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Community and Q&A

Roof Overhang and Window / Door Head Flashing

slugboy6000 | Posted in General Questions on

When windows or doors are protected by a gable roof overhang, can I exclude the head flashings?
In this instance, rain would have to drive at an angle greater than 45° from vertical just to get the flashing wet and that would be an unusually bad storm for this area (SW Ontario).

Am I being lazy or sensible?


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  1. Expert Member
    Michael Maines | | #1

    Lazy ;-)

    I might consider eliminating head flashing if it is under a 10' porch roof, but even then it's not a lot of extra work to ensure that stormwater stays out of your walls.

    1. kyle_r | | #2

      Or when the siding is power washed…

    2. Expert Member

      Don't get in the habit of skipping steps! You'll be tempted later in even more precarious situations. Unless you're asking for a friend, and then I'd say he's being lazy.

  2. plumb_bob | | #3

    Our code has a 2:1 rule, so you are allowed to omit flashing on a window if the overhang is 2' horizontal, and the window is not more than 1' vertical below the overhang. So this is twice as conservative as 45 degrees.

  3. slugboy6000 | | #5

    Sounds good to me. A nice and simple code rule to remember.

    1. user-5946022 | | #6

      At some point during the life of this home, some person is going to powerwash it, and if you leave out the flashing, it will probably leak.

      Don't be lazy and cheap. Install the flashing.

      1. Expert Member
        MALCOLM TAYLOR | | #7

        user ...022,

        Head flashing is designed to channel water that gets behind the cladding out to the exterior - which means you have to leave a gap between it and either the window head, or head trim depending on where it is located. I'd not sure a window that was installed without head flashing, and fully sealed, wouldn't leak less when you power washed it than one which had the flashing.

        All that aside, I'd never suggest omitting head-flashing.

  4. DC_Contrarian_ | | #8

    Head flashing is like five minutes and $5 worth of materials if you're doing in on new construction. I'm not sure I understand the question.

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