The most common I see around my neighborhood is debris that is allowed to accumulate on roofs. It is a shame that this happens, because it is so easy to sweep off leaves from a roof. If allowed to accumulate, leaves will accumulate water and hold it very well. As the wet leaves accumulate and hold water, they will rot in place. Not only does the moisture build up and seep below your shingles, the rotting debris also begin to release acids and organic compounds that will cause your roofing material to loose its integrity – and then BAM! – high roofing repair bills!! Don’t let this happen to you; just spend a few minutes sweeping of your roof when needed.
Another item of neglect is the infamous leaves left in gutters. Not only is this bad for the foundation, water overflowing from leaf-filled gutters can find its way down the siding of the house, causing water damage. Even worse, water-filled gutters can find its way into roof edges, causing wood rot at the roof edges. I know it is kind of a gross job, but cleaning out gutters is a must to keep your roof and home in general free from unnecessary water damage.
One other suggestion is to keep trees near your home trimmed. Keep tree limbs from hanging over your roof. A good wind storm can lead to a branch hanging in your bedroom – not very romantic, eh? Also, keep branches from rubbing on your roof – branches rubbing on your roof will easily remove shingles.
I guess one reason people have for not maintaining roofs is fear of heights. I know this feeling too well. I do my own roof maintenance, but you can also hire somebody to do it for you. If you hire people to clean your roof, do remember to make sure they are insured!