Chalking is identified by the fine chalky powder that forms on the surface of a paint film. Although some chalking is a normal way in which paints self-clean when exposed to the sun and rain, excessive chalking can indicate paint failure. In dry arid climates where there is little rain, chalking can become excessive. Chalking is actually the paint pigment released by the paint binders that have been broken down by exposure to the weather. Chalking is especially common with very light-colored flat paints, especially lesser quality oil-based paints containing high levels of pigment extenders. When chalking gets severe, it may run off and stain the surrounding construction.
Walls should be wet down before getting scrubbed, then washed with a gallon of water mixed with 1 cup chlorine bleach and 1 cup of either a concentrated, phosphate-free cleaner, such as a trisodium phosphate (TSP) substitute, or Jomax House Cleaner. Working in sections, from the bottom to the top, will avoid streaks. Be sure to rinse walls well before the solution dries. Wood siding and trim should be ready to paint after a day or two of dry weather.
I am quoting labor costs to paint a neighbor’s house and garage with a total of 1876SF and trying to get up to date on costs and labor hours. While reading your article I see average quantities of paint needed for trim, labor hours and costs depending on square footage, also added costs depending on window types, etc. However when I use the calculator, the labor cost lists the trim as “extra” and the labor for 2 coats of paint on the body to rolled and brushed.