Bob, I am trying to repair a crack/ moisture problem in my daughters ceiling that has had radiant heat in since 1954..we no longer use the heat as of 1997. What kinds of levels are involved? how far do i need to go? I think i've scraped off a textured plaster level but am not sure now, it seems like there is a sandy textured level under it. I have looked on the web to find out what exactly is all involved and how best to repair, as you can imagine all my rooms have cracks and will need repaired, but this one seemed to have had moisture damage also. thanks for any input rick simpkins