How to clean walls before painting

+18 votes
asked Apr 19, 2018 in Home & Garden by AbeP9701145 (270 points)
edited May 25, 2019
I don't have any problem with painting, but cleaning is something I hate with passion. I have always read that it is important to clean my walls before painting them, especially the interiors. But must I do this before painting? Or is there an alternative to this requirement? If I must clean first, how to clean walls before painting?

2 Answers

+23 votes
answered Feb 12, 2019 by FelipaLowell (370 points)
edited Jun 26, 2019

In some cases you don’t actually need to clean your wall. Here is how you judge.

Get a very dry white piece of clothing and use it to clean the wall. Make sure you run it the whole length of your wall. You can skip the washing part if the color range when you turn over the clothing is from white to very light-grey.

If not, then you have to clean your walls. But how to clean walls before painting? Do you really need to use TSP (Tris odium Phosphate)? I have found many alternatives for ya.

Interior Painting Preparation Without the TSP

If you want to skip the aspect of TSP cleaning, you must at least follow the instructions below:

  • Get rid of the big things: use a vacuum or broom to get rid of the cobwebs and dust bunnies.
  • Baseboards and trim: use a fairly wet piece of cloth and clean up the upper parts of the doors, window trims and the baseboards. These are places that normally accumulate large collection of dusts. Getting them cleaned up will enable the painters tape to stick.
  • Vacuum: With the hair-like connection on a shop or home vacuum, clean the floorings closest to the walls.

Alternative to Washing: Pole Sanding

Most professional painters will not wash your walls before painting, unless you give them extra tip to do so. But most times, they pole sand flat surfaces using fine-grit sandpaper. This removes all junk and sticky dirt, deglossess surfaces, and brings most stipple down. To learn pole sanding, check the video below:

When You Should Use TSP for Washing

In addition to most essential painting collections, you should keep your TSP handy. TSP can be used in the following cases:

  • In your kitchen areas with accumulated grease.
  • In your bathroom areas with soap scum. Or in bathrooms with lots of misted sprays such as hairspray.
  • In areas in your home that get lots of bodily contact (door jambs, near door handles, etc.).
  • In rooms that receive large amounts of oil-soluble markings (For example, the Crayons found in children's rooms).
  • On all walls, above your heating registers.
+9 votes
answered Feb 24, 2019 by TrenaNott37 (360 points)
edited Jul 3, 2019

Good question ‘how to clean walls before painting’! You need to wipe of several things from your walls before painting commences!

Washing Your Walls

The fact that surface dirt can lead to very poor adhesion makes using a light soap to wash off soiled surfaces very necessary. These surfaces include those that are often touched, or has some oily deposits from cooking. Make sure the soap does not leave any residue behind.

Wash all trims and doors, especially where they are often handled. Wipe all surfaces using a damp cloth once the surfaces are clean enough. Make sure the wall dries before painting commences.

Getting Rid of Pen, Water Stains, and Crayon

Preparing a wall for painting requires using liquid soap to get rid of all marks made by crayons, pens, water stains, etc. Use a neat wet cloth for wiping. If any mark remains after the wiping exercise, use Fresh Start or Moore's QD 30 to stop the finished coatings from bleeding.

Dull Glossy Areas

To make sure there is effective adhesion, use sandpaper and sand all glossy surfaces. Remove all sanding dust. Clean all surfaces using vacuum cleaning and wipe using a tack piece of cloth.


Examine the floors, walls, and all ceiling surfaces for traces of nail holes, cracks, or any such surface flaws. Rake out all large plaster opening or hanging particles in your ceilings and walls using a putty knife.

Press some spackling compounds firmly into all crevices using the putty knife and smoothen it out until the spackling compound and the surfaces are of the same flush.

To fill up mitered open connections and window or door trim that is separate from your walls, press the compound firmly into all crevices, and smoothen it using your finger. Leave it to dry before sanding lightly.

Apply the patching compound twice for the best results since patching compounds shrink when they dry.

Getting Rid Of Loose Paint

Remove scaling or loose paint using a putty knife. When you get rid of paints from ceilings and walls, fill the paint edges to make sure surfaces are smooth. This will blend the two paint levels to make the edges unnoticeable after re-coating. When getting rid of paint from doors, trim, or sash, make use of a fine sandpaper for sanding the whole surface.

So above are how to clean walls before painting and what you should remove from your walls. Hope everything goes on well with your repainting!

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