OP
Mainiac Mat
Well-known member
Your question left me scratching my head as I hadn't noticed this detail... So I got up close on a ladder to see what they actually did.
Architectural shingles don't have slots in them, and the top half is but ugly. So these guys trimmed the top of the top shingle tight to the wall, and then laid the flashing over top of it. Then they trimmed shingles in half and laid a row of just the (aesthetically pleasing) bottom half over the top of the flashing, but under the clapboard lip.
most water coming down the roof will drip off the clapboard onto that top shingle. Any that blows up under that ledge to the wall will run down the flashing, under that top "trim" clapboard and onto the top of the highest regular coarse.
Kind of a nice way to detail the intersection. I've shingled more than one house in my time, but have never terminated a roof into a wall, so I've never seen this detail up close before.