For you homeowners, roofs are probably down there with politics on things to be thinking about, but in truth they are an important part of your home or structure. One thing many people do thats an expensive mistake is letting their shingles exceed their life without replacement. Shingles are tested by manufacturing labs and when they say a 15 year shingle, that means its effective life if 15 years. At the end of this period they may be wearing out. However, thats an average. If you live in a high sun area, high rain area, or high snow area, the life may be signficantly less. So its a good idea to have your roof inspected every 5 -6 years by a qualified roofer, inspector, or general contractor. Get one that has a good record and make sure they are licensed, that way they wont be trying to sell you something you dont need. And certainly look up when your roof war shingled last and if its getting to the lifespan of the shingles have them replaced.