Painting the outside of your house can be overwhelming so let’s break it into manageable pieces. The first thing you need to do is clean the surface. Use 3 parts water & 1 part bleach in a pump up sprayer. Make sure to completely wet the surface, apply the bleach solution a couple times just to make sure the bleach has time to kill any mildew. Keep it wet about 10 to 15 minutes. If you have areas that are badly mildewed or areas that mildew frequently use Jomax House Cleaner and follow the directions on the label. You may need to scrub with a brush to remove dirt.
There is a lot of advertising going on about the new low VOC paints. Lets start with what VOC's (Volital Organic Content) are. Basically VOC's are what, other than water, evaporates into the air during the curing of the paint. These are usually solvents used during the manufacturing of the paint, and they help improve application characteristics. Many paint companies make a low VOC paint and some even make zero VOC products. However these terms only apply to the paint before it is tinted to your color.
With the ever changing temperatures we have been experiencing I thought it would be a good time to discuss the effects cool temperature has on paint. First you can get "surfactant leaching" which is when the wetting agents of the paint create a soapy discoloration on the paint films surface. This occurs when applying paint in cool temperatures or very high humidity, or exposing the paint film to these conditions before it is completely dry. This condition can usually be fixed by washing the surface with a mild detergent.
I am occasionally ask why the outside of my cabinet doors are lighter than the inside. The answer is usually because they were painted with an Alkyd or Oil base paint. Alkyd or oil based paints will darken or amber over time. Absence of light accelerates this process so areas that don't get exposed to light will darken quicker. Quite often touch ups that are light in color when first applied will blend in over time. Using a high quality Alkyd will help but not eliminate this condition.
In our area, where we are exposed to a lot of heat, humidity and ocean breezes, mildew can be a challenge. Mildew is an airborne spore that lands and stays on everything that isn't washed frequently. Contrary to some peoples belief paint does not cause mildew. Mildew grows on concrete, roofs, fences, cars and probably even us if we didn't bathe. When starting an exterior painting or staining project you must start with a clean surface. Use 3 parts water and 1 part bleach to remove existing mildew, and mildew spores are there even if you don't see them.