Alright I have to be real quick here because it ticks me off when this happens to people - especially investors. Make sure your roofs are vented enough! I just had another insurance claim where a $20,000 roof failed in 12 years. (about 1/3 of it's life). The simple reason why is there was inadequate ventilation. Inadequate ventilation stores air and moisture and heats it up in your roof in the summer and turns it into a wood warping, mold sporing, shingle cracking orgy of expenses.
I don't need to say much more except vent them roofs! If you're not sure if it's venting properly, go in the attic in about 80 degrees. If you're sweating more than Ruben Studdard in 3 seconds - get a roofer to check about putting in a few turtle vents. It's a much cheaper option than paying for a whole new roof.
And no - the $20,000 claim is not covered because it was faulty construction. That means it's 100% out of pocket for the owner. Any of you have an "out of the blue" $20,000 loss figured into your pro-formas? Vent!