I am familiar with them, but around here they are not used very much. Mostly just on older roofs with metal vent stacks.
When you zoom in on the pic the area above the shingle the arrow is pointed at is sunken, appears to be bad sheeting. Moisture/ventilation problem
Don’t see any roof ventilation, ridge or other.
Good afternoon, sir. I’m from the Northeast and we used to use an aluminum flashing with the rubber grommet that went over top of the PVC to seal it. However, the PVC breaks down in the sun that is intense in Florida and so we need to cover everything. The
biggest damage we have with that flashing is the fact that squirrels like to chew on them and create holes along the top edge where it’s folded over the PVC. I have never seen this type of flashing until I came down here about six years ago.
Reform, I enjoy reading other peoples thoughts and opinions.
Chuck
The roofer had already repaired the shingles by the time I had a chance to check them but I went into the attic and this is what I found.
The areas just above and below the light are where the leak was coming from. Looks like you called it.
The photo isn’t clear enough to count the courses from the roof eave accurately (I guess 29 courses figuring about 5.5" per course). My rough count divided by 48" indicates that the problem doesn’t land on a sheathing joint.So I’m guessing Chuck is right and it’s a wrinkle in the underlayment. If it appeared to land on a joint, then Marcel’s guess would be more likely.
I’m not making any declaration as to the specific cause in this case, because it cannot be verified from the picture. I simply stated that the most common cause (at least in my experience) is an underlayment irregularity. I have also seen plenty which were due to sheathing issues, as Marcel points out.
When walking the roof, it’s easy to tell which, by feel. Underlayment will give with very little pressure while roof sheathing has a rigid feel to it. The root cause could easily be either and is readily verifiable from the rooftop, but not from this rooftop photo or the attic photo.
From the picture of the attic the OP posted, sure looks like a section of sheathing was replaced and also note the lack of H-clips again and the differential with the other sheathing.