If you have asphalt roofing shingles on your home, you might also experience stains and moss growth on them. It is possible that this is a sign of a serious problem that could seriously damage your roof.
There are many possible causes for this.
If your roof is over 15 years old, it is possible that the surface material is wearing off the shingles. When this happens you can see the asphalt base. If this is the case, your best solution is to replace the roof.
Another possible cause is algae growth. This can start as blue, green or black stains that might eventually cause streaks. This doesn’t harm the roof, but it does detract from the look of your home.
Moss on the other hand can damage your roof. Remove it as soon as you notice it.
To clean moss or algae off your roof, you can use a 50/50 solution of bleach and water.
Preventing moss or algae from returning can be done by clearing away branches that block sunlight from your roof. You also want to keep the roof clear from leaves and fallen branches since these will collect moisture.