I have been cleaning drives for a couple of years know with a powerwasher, and i used to have the same problems on yorkshire stone flags or indian stone.and also when u use too much pressure the stone breaks up and the cement around the outsides of the flags break up, and then you get unhappy customers.so one day i was at this big farm where i clean windows, and i seen the farmer using hypoclorate on his flags. and he swore by it. so i seaked where to buy it from and tryed the method out myself.
[
b]method[/b]
I put the chemical in a watering can, and sprinkle on the flags. I then use a big stiff brush to to make sure it is all over.Wear protective clothing and gloves and goggles.if not it will burn your skin.
I tend to leave these jobs for when it is due to rain as the chemical needs time to work and then the rain to wash it all off.but dont get it on plants or grass as it will kill them.and make sure you warn the customers that they are not to walk on it and then walk through there house as they will have white footprints where they have been, that will not come off
. after doing the jobs i usually leave and they think that they have paid u for nothing but, as i found out everytime i go back to a job to do there windows. They are allways so happy with what i have done, and ask me what it is. I say its some chemical i buy from the cleaning place i go, so remember to take the labels of the tubs before going to a job,or they will just go and purchase it them selves,then they wont need you next year,if you need any more imfo feel free to email me
dougies49@hotmail.com