Roof flashing - how to inspect for problems and how to flash it right

Ever wonder why you're getting a roof leak? Even when the shingles are in good condition? The answer is probably related to flashing. In this video, Garth Haslem The Home Medic shows you what flashing is, what to inspect for, and how to fix roof problems related to flashing issues.

[@A1TQC]

Actual guidelines for proper vent and pipe stack flashings is that two rows of shingles must be installed underneath the low slope
If professionally done, the installer will caulk contact points with flashing for every shingle.
Failed to address the exposed nails on bottom edge of vent flashing, gasket nails recommended, if using roofing nails they must not be overdriven like shown in video and must have sealant applied.
Also neglected to mention anything about the seal at top of pipe stack, cracked or caulked pipe seal indicates a need for replacement as your example showed.
Proper information can be obtained thru NRCA (National Roofing Contractors Association) or thru any of manufacturer installation guidelines