Question: how do you know when you need to replace roof?
Answer: Asphalt roofing shingles with curled edges. ...  Cracked asphalt roofing shingles. Visible signs of aging on a 3-tab asphalt shingle roof. 3-tab asphalt roofing shingles with algae/dark stains. Moss growing on asphalt roofing shingles.