The roof you see below is a slate roof replacement Arlington, VA that had reached the end of its service life. When slates start to turn brown or show white efflorescent half moons in their faces it is a sure sign that they have begun to deteriorate; over the past 5 years the owner had spent a few thousand dollars patching up areas where slates had fallen out or where flashings had begun to leak. When slates deteriorate  they get soft and can drop out of their positions or just crack off entirely; its a long slow process when a slate roof starts giving up the ghost, keeping it on life support can get really expensive.  I know what you’re thinking “I thought slate roofs last forever?”; nope, some slates from only a few quarries will last for more than 125 years, some slate veins in those same quarries can produce softer slate that is more prone to water absorption. [Read more…]