WASH ANYTHING TO BE PAINTED!!Most contractors don't do this so demand it or do it yourself.I spent alot of time scraping on my house,it's beveled cedar,then I scrubed it with soap and water. I used Soilax because it doesn't leave a soap film,great stuff.Then I used good primer and paint, not cheap stuff.All latex.That was in 1992.I just painted again this year.