Using home wallpaper is one of the easiest and quickest ways to created a new mood for your rooms. Wallpaper can cheer up a dull room, or change the atmosphere and style. It can reduce the apparent height of a tall room, or increase the perceived height of a low ceiling.
Another advantage of home wallpaper is to conceal flaws or unevenness in your walls. Older homes often suffer from this. It's a lot less expensive to line the walls with lining paper and apply a good wallpaper than completely replaster your walls.
Factors to consider
If your walls need to have a tough finish (lots of traffic on stairways, children rushing about, etc) then consider using a vinyl home wallpaper. These are more hard wearing than washable papers, because they are made from polyvinyl chloride with a paper backing rather than just a normal paper with a plastic coating.
Textured papers with embossed patterns are thicker than other papers, and are therefore better at concealing irregular surfaces.
Think of the effect you want
It's important to be sure of the effect a particular home wallpaper will have before you go and order a dozen or more rolls. If it's a large room which needs many rolls, it can be worth while buying just one roll and trying out a couple of lengths on your walls.
Try out a length of wallpaper with your window treatments, upholstery and carpets. Make sure all the elements 'fit' together as a total scheme.
The safest way is to 'build' all the elements of your scheme together, so get samples of wallpaper, carpets, fabrics etc. and make sure they all blend as you want them to. That way you don't end up with wallpaper which doesn't quite fit in with the rest of the room because it was an afterthought.
If you're using a patterned paper make sure it gives you the overall effect you want. Small patterns in particular can give a regular stripe or repeat effect when you hang two or more lengths together. Make sure you get the overall impression of a design.
How much paper do you need?
If you were to get quotes from two or three decorators, they would probably differ slightly on the number of rolls you need of your home wallpaper. One may say 12 rolls, the other two 13.
This doesn't mean they don't know their profession. There are different ways of estimating, and sometimes it comes down to personal choices.
An experienced decorator may get the job done quicker (and cheaper!) by using more rolls than you might order if you did it yourself. A quick method of estimating the quantity is to ignore all the doors, windows, fire surrounds, etc, and calculate based on the room measurements.
Example: your room is 4m square, wall height to be covered is 2.3m.Total width is 4m x 4m = 16m. Paper width is 53cms; so number of cuts is 16m ÷ 0.53m = 31 (30.19 rounded up). Assuming they are standard rolls of 10.05m length, you can get 4 cuts per roll (10.05 ÷ 2.3). So the number of rolls needed is 31 ÷ 4 = 8 (7.75 rounded up to 8).
Remember to allow a few inches top and bottom for your cuts, and it's always nice to have some paper left over in case of future damage by scratches, spilt drinks, dogs, etc. If your paper has a pattern repeat, then your cuts need to be a multiple of the repeat.
What you should know about dye batches
Wallpapers are made in batches - perhaps a few hundred or even a few thousand at a time. When manufacturers make a new batch, the dyes used have to be remixed, and may vary slightly from the previous batches.
This means that if you don't order enough paper, and the new roll(s) you need to finish the job come from a new batch, they may not match as well as you might hope.
Moral: make sure you order enough first time!
Preparation and application
Good preparation is the secret of good decorating.
Get your walls as smooth as you can. Remove all old paper and paint.
Some people think lining paper is an option, but my advice is to always use it. Lining paper is 'cross lined', that is, you apply it horizontally to the walls, and you can have a slight gap of a couple of mm between the cuts. Use the heaviest quality you can get. It really does make for a better finish for your home wallpaper.