How to paint the outside of your house - Continued

If you want to apply water based latex paint to an older house that had been protected with an oil-based paint, no problem.  Wash and prepare the surface well, and before starting to paint, apply an oil-based primer made to work with latex paint.  Never try to apply oil-based paint over latex.  This will cause adhesion problems.

Always stick with compatible systems when doing a two-coat paint job.  Use a primer and a topcoat paint that are made to work together.  The easiest way to do this is to stick with the same manufacturer for both products.  If you mix brands, there is a chance the additives may clash and cause your good work to fail.  To avoid intercoat peeling problems in a season or two, be sure to apply the top coat of paint within a week or two of applying the primer.  Never prime new work in the fall and then come back in the spring to finish the job.  The primer will get dirty and also will develop compounds on its surface that will resist bonding with the topcoat. 

Paint exterior siding in hot dry weather, when the wood is as dry as possible.  Your paint will last longer.  Never paint on a cool surface that will be in hot direct sunlight in a few hours.  You will get temperature blisters or bubbles in the new paint.  Do not paint when the temperature is below fifty degrees.  You will risk poor bonding between coats and the chance of inner coat peeling down the road.  Never apply latex paint in the early morning before all the dew has lifted or in the evening of a cool spring or fall day.  You will risk streaking and discoloration as the fresh dew mixes with the water in the wet paint.