what are the signs you need to replace your roof?

Some think it is time when it starts leaking threw the ceiling but,
this can cause more problems because now you have water in your insulation, which can cause mold buildup which you do not want, because this means more problems and the thing is because you only see a little spot does not mean that is how big the problem is that's just all it shows,mold can cause colds,rashes and many more problems that go not noticed,
The time to fix your roof is if you go out side and see signs of roofing on the ground from the wind, shingles curled up on the roof your shingle should be flat on the roof if not this could cause back up of ice & water which can cause leaking if you see lots of algae buildup on the roof this means you need algae resistant shingles which also means you have trees close to your house and check to make sure there is no tree rubbing on your home because this will remove shingles in that spot over time.or an even easier way is think back to who owned the house before and what they said about the last time the roof got replaced if it was more than 15 years ago you need a new roof.