New construction walls are generally made of drywall, also known as sheetrock. Nail holes, seams and other trouble spots in the drywall are covered with tape and a thin layer of joint compound. Ideally, the areas with joint compound should be smooth and even, but the quality often varies according to the contractor’s skill. For best results, inspect all areas of the drywall and make corrections as needed before you begin painting.
Fill in dents, holes, dings or other imperfections in the drywall with joint compound or spackling compound. Apply the compound with a putty knife and let it dry according to package directions.
Use a block sander or palm sander and 120-grit sandpaper to sand your repairs smooth. If the existing seams or repairs are thick or uneven, sand them down as well. Wear a dust mask during the sanding process to avoid inhaling particles.
Use a microfiber tack cloth to remove sanding dust. Go over the entire wall, not just the areas that you sanded, to remove any dust left over from the installation. You can hold the cloth in your hand or wrap it around the attachment at the end of any long pole, such as a painting pad or sponge mop.
Mask trim pieces with painters’ tape. Take care to ensure that the tape exactly meets the trim edge without overlapping onto the wall.
Use a small paintbrush to “cut in” a combination drywall sealer and primer around the trim. Use smooth, even strokes. Finish an entire section, such as the area along a whole trim piece, before taking a break.
Pour the drywall sealer and primer combination into a paint tray. Dip a roller into the sealer-primer and roll out the excess in the tray. Roll the mixture onto the wall using a wide, sweeping “W” motion. Overlap each stroke slightly to ensure smooth, even coverage. Finish the whole wall before taking a break.
Allow the wall to dry thoroughly overnight before painting.