Before you do any paint or prep work, be sure to protect the floor. Drop cloths made for paint work the best. They are heavy, so they stay in place better and stop the spills from leaking through. Some people use bed sheets but they are too thin and do not protect from spills. Plastic stops spills but can be too slippery and dangerous to work on.
Scrape any loose paint from the walls with a scraper. If it is a little tough to get off, it is probably OK to stay on the wall. Use a heavy grit sand paper (80 to 100) and sand all the surfaces you plan to paint. You can get sanding pads that mount to a pole to make the job easier. Sanding helps the new layer of paint stick to the old paint and gets rid of any high spots. You will need to patch where you have scraped off the loose paint using a spakling or drywall compound. You will need to patch any holes or dings as well. Let the spakling dry and sand with a fine grit sand paper or sanding pad. You may require more than one coat to get a flat finish, so reapply and sand as necessary. If you notice any gaps where the trim meets the wall, apply a paintable caulking and wipe excess away with a damp cloth.
Once everything has dried and has been sanded, you will need to prime the patched areas. You do not need to prime the entire area; just the patches. This is called "spot priming" . Some painters will use left over paint and spot prime the areas a couple times to seal them up but primer works best. If you are painting new drywall, then you will need to prime the entire area. Sometimes, it's better to prime drywall trice to be sure you have a nice seal before you do your finish coats.
Once you have everything spot primed and dry, it's time to roll on a first coat. Roll up and down and get as close to the baseboard and ceiling as possible. When applying new paint; start ahead of where you finished and back roll a bit before you start moving ahead again. Apply an even but heavy coat first coat. Latex paint will dry very quickly so you can usually get to the next step quickly. At this point you will patch any imperfections again. After the first coat is best because sometimes the new colour will show differently than the last colour. Once you are done patching and have sanded you must spot prime those areas with your finish colour to seal them. While you are waiting for the patches to dry, you can cut in all the areas you can't get with the roller. A 2 1/2" brush and a steady hand work best for cutting in. You can use painter's tape to help but it takes more time and can be expensive if you need a few rolls. There are "cut in" tools that you could use as well.
Once everything has dried and the cutting in is done I recommend giving everything a good sand again. This will get rid of any rough areas and help obtain a flat finish. Use 80 grit on a sanding pad to do this. Before you roll on your final coat you will want to cut in again. This way the brush strokes will be covered by the roller texture. Once the cutting in is done, apply an nice, even coat. The paint will be dry to the touch in a short time but may take up to a month before it is completely dry.
When choosing paint, you usually get what you pay for. Poor quality paints have more water in them, so you may have to do an extra coat. You don't need the highest priced paint either. Latex paints should be filtered before you use them. You will need a filter and an empty can to filter your paint. This helps remove all the little chunks that harden in the can during storage that get mixed in when you or the paint store mixes it up. Buy a quality, lint free roller. Thicker rollers hold more paint but add more texture to the walls. Holding more paint speeds things up because you do not have to keep applying paint in your paint tray.
These tips should help with your next project and remember that practice makes perfect. Professional painters work for years at the trade before they can do top notch work very quickly. It may take you more time but you can make your next paint project look like a pro did it!
By Brent Darlington