Most interior wall and ceiling painting can be facilitated by using a roller. There are certain steps you must take to make your project run smoothly and efficiently and give you the finished product you're looking for.
First you must select the size of roller and cover. In most cases 7" and 9" rollers and covers appropriate. There are wider sizes available (14" and 18") but in general they are for coating floors and roofs. They are also much heavier to use than the standard 7" or 9" roller.
Prepare your roller cover by pre-conditioning. If you are going to be using a latex paint you will want to pre-condition with tap water. Spin the roller to remove excess water. This is a vital step because it will prevent paint from adhering to the fiber of the roller rather than releasing the paint onto the desired surface.
If you will be using an oil-based paint, first lubricate the cover with the same solvent you will be using to thin the paint. Use this same process if you are using a mohair cover. The only exception to the pre-conditioning rule is when using a lambskin cover. The natural oils in lambskin act in the same manner as pre-conditioning.
Now you must fill your tray. The tray should never be more than 1/3 full. Load the entire surface of your roller with paint - make sure it covers all areas of the roller. Just roll the roller slowly down the tray into the paint and back. After repeating several times, the roller will have absorbed paint on all sides. Using a tray grid will help prevent overloading.
Always paint walls from the top down and work from unpainted sections into painted sections. To get started, paint a large "W" in a space approximately 3ft. x 3ft. Start filling in the spaces, being careful to paint from unpainted sections to painted sections and blend into the strokes of your "W". Repeat this same process with new area you start.
Clean up is much easier if you clean up immediately after you've completed your project. It is always best to consult manufacturer's suggestions for cleaning instructions. Remove the cover from the frame of the roller. In general, latex and water-based paints are best cleaned up with water. Oil-based paints, enamels and varnish should be cleaned with mineral spirits or turpentine.
String your roller on a dowel to help it to dry. Be careful not to stand the roller on its end, or lay it on the nap since this will distort the roller for future use.
Be sure it is thoroughly dry and then store it away in a dust free area. Your roller will be good as new and ready for your next project.