Here are some of the common areas when repairs are needed and a basic rule of thumb when you need to evaluate repair vs replace:
Roof Failure: chipped paint, stains or discoloration on the ceiling are all signs of a roof failure. Obviously, you should repair it if it costs less to fix than replace and if the repaired roof will not survive a new full 20 year life cycle.
Roof Leaks: Water stains or discoloration, leaks under the shingles. You should repair the roof if due to flashing issues and the leaks are isolated in a defined small area. You should replace the roof if it remains wet under shingles; causing slow rot.
Moss/Mold/Mildew: Moisture leaks can cause growth of moss and dangerous mold and needs to be addresses quickly. You should repair the roof if only a handful of shingles are affected, and replace if the growth is rampant throughout the roof.
Aged Roof: Most roofs last around 15 to 20 years. If you don't know when your roof was last replaced, we can come do an inspection and help identify the approximate age. If the roof is younger than 15 years, and can be repaired, it should be repaired. If the roof is approaching 20 years of life, it's time to replace it.
Roof Shingles/Tiles: Over time, shingles or tiles go missing, fall off or get damaged. You should repair the roof if there are a few that are missing or damaged and replace if there are large amount missing or damaged, when it's cheaper to replace than repair.
Roof Shingle Layers: You should never have more than 2 layers on your roof - it gets heavy and could potentially damage the roof structure. You can add layers if the damage is small enough but you should replace if there are already two layers.