Painting can change the whole feel of a room. But slapping on fresh paint without prepping the walls for painting first? That’s a fast track to a rough, patchy finish.
If you're wondering how to prep walls for repainting or how to clean walls before painting, you're in the right place. A great result starts long before the paint roller hits the wall surface. Cleaning, patching, and smoothing things out may not be the fun part—if there is one—but it makes all the difference.
1. Start by clearing the area
Before you even think about a coat of paint, make space to work. Move as much furniture as you can out of the room. If something’s too big or too heavy, shift it to the center and cover it with a plastic drop cloth or an old sheet. Same goes for the floor—paint drips and dust from sanding are no joke.
Take down anything hanging on the walls: photos, shelves, artwork, curtain rods, hooks. Unscrew outlet covers and light switch plates. You’ll want full access to the entire wall surface, so don’t leave anything in the way. Prepping is easier (and faster) when you're not tripping over stuff.
Vacuum along the edges too. You don't want to be painting over dust bunnies.
2. Clean the walls
Clean surfaces are essential. Even clean-looking walls are usually dirtier than you think. Think about how often hands touch the wall near light switches or how cooking steam drifts around the kitchen. All that adds up over time. If you paint over dirty surface buildup, your paint won’t stick well—and it could start peeling or flaking.
Mix warm water with just a little mild dish soap or mild detergent and use a soft sponge or rag to gently clean the walls. Work in a circular motion. You’re not trying to soak them—just clean off grease, dust, or any marks. For stubborn stains, like kitchen walls near the stove or kids’ artwork zones, you can use a grease-cutting detergent or a bit of vinegar mixed with warm water. Rinse with clean water afterward to remove any soap or residue. Then give it time to fully dry.
3. Fix any damage
Once the walls are clean and dry, get in close and look for problems. Even tiny holes from old nails or pushpins will show through a fresh coat of paint. Run your hand across the entire wall surface—you’ll feel dents, bumps, or loose paint that might be hard to see.
Use spackling paste for small holes or cracks. For larger areas, like deeper gouges or long cracks, joint compound works better. Apply with a putty knife, smooth it out, and let it dry. Then sand it flat. If any old paint is peeling, flaking, or bubbling, scrape it off gently with a putty knife. Don’t try to just paint over it—new paint won’t hold, and you’ll see every flaw.
This part can feel tedious; however, it’s what separates a pro-looking job from a sloppy one. Think of it like ironing a shirt before an event—it just looks better when you have a smooth surface.
4. Sand the surface
Now it’s time to rough things up a bit—but just lightly. A quick sanding smooths out patched areas and dulls any gloss on the previous paint, which helps the new paint bond better. Use a sanding block or pole sander with fine-grit sandpaper. You don’t need to go wild—just enough to give a bit of grip to the surface before painting.
Once you’re done, wipe the walls with a damp cloth, damp sponge, or tack cloth to pick up all the loose dust. If you leave the dust, your paint might stick to that instead of the wall.
5. Tape and protect
Painter’s tape isn’t just for beginners. It keeps lines sharp and stops paint from bleeding onto trim, baseboards, or the ceiling. Apply it carefully along the edges, and press down firmly to seal it. Take your time—it’ll save you from having to fix mistakes later.
Double-check that your furniture is covered and the floor is protected from paint damage. Paint can drip or splatter even if you’re being careful.
6. Prime if needed
Not every wall needs primer, but you might be happy you did it. If you're painting over a dark color with a lighter one, primer helps you avoid needing extra coats. Same goes for walls with patchy spots, water stains, or areas you’ve repaired. Primer gives the surface an even base so your color goes on smoother and looks more consistent.
There are primers made for specific situations—stain-blocking, mold-resistant, or bonding primers for tricky surfaces. Ask at your paint store if you’re unsure, and they can point you to the right one.
FAQ
Do I need to wash every wall before painting?
Yes, even in low-traffic rooms painting prep is important. Dust, oils from your hands, and even air pollutants can settle on walls over time. A quick wipe-down with soapy water takes less time than fixing peeling later.
What if I skip primer—will the paint still work?
Sometimes, yes—but you’re taking a risk. Without primer, paint can go on blotchy or may need more coats to cover. If you’re covering a dark color, painting over patches, or working with a stained wall, skipping primer usually means you’ll notice it afterward. Think of primer as your insurance policy.
