Your Flashing Has Cracked:
Why it happens: In the event that your flashing is left exposed, elements like wind and rain could be the reason behind its crack
You Have Broken Shingles:
What does it look like Look up! Since shingles are the exterior layer of a roof, you should be able to identify missing shingles by seeing different-colored patches on your roof.
Your Valleys Aren’t Properly Sealed
How to fix it: This job should be done by a professional due to its complexity. Your roofer will fix the problem by putting in a new barrier and covering with shingles.
Your Gutters Are Clogged
Why it happens: Your gutters are meant to help water travel away from the roof. When a blockage forms and they get clogged, that travel stops. Rainwater will then pool in one area of the roof and have more of an opportunity to seep through cracks.
You’re Using It Too Much
How to fix it: Avoid walking on your roof whenever possible. Hire a professional roofer to do your fixes, since they are trained on how to avoid the most easily-damaged areas.