Most of the signs can be seen from the ground and with the look of your roof. This leads to the roof appearing black or dirty normal in certain areas.
This could be a problem for your roof as it starts to weaken basic shingle cause them to loosen and decay. If you see dark areas on your roof and worried about climbing on your roof to get a better view then contact a reliable roofing contractor to inspect your roof and determine whether the stain is mold growth. You can take expert help about the wood truses and rafter roofs online.
Shingle and cause damage
Damage to the shingles, or even worse the roof sheathing, can be caused by a number of factors. Mold and mildew can damage the shingles organic base causing them to rot.
If this relationship is weak then it makes your roof more susceptible to loss during high winds during a storm potentially could eventually compromise the integrity of your roof. If your roof seems slack in that area could be a sign of a larger problem called rotten roof which can cause the collapse of the possibility of your roof.
By having a professional inspect your roof so that you can avoid the cost of additional repairs to the roof of your home's interior.