The purpose of the pressure wash is to rinse away the chalky residue, removes dust, mildew and some loose paint; may be performed up to a month prior to painting. If the washer happens to miss something or could not reach something on the house, during the prep time, the painters will wipe down the house removing all cobwebs, nests, etc. No one has to be home for the pressure wash; we only need access to your back yard and to your water spigot. Please be sure that your animals are not loose. Although we love dogs, we do not want one of your pets escaping because we were not aware of them being there.