Am restoring an old (100+/-) house. Have plastered walls downstairs and they are looking pretty good. Placed drywalll over ceilings, so they are great. Now it is time to restore upstairs. What a mess. The walls are very damaged and the ceilings are some kind of texture plaster or something over old plaster. Looks like polystepal. My questions are: Will I do the upstairs walls the same as the downstairs or because they are so badly damaged should they be replaced? Do I have to take the texturing off the ceilings or is there a way to make them smooth enought to paint? Also, some of the ceilings are those white tiles that look like pressed paper. Can I plaster over them? Don't want to start on this project until I have a firm plan in mind.