Lead stains.

I have a mate who is a window cleaner and he was asked on one of his jobs if he had any way of cleaning the staining on a couple of walls that apparently has been caused by the lead flashing.

I havent seen the walls myself so I cant obviously say if the staining is actually being caused by the lead. The walls are finished in a dry white dash. Does anyone know of any cleaning product thats available for this type of problem or has anyone encountered this themselves?

The stains are most probably caused by carbonates released as the lead oxidises. I would try "brick acid" (on a small area of) the render to see if it shifts it OK. Make sure to treat the lead with patination oil to prevent this staining recurring.

i think you are meant to seal lead to keep it from running i.e. those white marks you sometimes see on roofs. would seem better to get the problem of the lead running fixed first.

Having been involved with Lead Manufacturing, this type of stain normally washes out quite easily. Has he tried a heated pressure wash ? If no joy, try contactingMetal Processors in Clondalkin in Dublin. They should be able to assist you.

Thanks for the feedback folks. Much appreciated.