The wallpaper also often leaves stains on the wall even after it is removed. Use Easysand or Durabond to repair the damaged finish coat unless you have a source of lime putty. Durabond is so hard it is very difficult to sand. Easysand is just that, easier to sand. Both are setting type joint compounds. You should use a bonding agent on the areas needing repair. It prevents the old plaster from absorbing water the new material needs to cure correctly. EUCO WELD is a good brand. If you cannot find plaster bonding agent use Elmer's white glue cut 50% with water. In either case, paint the agent on and wait for it to get tacky before putting the patch on top.

The way I figure wall paper Is to measure the height of the wall I want to cover....then measure down that number of inches on the roll...put a little pencil mark on the edge of that spot. Then search for the spot in the pattern that matches where you began at the beginning of the roll. the repeat can work for youas well as against you. When you find the place in the pattern that matches your first strip....again measure your needed length and put a mark. Repeat and that will tell you how many strips you will have to use. When going to the next roll....don't assume it will begin in the same spot on the pattern....check and again find your match and measure length. The only time you can use the "area of the wall" formula is if you have little or no waste due to match.

It can. You need good quality paper rated for a bathroom and very good ventilation (exhaust fan) that is used religiously! Better yet, put the fan on a humidistat and a timer.

I also grew up in NYC in a building complex built in the late 1920s. No central air and there was no vent in the bathroom, just a small window in the shower we would crack open for ventilation. My mother wallpapered the bathroom and it lasted many years but eventually began to peel at the edges. I do not know how she installed it but since she's an artist and the type to do everything correctly, I suspect she used the right techniques. The room definitely got steamy and moist on a daily basis as it was the primary bathroom for two teens.