We are in the midst of a major addition to an existing older home. We are noticing that on a few of the exterior walls of the existing house, they are covered with bubbles under the paint. I assume this is due to moisture being trapped by the old plaster (There was some rain right after we ripped off all the eaves). The builder doesn't seem too worried about it, but I'm not sure. It may be the thinking that "once the moisture is gone the bubbles will get sucked back in," I'm not buying, since it's not happening! I'm afraid I'm looking at replastering a bunch of walls that I had no intention of touching at this point. I'd love some feedback.