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.