A
Anonymous
Guest
Hi, I have just replaced the lead flashing on my hip roof and the nearly new concrete tiles (sorry!) that I fitted last year have been badly stained white by water run-off from the old flashing -- which had clearly never been treated with patination oil. (Why did I not change this at the same time? Please don't ask..) I have researched this a little and the deposits are apparently lead carbonate. I need a solvent that will remove the stain but leave the tiles intact. I have tried vigorous application of a pressure washer to little effect. In my research I have found reference to a chemical called dimithyl formamide but as this is £30 a litre I am a bit reluctant to splash out just yet! Any ideas? Kind Regards.