How to Prep Walls for Painting

You've completed your wall repairs and now it's time for final preparations.

In this video you'll get guidance on preparing walls for painting. Get tips on the best ways to remove dirt and grime from your wall's surface, how to apply painter's tape to trim, how to brush on and roll on your coat of primer, and how to caulk any gaps you may have between your walls and trim. Your walls will be in tip top shape for painting after following these simple instructions.

1. Prep

Remove all loose paint and patched any holes or cracks in your walls.

2. Washing Walls

Cleaning walls and trim will remove grime, cobwebs, dust and stains that can prevent your paint from adhering.

Use a mixture of lukewarm water and mild soap, gently rubbing in a circular motion.

Rinse your walls using a slightly damp cellulose sponge.

Tip: Check that your walls and trim are thoroughly dry before applying painter’s tape to your trim.

3. Taping

Use longer pieces of tape rather than several shorter pieces. Minimizing the possibilities for gaps in your tape helps ensure your paint won’t sneak through.

Start in a corner, pressing to the trim in small sections as you go.

Using a clean putty knife, press the tape’s edges to the trim so your tape sticks firmly. This will help ensure you get a nice, even paint line.

4. Drop Cloths

Use one or more drop cloths to protect your flooring and furniture from paint drips while painting walls.

Canvas drop cloths are the most durable and the fabric works to absorb paint drips and spills. Reuse over and over.

Plastic and paper drop cloths cost less but tend to slide when you walk on them, so use painter’s tape to secure the edges to the floor.

Tip: Painting your room in a darker color? It’s best to use a tinted primer rather than white.

5. Priming

Primer isn’t just to cover up old paint and imperfections. Starting off with a primer base helps you get the true color and sheen you’re looking for from your paint. Plus it provides a layer specially formulated to protect your topcoat.

Using a 2" or 2½" angled bristle brush, paint a narrow strip of primer all along your trim and the inside corners of your room.

Prime the remainder of your wall with a roller. Use a ⅜" to ½" nap thickness for smooth surfaces. Use a ½" to 1" nap thickness for rough or stippled surfaces.

Tip: Check out the caulk label for dry time so you know how long to wait before you can paint.

6. Caulking

Bothered by small gaps between your molding and wall? Fill them with an acrylic caulk after priming the wall and trim surface.

Some caulks are paintable but others are not, so make sure you read the label.

Use the little hole in your caulk gun handle to cut the tip of the tube at a 45-degree angle.

Carefully pierce the inner seal inside the tip using the seal puncture tool found on most caulk guns.

Load the tube into your caulk gun and squeeze out a small amount to start the flow. Have a damp cotton rag handy to clean up excess.

Start in one corner of your room, point the caulk tube tip into the crack, and gently squeeze an even flow of caulk along the crack.

Wet your finger and use it to smooth out and remove excess amounts of caulk. Have a damp cloth handy to wipe your finger clean.


Click here for a printable materials checklist and step-by-step guidance.


Have More Questions? Ask the experts at your neighborhood Sherwin-Williams store and be fully prepared to achieve beautiful painting results.

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