Green board paper peeling off in shower--fix versus replace?

[Steve Lansdowne]

A few square inches of the covering paper on the green board that covers about the top 2 feet of the wall above the ceramic tile in my home's shower has pulled away from the gypsum core. (House was well-built in 1952.) This has occurred in a few places, with the overall area affected sitting just above the tile. There is no mold or mildew, simply a very old shower whose textured green board is covered with oil-based paint. I noticed this as I was scraping off the cracked 15 year old paint in preparation for repainting.

Can I seal the exposed gypsum board prior to repainting, rather than replacing the entire piece of green board? (Replacement would likely affect the top row of tiles, which I imagine are set in 1/2" of cement, since they are not flush with the wall, and this seems like a potential major job which I'd like to avoid.) How would I best make this repair without removing the green board? The gypsum itself is solid and smooth. I'm thinking of oil-based exterior Kilz, then a thin coat of water resistant (exterior) joint compound (or exterior spackle?), more Kilz, and finally oil based paint. Does this sound reasonable?

[Rich]

It sounds very reasonable. One thing to think about is longevity of what's there. The damage could be from something you aren't seeing.. like possibly no vapor barrier.

[mfinley919]

Green board from 1952?

Yeah like Rich says, this problem is crying out and doing everything but slapping you in the face saying: "Look at me! Look at me!, There is a big problem here and I am warning you about it!"

For this to be happening there is probably something out of wack. Lousy ventilation, or even no ventilation. That peeling is a symptom of the problem, not the problem itself. Just cosmetically fixing it isn't serving your best interests.