Often, especially with older homes, when you start to decorate the room, you may find that the plaster starts to come off the wall or is very rough. This can make it very difficult to get a smooth finish and you may feel that the only option is re plaster the walls. This can be extremely expensive and delay any decorating that you wanted to do.
If you do find that you have this issue to contend with then rather than forking out for a plaster you could try and use lining paper to line the walls. You can use this under wallpaper or to paint on. There are different thicknesses of lining paper so it is important that you choose the right one for your wall, depending on how bad they are. You also need to consider the paste that you are going to use as you will need to ensure it is right for the thickness of the paper. If you buy paste that you have to make yourself you will need to check on the packet about how much water is needed to make it the right consistency. This will add an extra step to your decorating but can save you a lot of money.