How Do You Get a Smooth Finish on Old, Damaged Walls?

Look at the walls in daylight from a low angle, and in the evening hold a torch flat against the surface. This shows hollow patches, ripples, hairline cracks, bulges and old repairs that you'd miss face on. Tap gently on any area that looks loose, and listen for a hollow sound. A wall that's merely marked is a very different job from a wall with crumbling plaster, and knowing which you have makes it much easier to understand a quote.

Hairline cracks and small holes are the easy end of repair. They're opened out slightly, filled with a suitable filler, left to dry, sanded flat and spot-primed, so the filler doesn't show through the paint as a dull patch. Cracks that keep coming back, especially wide or stepped ones, can point to movement in the building, and filling them won't solve that. If a crack is getting wider, have it looked at before you decorate.

Plaster that's come away from the wall sounds hollow when tapped and may crumble. Painting over it only hides the problem for a few weeks. Loose areas need to be cut back to sound plaster, repaired and made level before decorating. Older homes often have a mix of original plaster and later repairs, so it isn't unusual to find areas that need more than a quick fill.

Paint that's flaking or peeling needs to be scraped back to a firm edge, sanded to feather the edge and primed so the new coat doesn't lift it. Old wallpaper and layers of lining paper often need to be stripped first, and the walls washed to remove paste residue. Painting over wallpaper that's loosening is one of the quickest routes to a failed finish.

Be careful with older finishes. Very old layers of paint, particularly in homes built before the 1960s, can contain lead, and some textured coatings applied before the year 2000 contained asbestos. Neither is something to sand dry or scrape without thinking. If you're unsure what's on your walls or ceilings, or you're planning to sand or strip them yourself, get advice or testing first, and tell the decorator what you know about the age of the property.

When walls are too uneven or damaged to repair patch by patch, there are two bigger options. A skim coat of fresh plaster gives a new, flat surface but needs time to dry before painting. Lining paper is a lighter alternative that smooths minor irregularities and cracks and gives a good base for paint or wallpaper. Which is right depends on the condition of the wall, your budget and the finish you want, and it's best decided by someone who has seen the surface.

Primers seal the surface and help the topcoats bond. New plaster usually needs a thinned first coat, called a mist coat, so it doesn't soak up the paint. Stains from water, smoke or grease need a stain blocker, or they'll bleed through the new paint. For a damp stain, deal with the cause first. Painting over damp only hides it for a while, and it will come back.

A matt or very soft sheen is the most forgiving on imperfect walls, because it scatters light and hides small ripples. Silk and satin finishes look good on flat, well-prepared walls but show every flaw. If your walls in Sutton Coldfield are old and not perfectly flat, a good matt finish is often the best choice.

Good preparation takes time, and that's where much of the cost in a quote goes. It's not wasted. The preparation is what you're paying for when the walls still look smooth years later. Be wary of a quote that seems very low for a room with visible damage, because it may not allow for the repairs you can see.