I'm not sure I understand your question ...Is the overlapped material underneath the plaster and lath or on the surface? If on the surface, and you don't think it's wall paper or NU-wall, then it may be canvas or some other attempt to either cover-up crumbling plaster or to provide a smooth surface for decorative painting. Why don't you want to remove it? (Other than it being a a nasty job to do.) Have you tried loosening it in a concealed area to assess how hard it would be to remove? You will always see those seams unless you sand them down, which might be a bigger pain than simpy removing the covering. A lot would depend on what your plaster is like underneath and whether you have rough or finish coat as a top surface. Perhaps your plaster is only rough coat and the paper was installed to make it easier to get a smooth finish. Another alternative would be to remove it and get a top coat put on. Or you could just slap a coat of paint over it and move on. As for cleaning, I wouldn't hesitate to use any cleaner, including TSP. Generally I prefer powdered products, rather liquids as I think the powders leave less residue. At the moment I am using up some green powdered laundry detergent, with out enzymes or optical brightening agents, and I like how it's going. (The stuff was a complete dud for laundry, though.) Some people wash with strong ammonia nd water solutions, but I hate that stuff. I have also used Lysol liquid detergents and been satisfied, but now prefer the powdered stuff. I have seen Spic and Span recommended, though I can't stand the smell. Another tactic is to use a steam cleaner. I have a Lady Bug, and while I'm not at all impressed with most of its uses, wall cleaning is something it does do well, though very slowly. (It can also steam wallpaper residue off, so try it first before doing a whole room if you choose to keep whatever is on your walls.) For primer, I have used Kilz and BIN, and both are very good but incredibly stinky to use (you really need to have an open window). Alisande's recommendation for using a good quality primer, is also good, particularly if you decide to just paint over the surface for now. With old houses knowing when to go whole hog and restore like crazy and when to just get things cleaned up and looking fine is the key to a happy life. Sounds like maybe just painting over your wall surfaces (after some cleaning) might be a good choice for you. Happy spring cleaning! Molly

For some reason washing surfaces before painting seems to have become unpopular and is not always done. ANY paint adheres better to a clean surface. If TSP is still available in your area (some places restrict it since it has a lot of phosphorous) it is still the best heavy duty cleaner for surfaces to be re-painted. It does take a wash and a separate rinse, but makes the surface clean to accept a new coat of paint.

I just painted a buttermilk yellow over a dark grey wall (don't ask) and for the first two walls I thought I should prime, but I still needed three coats of the yellow to cover (I paint mostly with a brush, it's only two coats with a roller). Then on the last wall I ran out of primer so used leftover beige paint... and it covered way better than the primer. I'm no expert, but my conclusion is that primer doesn't cover as well as paint. It seems to me that primer is meant to promote adhesion, not to colour things. In your situation the question is evenness, not coverage per se, so I could go over your splotches with the closest thing you have to the original wall colour. Then paint your final colour, probably two coats will do. KarinL

Should I prime the sheetrock and keep painting or do I need to peel off all the paint first? Absolutely do not peel off any more paint/paper. If I'm following the story, no you can't just paint over it. You're going to have to skim coat where the paper peeled off in order to even out the wall or else you're always going to see a line of demarcation between what is now essentially two different substrates - the part of the wall with paper and the part of the wall without. Paint is not primer. And primer does not act as a glue. I would hire a professional painter to fix this because there is an art to skim coating and repairing dry wall. If you want to DIY, take several pictures and go to a professional paint store - not a home store - and ask them to recommend process and products.