Mastering Roof Inspections: Flashing, Part 6

by Kenton Shepard and Nick Gromicko, CMI®



The purpose of the series “Mastering Roof Inspections” is to teach home inspectors, as well as insurance and roofing professionals, how to recognize proper and improper conditions while inspecting steep-slope, residential roofs. This series covers roof framing, roofing materials, the attic, and the conditions that affect the roofing materials and components, including wind and hail. 



The IRC calls for flashing to be installed at areas where the roof changes pitch.

This would include areas where the roof changes from steep to shallow, and has either a concave…

…or a convex shape.

Another situation might be on a bonnet roof, as you see here.

Another common condition is where a porch roof meets a steeper home roof.

In looking at different roofs with changes in pitch, you won’t always be able to confirm the presence of flashing. The roof edge is the best place to look.

If you can’t confirm the presence of flashing in areas that you know should be flashed, it’s a good idea to mention that in a disclaimer in your inspection report. 


“Drip edge” is flashing installed around the edges of the roof to prevent roof leaks and wood decay.

You’ll see various flashing profiles used as drip edge. The type of profile you see isn’t as important as whether the flashing keeps the water out. Drip edge is not required by the IRC, and lack of it is not a defect; it’s just a good idea.

Unless a lack of drip edge appears to be an immediate or potential problem, you wouldn’t typically recommend that it be installed on an existing roof, but you might include in your report an explanation of the purpose of drip edge, and mention that none was installed on the home.

Generally, underlayment should overlap the drip edge at the lower eave, and drip edge should overlap the underlayment on rakes.

With a few types of synthetic underlayment, the manufacturers recommend that the overlap at the eave be reversed, with the drip edge overlapping the underlayment.  But with black felt, the underlayment should always overlap the edge metal at the eave.


Learn how to master a roof inspection from beginning to end by reading the entire InterNACHI series: Mastering Roof Inspections.

 Take InterNACHI’s free, online 
Roofing Inspection Course
Mastering Roof Inspections
Roofing Underlayment Types
Inspecting Underlayment on Roofs
Fall-Arrest Systems
Roofing (consumer-targeted)
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