Black stains are ONLY on shingle roofs

Many clients are concerned about the black staining that happens from blue-green algae on roofs. This seems to be connected and directed toward shingle roofs. The reality is that if your home is located with any trees around it, it will happen no matter what roofing material you choose. I recently did a roof inspection on a 6 year old metal roof, I will include pictures of it to show what can happen even on a smooth, painted roofing material. This roof was a medium Charcoal grey and already does not have a very good appearance.

I am also including a picture of a few random roofs I passed recently. I do not know the age of these roofs, but I wanted to show what happens if they are not cleaned. As a side note, most paint companies require regular cleaning of metal roofs to support the warranty.