I've got lots of drip marks on my face boards. The source of the drips has now been fixed by throwing immense amounts of money at retiling the roof. How can I easily cleanup the drip marks? I thought they'd just polish off with a rag, but they seem to be more resilient, like scale marks on a sink.
Kilrock seems a bit extreme, not to mention expensive - I don't want to damage the paint, since I'm trying to avoid repainting the whole lot. That was done recently anyway.
The other question is - how have I ended up with scale marks when this is rain water we're talking about? My roof is not made of lime or chalk!!