Cleaning Guides

How to Clean Walls Before Painting

If you’ve landed our blog post first, that’s for a good reason. We’ve prepped thousands of walls before painting them. And we’ll teach you how to do it. In this article, the Fantastic Services team will explain how to clean walls before painting.

Table of Contents:

So, if you

  • fancy getting rid of this yucky and outdated peach colour in your kitchen,
  • found that your tenants had ruined your wall with puke and wine after a birthday bash,
  • moved to a place that has not “seen” a paintbrush for decades,
  • want to just wash off a dirty but otherwise, perfectly fine wall without the intent to repaint it,

then, what you’ll learn in a minute may well save the day.

Tools you need

  • Vacuum cleaner;
  • Putty knife (in some cases);
  • Polyfilla (if there are cracks and holes);
  • Fine-grit sandpaper;
  • Bucket and a sponge;
  • Washing-up liquid;

How to clean walls before painting

Time needed: 3 hours.

If you don’t make the effort and do it right, any painting job afterwards, no matter how good you are, will look shoddy and sad. Old stains will show through in a week or so. Specks of dust or tiny flakes of old paint will fail the smooth look and feel of the surface. So, this is how to wash walls before painting.

  1. Vacuum the wall

    A powerful Karcher-type vacuum cleaner is great to use not only to remove dust and cobwebs, but also flaky old paint. Always vacuum the wall surface with the soft attachment only if there is no visible peeling paint. This way you won’t risk chipping away by accident any of the paint. But if there are flakes here and there, remove the soft attachment to achieve better contact with the surface and a more powerful suction effect.

  2. Remove stubborn patches of old paint 

    Your putty knife can come handy (or any other bladed tool, for that matter) if you need to lift patches of old paint. Gently place the blade at one end of the half-peeled patch of paint and work the tool at a very slight angle without using too much force. Then, use again your vacuum cleaner, as described above, to help with the paint removal process. Or in other words, alternate using both the knife and the vacuum cleaner until the wall is free of stubborn patches of old paint.

  3. Fill in cracks and holes 

    Another important step of preparing your wall before painting that you may or may not need to do is making the surface as smooth as possible. This means – no cracks or holes on the wall. Get a Polyfilla type of filler and carefully apply a small amount over the hole to even out the surface. Note that the drying time is about an hour or so if the layer is no more than 5-6mm thick.

  4. Give the wall a gentle sanding

    Again, you will only need to do this if you’ve had to go through step 2 and step 3. Use fine-grit sandpaper (360-grit will do) and smooth out the surface with circular motions. Don’t apply too much force.

  5. Vacuum again

    Well, if you need to remove imperfections by sanding the wall, this will create dust. Grab your vacuum cleaner again and go over the surface with the soft attachment of the machine.

  6. Mix up your cleaning solution

    Now comes the cleaning of your wall. Prepare a general-purpose cleaning solution by mixing warm water and washing-up liquid in a bucket. Providing that the wall doesn’t have any hard-to-remove stains, your cleaning mixture should do the job.

  7. Wash the wall with a sponge

    Use a sponge to wash the wall. Make sure that you wring it out well to avoid streaks. Experts advise to start from the bottom upwards and clean the surface, using circular motions. Be careful when you climb up a ladder or stand on a chair, as a nasty fall is the last thing you need. When you’re done, have a little rest and repeat the process with clean water only. You can clean your wall this way even if you have no intentions to repaint it.

  8. Leave the surface to air-dry

    Our recommendation is to leave the damp wall to dry by itself, even if you’re dying to get down to painting as soon as possible. Just open a window to speed up the process and be patient. Alternatively, turn on a fan or a heater, depending on the season. You see, if you use a towel to dry the wall, you may end up with a surface, covered in fluff, should the rag is made of the “wrong” material. A cloth or towel that sheds fibre, which can easily stick to your freshly-washed wall, is simply something that you don’t want to happen, right? If you hope to get that smooth paint finish afterwards, that is.

You may also like:
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Now you know how to wash the walls before painting. But what if you stumble upon greasy stains? Or mould? It’s simple, use the tips below:

Wall stain removal tips

Accidents happen that can end up on your wall in the form of stains. And if you don’t make the effort to remove them properly beforehand, you’ll risk some of these spots and marks (grease, mould, red wine, for instance) showing up eventually through the new coat of paint.

  • Mould. Mix 3 parts water and 1 part bleach in a spray bottle and apply over the mouldy spots. Leave for a few minutes and then scrub with a brush. To reinforce the mould removing process and kill the spores for good so that the problem doesn’t reappear, you can also spray some undiluted white vinegar. Leave the substance to work its magic deep into the wall surface. There’s no need to wash the vinegar and don’t worry about any lingering smell, as it will eventually evaporate and disappear.
  • Red wine. You can try getting rid of red wine stains on your wall by applying some hydrogen peroxide (3%) on a clean cloth and then, work the stain gently with it. Repeat, if needed.
  • Grease. Greasy stains (and coffee/tea marks, as well as specs of dried blood, for that matter) can be removed with a cloth dipped in undiluted dishwashing liquid. When done cleaning the stain, wash it with a sponge and clean water only. Always wring out the sponge well to prevent streaks.
If you need to use the above stain removal methods and have no plans to re-decorate your wall, you may still have to retouch the cleaned patches with paint of the original colour and brand.

Hire a professional to do the job for you

Cleaning the walls before painting them can be a straightforward task, of course, which you can do yourself. But if the surface needs prepping to get rid of various wall imperfections, then, you should best leave the job to a professional painter and decorator. 

The same applies even when it comes to just washing your perfectly even wall, especially if it suffers from some hard-to-remove staining. An experienced cleaning expert simply has the know-how of wall spot cleaning, and the skills and products to remove stubborn stains.

The good news is that Fantastic Services can help you in both cases, as we provide stellar cleaning services and interior renovation solutions. Just get in touch with us and share what you need to be done! We’ll send the right professional for the job at hand.

Visit the main website for price rates on our professional painters and decorators!


  • Always test the stain removal solution on an inconspicuous place on your wall, first. This could be behind a piece of furniture or artwork.
  • Don’t forget to wear a dust mask if the prep-work before painting your wall requires sanding, as well.
  • Bathroom or kitchen wall renovation is best left to a professional, as wall surfaces in these rooms are more susceptible to mould issues and staining, which means that the walls may need expert preparation work before being painted.


And this is how to clean walls before painting. Do you think we missed something? Got an interesting detail you’d like to share? Just use the comment section below! 

Image source: VGstockstudio/

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