For smoothing the edges of scraped spots here and there, you can wrap a piece of sandpaper around a wood block. For larger areas, it's less tiring and more effective to use an electric orbital sander. Move it up and down or back and forth across the surface to remove old paint and smooth rough edges at the same time. Don't use an electric disc sander or a belt sander. Both can leave swirls or dips in the wood that will show through a new coat of paint.
The last big decision is how to apply the paint. Most pros use paint sprayers because they're fast, but in inexperienced hands a high-powered sprayer can leave drips, thin coats, and a mist that may land on many things other than your siding. If you do hire a painter who uses a sprayer, make sure he is meticulous about removing, covering, or masking off everything in the area that might get hit with overspray: gutters, roofs, windows, shrubbery, walkways, cars—you name it.
With homeownership the family aspiration, Dad, a housepainter, always sought opportunities to work overtime. — Bill Cummings, BostonGlobe.com, "Dad taught me the art of negotiating when I was just a kid," 24 May 2018 At the outset, a Hanson housepainter embodies the relationship between three-dimensional art and life, fact and fiction. — Karen Wilkin, WSJ, "A Morbid, Engaging Body of Work," 26 Mar. 2018 Rosenthal was the youngest of six children of a Bronx housepainter who emigrated from Belarus. — Alex S. Jones, Town & Country, "Will the Rivalry Between the Washington Post and New York Times Save Journalism?," 9 Aug. 2017
Before the scrubdown, protect nearby plants by misting their leaves and saturating the surrounding soil with water, pulling them away from the house, and shrouding them in fabric drop cloths. (Plants will cook under plastic.) Lay more drop cloths along the base of the walls to collect any falling paint debris. 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.
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.
The time needed to complete an exterior paint job varies depending on the size of the home, the condition of your home’s exterior, the weather conditions and type of paint used on the job. An average project lasts 3-4 days, while a complex project may take a week or more. Additional time may be needed to fix loose or damaged siding or add primer to areas without coverage. Your painter will provide a timeline that explains how long the project will last and will schedule the job to avoid inclement weather.