Garage Felt shingles leaking / mould on inside

[Badger40]

Hello,

First year in this house and noticed some yellow mould on the inside of the garage roof either side of the truss running all the way down. I’m assuming the felt shingles on the other side of the ply are letting water through. I got on the roof for a look and they look ok although there is some moss growth in places. Nothing seems loose.

What can I look for / what can be repaired? Never had felt shingles before so this is all new to me.

Thanks for any input.

 

[Wayners]

Kill Moss.

Ventilation either end of garage so you don't get condensation.
You might need some insulation to stop the mould...
Need more information to get you a better answer

 

[Badger40]

I’ve sprayed with wet and forget the worst of the moss isn’t quite where the worst of the mould is but not a million miles away.

 

[Badger40]

Does anyone think blackjack or similar over the top of the leaking area all the way the roof in a strip would help?

 

[ree]

OP,
The colored Fungi and dead Tendrils could suggest perhaps a more serious defect than condensation?
Why not clean off all traces of fungi & tendrils - then probe the truss timber for softness, and then force spray fungicide between the trusses & the roof sheathing.
Remove all moss from the asphalt shingles by painstakingly lifting/flapping up each individual shingle.
the bottom three courses of asphalt shingles are repair courses or roof extension courses - is there a flat roof below the shingled roof eaves?

 

[Badger40]

Thanks for the replies. I assumed as the damage is located in line with the truss and not widespread it was water coming in from outside. And that’s where I should focus on looking for a leak / damage or apply some sort of repair. I will look for condensation.

Is wet and forget suitable for hitting this stuff with?

I will get a picture but the felted part is a lean to type shed built on the back of the garage.