Last summer (2009) we applied two coats of an exterior latex water base deep red paint (clear coat base) to lightly textured, previously painted wood siding on our house. The house had been spray painted very pale green about 10 years ago. The surface was in good condition and only

We painted our ‘dutch barn’ style house red last summer. Since then white blotches or stains have appeared in several areas. Some stains are almost ‘chalky’ texture. The stains seem to come and go occasionally. What caused the white stains?