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Head Flashing for Windows

September 28, 2016
Read time: 1 min


This critical element is often omitted from window installation


Shaped like an L, the upturned leg should tuck behind the house wrap. The horizontal leg protects the window, by directing water out and away. 

This flashing is important because a caulk joint between the top of the window and the siding will crack over time. 

To order or bend head flashing:

  • Measure the depth that the window projects from the flange, 1 inch in the case of the window in the video.
  • Add 1/4 inch to allow the flashing to project a kick out and add another 1/4 inch for a hem.

When installing, cut the flashing 1/4 inch long on each end and turn up the ends to create an end dam at either end which will direct water out. Squirt a little sealant into the cut corners of the end dams, just to make sure the water knows who is boss.


—Matt Risinger is a custom builder, remodeler, and YouTuber in Austin, Texas


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