I saw this today and am not sure if its a past thing or if it is a currant issue. The
majority of the nails were rusty and moisture staining around them. The roof looked fairly new with little to no moss build up. There was an area with pine needles but this was consistent with the entire attic. Ventilation seemed great and moisture in the sheeting ranged from 11-17 averaging around 14. Could this be as simple as nails left behind from last covering or is this an an ongoing problem. I also double checked for the felt paper under the roof covering and it was there and appeared to be more than adequate. Any suggestions on how to report.
My first thought would be how functional is the venting system to the attic…poor venting can result in condensation collecting along the nails (fastners) resulting in the rust and moisture wicking into the substrate.
Report what you observed… noted roof fasterners throughout the underside of the roofing substrate were rusting with moisture stains around same (note if stain is active), recommend professional roofing contractor or licensed general contractor familiar with proper venting practices further evaluate same.
I would guess the sheathing had mold growth present and during the reroof ventilation was added and mold remediation performed. You can see the overspray on the trusses.
