It could be time for the new roof if shingles slide off and/or grow to be cracked, brittle or curled or when darkish streaks look. Don’t believe these Unattractive stains are Dust. They could be moss, lichen or blue-green algae. Roof installation comes along with a two-calendar year labor guarantee. https://traffup.net/iframetest/?ID=1305856e9777c0fc2ebe1fc7cb209663