To paint a large section without leaving lap marks, roll the nearly dry roller in different directions along the dry edge, feathering out the paint as you go. After completing the entire length of the wall or ceiling, move to the next section and paint over the feathered edges. For the second coat, apply the paint in the opposite direction. This crisscrossing paint application sharply reduces (if not eliminates) lap marks.
As you scrape, you may find that the wood has turned gray or black in some areas. Check for rot by probing these areas with a nail. Spots that are discolored but firm are simply weathered. Weathered wood doesn’t hold paint very well, so sand away the gray surface. If you find soft areas, you’ve got rot. Small, shallow soft spots can be dug out and repaired with a two-part filler such as Minwax High Performance Wood Filler. But when rot is deep and widespread, it’s best to replace the entire piece of wood.
If the point of hiring a well established, experienced, reputable painting contractor is to secure the professionalism and trust suggested to be inherent with that choice, then I would EXPECT that professionalism and experience to include the ability to make the proper and correct calculations for labor and materials for a fixed price quote, and there should be NO reason for the contractor to put the cost burden of their miscalculation on the consumer.
House Painting Cost Exterior Broomfield Colorado