My well meaning but short-cut minded friend applied new skip trowel drywall over sheetrock where there had previously been paper in a bathroom. He then applied a coat of semi-gloss latex enamel. I was upset when I heard that he had skipped the primer. Aside from the obvious repercussions like the uneven finish appearance of the paint, now it is failing and wrinkling, especially in the areas where there is a lot of moisture, like above the shower enclosure. What do I do to remedy this? Does the entire surface of the drywall need to be removed, re-done, primed and painted? It’s a small bathroom, and is on my summer project list! Thanks!