Thanks for the quick response. I have seen the sand paint, but I don't think that's what I have. It almost looks like the whole ceiling was skim-coated, then textured with a brush or similar device. Although when I look at the cracks, it does not seem that there is that much compound/plaster on the drywall. Anyway, I like your idea about the plywood for strength. I guess I will have to play around a bit to get the texture right, unless anyone else has suggestions.