Painting walls and ceilings with a roller is not complicated, but it can require a certain touch to avoid roller marks, especially when using finishes like semi-gloss and eggshell. To sidestep this problem, consider using flat latex paint for your walls and ceilings. The easiest, most foolproof way to get a professional looking finish is to use flat latex, instead of a shiny finish, for these surfaces. Flat latex is very forgiving and will not show marks from repeated rolling and brush touch-ups.
If you must use a shiny finish on walls and ceilings you should always roll in complete strokes from one barrier to another, such as from a baseboard to a ceiling, without stopping. This will minimize the possibility of leaving roller marks. On ceilings and high walls this may be a problem because of the difficulty rolling complete strokes. So if at all possible, use flat in these situations for the best results.
Use a one gallon or larger paint tray. Stir the paint or shake the can to mix all the pigment and then fill the tray one half to 3|4 full. Have a brush handy and use it to clean the rim of the can. With the paint at a manageable level in the can you can use it as a pail and cut in the corners with the brush before rolling.
When filling the roller don't go too deeply into the paint or place the nap directly in the pool, to try and soak it up. This will create runs and roller marks from excess paint on the edges and frame. Fill the roller by turning it back and forth into the edge of the pool several times until the nap is saturated. If the nap becomes saturated on one side, causing the roller to resists turning, hold it stationary with a putty knife or screwdriver and force the dry part into the edge of the pool until it is evenly saturated and the roller turns freely.
Work the paint into the nap by turning it repeatedly on the tray until it moves freely and leaves a smooth coat on the tray. With the paint evenly distributed in the roller, attach an extension pole and begin rolling, starting at one corner of the room.
Begin rolling the ceiling a few inches away from the wall just outside the brushed paint. Roll about a 5 foot strip moving parallel with the wall. At the end of your stroke roll back in the opposite direction, working out away from the wall. Roll back and forth like this, moving out a little farther with each stroke, leaving a zigzag pattern with the paint.
Stop a few feet out and then roll back toward the wall, filling in the missed space as you go. When you reach the wall go slowly to avoid bumping it with the roller. Roll repeatedly, back and forth over the whole area several times to even out the coat and flatten any roller marks.
Refill the roller and start a new swath of paint a few inches from the last. Roll a few feet farther out toward the center of the ceiling, leaving a zigzag pattern.
Roll back the other way and into the first section of paint, filling the gaps as you go. Roll back and forth gently until the coat is smooth with no roller marks and the two sections blend together seamlessly.
Continue in this way until the ceiling is finished. Blend the rolled paint into the brush work around light fixtures and at walls, using a lightly filled roller. Roll repeatedly, but gently until the two areas are blended into a smooth, blended coat.
Let latex flat paint dry for an hour or more and apply a second coat, if necessary. Let eggshell, semi and high-gloss latex dry three or four hours and let alkyd or oil dry 12 to 24 hours between coats.
Roll the walls starting a few inches away from the corner and a little down from the ceiling. Roll parallel with the wall corner, down to the baseboard and then back up to the ceiling, without stopping. Go slowly as you reach the ceiling to avoid bumping it. Roll back down to the baseboard and then up again, leaving a W pattern with the paint.
Stop a couple feet out from the corner and roll back the other way to fill in the missed space. Go slowly when you reach the corner to avoid bumping the other wall. Roll over the whole swath lightly and repeatedly, from floor to ceiling, to blend the coat and smooth out any roller marks. Work out from the corner in this way to apply a swath of paint, a couple of feet wide, from floor to ceiling.
Refill the roller and start a second swath, a few inches from the first. Begin a little down the wall from the ceiling and roll in complete strokes, working out a couple of feet more into the wall.
Roll back toward the corner and into the first swath of paint to blend the two into a smooth coat. Roll repeatedly in complete strokes to smooth out any roller marks and cover in an even coat. Continue in this manner to finish painting the wall. If one coat won't cover completely, let it dry and do a second coat using the same method of brushing first and then rolling.