Ok, please hold back the jokes and take it easy on me as I describe my issue...this is my first post :-) I've heard good things about this group, so here it goes:
I have been getting some discoloration in my living room ceiling starting just below where dormer meets the main roof (a flat, not A framed dormer). I inspected the area of the main roof right under the shingled dormer and found the OSB rotted out. (good fire starter and sawdust)
The valley is completely shingled where the dormer meets the main roof and there is little slope where the water should be running off from the valley to the main roof.
What I'm not sure is whether the water is coming through the bottom corner under the flashing, or pooling somewhere and coming in under the main roof between the corner of the valley and wall of the dormer (or maybe it doesn't matter?).
Any suggestions on how to figure this out, so I can identify my problem area before patching the damaged area below? [Being a newbie to roof repair, I'm trying to avoid tearing up more than I need to]
Thank you in advance for any advice!