How to Add Texture to Already Painted Walls

Remove any wall hangings or art from the walls. Pull out all nails and screws to create a bare wall surface. Wash down the walls with a cleaning product that contains tri-sodium phosphate, or TSP. Let the solution remain on the walls for the amount of time recommended on the product label. Remove the solution, along with any loosened soil and grease, with a damp sponge. Let the walls dry completely.

Fill in any holes, dents and scratches with joint compound applied with a putty knife. Let the compound dry completely then sand the edges of the patched areas with fine-grade sandpaper to make them flush with the surrounding surface. Lightly buff the entire surface of the painted walls, removing just the outer sheen. Avoid using excessive pressure during sanding.

Wipe down the lightly sanded walls with a tack cloth to remove all traces of dust and other small particles. Tape off the edges of the walls and spread drop cloths below the area you intend to paint.

Use a paintbrush to apply primer to the walls around the edges and a roller with a smooth nap for the inside portion of the walls. Allow the primer coat to dry completely before continuing.

Apply texture paint to a small area of the wall that measures approximately 4 square feet. Use a thick-nap roller to provide even texture. Load the roller and apply the texture paint in a vertical motion, going over it a second time with the roller in a horizontal motion to create an even design. Paint the entire surface of the walls in this manner. Let the paint dry for the recommended amount of time on the product's label.

Use the thick-nap roller to apply your chosen color of paint on top of the texture paint. Apply a second coat of paint over the first coat to ensure even coverage.