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How to Clean Walls Before Painting?

How to Clean Walls Before Painting - BSM Inc

A poorly done paint job is painfully easy to spot. More often than not, the uneven lines and drips that are the hallmarks of a poorly executed job result from skipping a necessary step: cleaning and prepping. Before you even crack open a paint bucket, perhaps the most important step to ensuring that your walls end up beautifully smooth and drip-free is setting aside a day to ensure that your space is adequately prepped.


Before you begin, you should ensure that you have the following materials for Clean Walls Before Painting :

  • Wash bucket
  • Drop Cloths / Plastic Sheets
  • Mild dishwashing soap
  • Cellulose sponge
  • Painter’s tape
  • Flexible putty knife
  • Primer
  • Plastic paint container
  • Roller pan/tray
  • Paint stir sticks
  • 2-inch to 3-inch angled sash paint brush
  • Paint roller
  • Paint roller covers
  • ⅜ -inch to ½-inch nap thickness for smooth surfaces.
  • ½-inch to 1-inch nap thickness for rough or stippled surfaces
  • Paint roller extension pole
  • Paint rags
  • Ladder
  • Acrylic caulk
  • Caulk gun

Prep the Room

The last thing you want is to get paint on your vintage heirloom your grandmother gave you or damage your favorite sofa in the living room. That’s why before you begin the process of painting, the first step is to cover any furniture in your room that you’re going to be painting with protective tarps, such as a lightweight plastic sheet or drop cloth.

Better yet, altogether remove any furniture you want to protect from the room. If you don’t have enough space to move the furniture out, push everything into the center of the room to avoid damage.


Wash the Wall

The first step to preparing a wall is to clean the wall you are going to paint. You should wash the walls and trim before you begin to remove any grime, dirt, and cobwebs that might prevent your paint from adhering smoothly to the walls. A vacuum or damp towel will do best to dust and wash your walls before painting.

Clean your walls by creating a solution out of lukewarm water and mild soap, and use a sponge to buff the walls in circular motions. For tackling more dirty surfaces, such as kitchen walls that may have been exposed to grime or oil, you can mix grease-cutting detergent into your solution to remove tough stains. Then, you can go in with a cellulose sponge and water to remove residual dirt. Finish up and pat dry with a damp cloth.


Repair Drywall Holes and Nicks

Prepping drywall? If your drywall has any holes, you’re going to want to patch them up before applying paint. You can fill the holes with pre-mixed spackling paste or mix it yourself with an “easy-sand” joint compound, which is available at home centers and hardware stores at 25-lb bags of powder that you can easily mix with water.

Mark Trouble Areas

At first glance, a wall can appear to have no imperfections. However, a little exposure to harsh afternoon sun can reveal a myriad of minor wall flaws that become glaringly obvious. 

That’s why it’s important to go through a process called “raking,” or identifying problem areas with a light on your walls before you begin painting. Draw all the curtains, turn off the lights, shine a light on your wall, move it across the surface, and mark all problem areas. Stick a piece of tape wherever you encounter a blemish or crack so that later you can go in with a joint compound to correct it. Tape is preferable to circling problem areas because a pen can stain the paint.

Sand Surfaces

To apply a perfect coat of paint to your newly cleaned wall, you might want to use some sandpaper to remove the burrs and rough spots. Sanding can also level out spackling compound and drywall joint compound patches, flatten ridges around nail holes, and dull out uneven surfaces. 

Make sure that any flakes from sanding or scraping are removed before you begin painting. Sand the walls from top to bottom to smooth out the surface sufficiently. You can use an electric sander or just sheer muscle power with a piece of sandpaper stapled to a sanding block.

Apply Painter’s Tape

First, you should grab a roll of painter’s tape to mask off your moldings, windows, and doors. You should also remove outlet and light switch covers to protect them from paint drips. Next, protect the sconces and wall trim with your painter’s tape. Use more extended pieces of tape instead of shorter ones because this will make them easier to peel off when your paint job is done.

It will also minimize the probability of paint sneaking through when you use long pieces instead of several short pieces. Finally, use a clean putty knife to push your tape into the trim to ensure that the tape sticks firmly and produces a clean paint line.


Prime and Paint the Ceiling First

If you are painting a ceiling in your room, you should first tackle the walls. Priming is a crucial step to ensure that you’ll get the most out of your paint. Primers create a smooth surface for your paint to lock onto, smooths out imperfections, and provides a uniform finish. Use a roller to apply a latex primer to your ceiling, which will seal the wall and prevent mold. In addition, a high-quality primer can hide imperfections on the walls, such as holes or stains.

If your ceiling has much smoke damage and stains, use an oil-based primer to smooth over blemishes. If you’re painting on new drywall, use a water-based primer. Finally, if you’re painting your wall a darker color, it’s best to use a tinted primer instead of white.


Seal Up any Torn Paper

Drywall paper can easily get torn up, be it from friction from moving chairs around, an energetic toddler flinging a toy at the wall, or a remote control thrown across the room. Coating paint over unaddressed torn paper will produce a fuzzy texture that is less than desirable. Make sure to paint over the torn paper areas with primer to avoid this. 

First, cut away any loose paper. Then, seal the exposed drywall with a stain-blocking primer. After the primer is dried, sand away the edges. Then, apply a thin layer of joint compound to the gouge and feather it out with the wall to achieve a seamless look. After you use the joint compound, make sure to apply primer before you paint to prevent flashing, a phenomenon where the joint compound absorbs the paint and dulls the finish.



Those pesky gaps between the molding and a wall can ruin the look of an otherwise excellent paint job. Caulking covers a wide range of sins and prevents the penetration of moisture vapor into the walls. 

Cracks show up the best after priming, so you should go ahead and prime your wall first. You want to make sure that you caulk all the joints between trim and walls before painting. However, check your label before you begin because some caulks are paintable, and some are not. Have a damp rag ready to perfect any spillages. Aim your caulk gun at the cracks, and apply an even stream of caulk to fill your gaps. 

Although prepping a wall for paint is not exciting, it’s an important step that should not be neglected. It’s the extra step that separates a good paint job from a great paint job. If you follow the steps outlined in this article, you’ll be well on your way to that perfect finish!

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