If you live in a painted wood house, it will definitely require a fresh coat at some point, whether next week or next year. There are advantages and disadvantages to both brush and spray painting; knowing the strengths and weaknesses of each method helps decide which method or even a combination of each is right for you.
Spray Painting Advantages
Spray painting a house, once you're comfortable with the technique, takes significantly less time than painting it entirely with a paintbrush. The spray can reach into cracks and nooks between boards more easily than jabbing at these small areas with brush bristles. Assorted nozzles for the paint sprayer result in different spray patterns, such as a wide fan which covers a large area with each pass.
Spray Painting Disadvantages
Painting a house with a paint sprayer is similar in some ways to using a spray can. A windy day renders the sprayer useless, as most of the paint will end up anywhere other than where you want it to go. A sprayer's mist is so fine that as much as 40 percent of the paint spray may drift through the air rather than landing on the house, where it's intended. Using a sprayer requires practice; assembling and maintaining it also require significant effort compared to painting a house with brushes.
Brush Painting Advantages
Paint applied with a brush goes on thicker than paint applied with a sprayer, and covers flaws on the home's exterior a bit better. Brush-painting can be done even on a windy day without worrying about paint loss or over-spraying. Brushes can handle fine details and house trim in contrasting colors, whereas painting such areas with a sprayer may be impractical, as a significant amount of time would be spent masking areas around the details. A paintbrush is much easier to clean, use and maintain than a paint sprayer and is far less expensive.
Brush Painting Disadvantages
Painting a house with a brush takes significantly longer than with a sprayer, which also means greater potential for fatigue. If painting an entire house alone, using a brush may make the task seem nearly impossible, taking many days, weeks or months to complete, depending on your availability. It's also more fatiguing to paint areas overhead, such as a roof overhang, with a brush, as you'll have to apply pressure while painting, compared to simply waving a sprayer wand at the project area.