Siding Stains are the yellow staining that accumulates under the eaves of a home, usually associated with white vinyl or aluminum sided houses, but can also affect other colors in a lesser manner. It is a culmination of dirt, smoke residue, and various environmental factors that settle in on the siding. Usually you notice it in the upper parts of a house because the soffits of the home prevent it from being rinsed regularly by rain. It is a tricky thing to clean because just a pressure washer alone(no matter the temperature or the intensity of the pressure) cannot remove this on it's own. It requires a special chemical mixture to be applied after a basic softwash and then very thorough rinsing. This is not a very expensive restoration service, but it has a small additional cost due to price of special chemical needed and the fact that the home will need to be thoroughly washed 2 or more times to complete the whole process.