[Slatercleaners]

I've a few customers in quite new houses and their windows at first look dirty. Then I clean them, but there are stains that are quite clear but will not scrape or rub off. I reckon it must be something to do with lime washing out of the mortar, but am just guessing.

Any ideas? Any possible solutions?
Thanks
Gary

[replacement]

MDR and 000 Gauge Steel wool you need. Most window cleaning suppliers have MDR but the steel wool your have to goto a hardware shop.

Justin

[WavieDavie]

Next time you're there, take a look at the lintel above the window. I'm willing to bet that instead of being level, it tilts down slightly towards the window and allows any rain on the building to run onto the glass instead of just dripping off when it gets to the lintel.

If that's the case you have two options - say nothing and get the repeat job every year or so when it becomes noticable again, but they'll eventually twig, or tell them to get back to the builder to put a bit more mortar on the underneath of the lintel so that it's level or even slopes down away from the window.

What's happening is that when the rain runs down the building it's picking up mineral deposits from the rendering, cement, etc, and leaving it on the glass. Something on the same lines as stalactites/stalagmites, and I've been told it's called Concrete Cancer.

PS MDRs the stuff but read the instructions - use eye protection!!