Can You Wallpaper Over Walls That Aren't Perfectly Smooth?

Thicker, textured and heavily patterned papers are more forgiving of small flaws than thin, plain or glossy ones. Light colours and strong side lighting make bumps and seams more visible. Lining paper hung beneath can smooth small irregularities. What no paper can hide is loose, crumbling plaster, damp or large cracks, because those will keep moving or showing through.

You can usually paper over painted walls if the paint is sound. Glossy paint needs a light sanding or a suitable primer so the paste can grip, and flaking or peeling paint needs to be scraped and made good first. New plaster needs to be sealed so it doesn't soak up the paste. A bad, flaking base will take the wallpaper off with it when it fails.

It's tempting to leave old wallpaper up, but it's usually a mistake. Damp paste can loosen the old layer, seams show through the new paper, and pattern and texture can telegraph through. The better route is to strip it, wash off the paste and repair the wall. If you have several layers or vinyl paper, strip them carefully and check what's behind before you plan the job.

Cracks and holes should be filled and sanded flat. Bumps, such as old filler lumps or nibs of plaster, should be sanded back, because they show as ridges under paper. Surfaces that are still rough after repair can be skimmed or lined, depending on how much needs smoothing out. A little time here saves a lot of frustration at the seams.

Lining paper is a plain paper hung horizontally before the main wallpaper, and it's a standard trick for older walls. It covers hairline cracks, evens out small bumps and gives a uniform surface that the paste grips well. Hung properly, it also reduces the risk of seams opening on the finished paper. For heavily damaged walls, though, lining is not a substitute for repairing the plaster.

Older houses often have walls that aren't straight, corners that aren't square and ceilings that run slightly out of level. A good decorator allows for this by measuring and plumbing each drop instead of trusting the corner, and by planning where a pattern will break. Patterns with a large repeat or strong geometric lines show every misalignment, so they need more care on crooked walls, and they usually use more paper.

If your walls in Sutton Coldfield aren't perfect, choose a paper that suits them. Textured or heavier-weight papers, and busy or organic patterns, are kinder than plain, shiny or fine-striped ones. Ask for a sample and look at it on your wall in daylight and in the evening before you commit. Hand-printed and expensive papers are usually less forgiving, so they deserve the best preparation.

Some problems need fixing before any paper goes up. Damp, mould, crumbling plaster and wide, moving cracks should be investigated and dealt with, because paper only hides them for a while and the paste can make some of them worse. If you're not sure whether a patch is damp or just a stain, get it checked.

Good preparation adds time, from a day for a straightforward room to longer where walls need stripping, repairing and lining. It's worth it, because it's what makes a wallpapered wall look flat and the seams almost disappear. A quote that mentions the preparation, the lining and the type of paste is a good sign.