Scott Bachman

Les, That's the type of explanation I was looking for. Nothing else seems to fit. Scott

The first photo is near the ridge and near the east gable vent. That one I can attribute to moisture leak. The second photo is at the eave near center of attic. It is the cold north slope. Have seen mostly NW winter winds prevailing. The ridge almost certainly was opened up at the last shingle replacement (approx. 5 years) or the one prior. This is for my information only. Other issues with the roof warrant roof repair/replacement. Last install was a poor attempt by homeowner. My curiosity keeps going back to the pattern on the eave photo. It was very defined, every other T&G deckboard. Thanks for all replies, Scott

Mike, Answer to you other question. Both locations on north facing slope. Scott

Yes, southern yellow pine. The shingles were adhered well enough. A local contractor suggested missing tar paper at this location, although that doesn't explain the unusual pattern. Both locations are basically isolated to what is visible in photos. Scott

New contributor. Hello to all. I did a roof inspection on Friday for a lender. 1958 house, tongue and groove deckboard, with soffit, gable and ridge vents. There were two isolated areas of frost on deckboard in attic. One area of frost covered deckboard (3'x3') shows obvious leak stains (see photo). The area I am unsure is the other photo. This is a different location in attic, near the eave, above bedrooms. As the photo shows, the frost is on every other T/G deckboard. No signs of leakage/stains. The pattern is what throws me. This is my 1st frost in attic (moved from central Florida last summer). The shingle covering is poor quality, homeowner installed, several years ago. Any info what be helpful. Image Insert: 114.64 KB Image Insert: 119.2 KB