How to Paint a Room With Primer

Clean the walls with dishwashing detergent if they are heavily soiled. Rinse them with a large sponge and clean water, and let them dry.

Mask the trim if you're not painting it. Use painter's tape, not masking tape, to get a tight seal so primer and paint won't seep underneath. Unless you have a steady hand, mask the ceiling as well unless you plan on priming and painting it. Lay down dropcloths or plastic sheeting to protect the floor.

Repair the surface as necessary. Apply vinyl spackling paste with a putty knife to fill in gouges, holes and cracks. Wait until it's dry, then sand smooth. Use acoustic spray texture if you have textured walls. It's available in small cans and will match most commonly-applied textures. Allow it to dry--it can be primed within 30 minutes.

Pour the primer into a 5-gallon bucket and stir it. Some primers have a lot of thick sediment that settles to the bottom. Stir that up with the stir stick and pour the primer back and forth from the can to the bucket a few times until the consistency is smooth. Pour the primer from the 5-gallon bucket into a roller tray, or put a roller grid into the bucket.

Apply one coat of primer, using a roller and brush. When painting the finish coats, paint with the brush first and follow up with the roller, to avoid visible brush marks. It doesn't matter whether you brush or roll first when you are priming since it will be covered up when you've finished the job. Allow the primer to dry before painting.