If it`s sunny you want to get the tfr washed off before it dries and don`t mix it too strong.I rinse the fascia with just water pressure,spray with tfr mix,wash it off once you see the dirt running and breaking down,then repeat the process again,it`s amazing how much crap comes off with minimal effort.The only downside is the tfr can leave the windows covered in white dots if you don`t swill them properly,also don`t have the pressure too high,get it so it is moveing the dirt and no more or you might flood the loft,plus the pole is harder to hold.When i get a real dirty one i wash half and show customer the difference.good luck. Dan