If you get the urge to paint, keep an eye on the weather forecast. Painting exteriors in the autumn can be done but you need to be careful.
Exterior products need to cure a little before being subjected to cold temperatures and moisture. Latex paint that feels dry to the touch can re-wet when dew settles on it causing it to streak or bleed out surfactants, a brown soapy substance that is in paint to keep it from foaming in the can. It’s best if the night time lows are above fifty degrees but 35 degrees and dry will not hurt most paints.
If you have to paint, remember to paint early. You can start applying paint as soon as the surface is dry and the temperature is above thirty-five degrees. All of California Paints and all of PPG Paint’s exterior latex paints can be applied if the temperature is above thirty-five degrees. California Paints has added a line to specifically address this weather, Malibu. Malibu develops an early moisture resistance that allows you to paint longer with less worry about impending rain or dew. With most paints you should stop three to four hours before sunset so that the paint has several hours of curing in the warm weather before the dew hits it. This doesn’t eliminate the possibility of re-wetting but we’ve found that, in most cases, the added drying time increases your chances of a good paint job in less than desirable conditions. With Malibu you should still allow 2 hours before rain or dew.
Standard painting practice is to never paint if rain is forecast in the next twenty-four hours and make sure that the surface is dry that you’re painting. Remember that bare wood absorbs a lot of moisture and you should let it dry several days before priming so that you’re not trapping moisture under the paint. Trapped moisture is a main contributor to peeling paint.
So, let’s review. Paint early, stop early and watch the weather. Nobody likes painting enough to want to do the job twice.