J-channel
A J-shaped trim that receives the cut edges of siding around windows, doors, and roof lines and hides them.
What it means for you
A tidiness-and-water detail. Where siding meets a window, the J-channel should be flashed and lapped so water sheds out — not caulked into a dam, a common shortcut that traps water behind the siding.
Where you'll see it
Around every window and door on a vinyl siding job.
Related terms
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