6 years ago we knew that there had been a built in AC unit in the living room wall. The previous owners removed the unit and bricked up the opening. They stuffed some insulation in the hole and nailed a thin wood panel over the inside. The wall was otherwise paneled.
On Monday I finally got tired of the paneling on the wall and ripped it down to the plaster. In the process I decided to remove the insulation in the hole and replace it with new, intending to patch the hole with drywall and seal it up permanently from the inside. I wanted to put new insulation in because the old appeared dirty and had evidence of mice.
While removing the insulation I discovered that a layer of canvas-textured vinyl/plastic was put between the insulation and the bricks. There was moisture and mold on the insulation and vinyl. I believe it is from condensation from the warm inside air contacting the cold surface of the vinyl. There appeared to be old water damage to the plaster wall, but I think it is probably from when the unit had been in the window. I have never detected leaking, moisture or a mildewy smell from this wall so I don't think it is a chronic rain related wetness that has caused the current mold on the vinyl.
I would like to remove the vinyl,clean out the hole then re-line, reseal, insulate and drywall it shut. It is a NNE wall...the outside being a bricked-up AC portal. Does anyone have any input into what sorts of barriers/liners I should use to avoid further condensation damage?