I have found a lot of good information in Breaktime and have used it – many thanks. But – I have an unanswered question. In the 1880’s farmhouse style house, we would like a tin ceiling in the kitchen. Do I tear the lath and plaster off the ceiling and then put up the 3/8″ plywood? or just plywood over? It’s not good plaster. We tore off the walls because they were crumbling so badly. Some of the ceiling has already fallen down. Opinions?