If an unsightly roof (fungus or mildew stains or moss growth) is what is making you think you need a new roof, you need to learn more about what is under the stains or moss. There is not always a correlation to a dirty roof and it's life being over. There are most certainly roofs that will not withstand even the gentlest possible roof cleaning without sustaining damage that puts it in poor condition. Particularly with moss, as experienced in the Portland Oregon area, there are some moss types and infestations that cannot be properly dislodged without stressing a roof. If a roof is on the borderline to start with, such a roof is best left alone and the funds save for going toward a new roof. |
That exception being made, most roofs that are simply dirty would benefit for the gentlest cleaning available to solve its particular issue. Cleaning the roof will most often help maintain roof life, specifically where growths such as moss could cause "micro-dams" on the roof and result in damage. Always be sure that the roof has adequate life remaining so that your maintenance dollars will not be wasted.
For composition roofs (the most common type), granules, or lack there of, are the primary indicator of remaining roof life, much like the tread on a tire. If a roof consistently has lost a lot of its granules it is definitely time to replace it. Without an adequate amount of granule, which helps reflect the UV rays and protect the more sensitive lower layers of the material, the roof will soon be leaking. However, if the roof has enough granules that you consistently cannot see the underlying composition layers, the chances are good that, withstanding other issues, it might have more life remaining.
Even with adequate granule, if the roof's shingles are starting to cup or curl upward, it may also be time to consider replacing. Cupping and curling often are signs of interior ventilation issues that result in excessive attic temperatures. It is a problem you would want corrected with the new roof installation because it takes life off a roof that otherwise might have had more life remaining.
Loose or dislodged shingles may signal an unfortunate, premature death of your roof. Quite often this is a sign that the roofing material was victim of an installation faulty, even if the material itself has more life remaining. Similar to leaks, the number of trouble spots will tell you a lot. If it is only one trouble spot, you will likely only need to go with a roof repair. Multiple locations, however, indicate the bad installation mentioned above and you will need to get it replaced.
Related Articles -
Roof, Roofs, Roofing,