Right way to do head flashing end dams
Cottagebuilder
| Posted in General Questions on
Hey all, we’re going to be making window and door head flashing soon. I’ve been looking at videos and guides on how to do end dams. Hammer and Hand has a very straightforward way of making the end dam: https://hammerandhand.com/best-practices/1-2-head-flashing/
But some folks do end dams pretty elaborately like in this video:
https://m.youtube.com/watch?v=4kT0aIpx2wA&t=135s&pp=2AGHAZACAQ%3D%3D
So my question is, is there a right or wrong way to bend end dams? What is the advantage of doing more cutting and bending as oppose to what Hammer and Hand shows?
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Replies
Cottagebuilder,
That’s a very nice looking end-dam. Functionally I’m not sure it’s any better than the Hammer and Hand one.
End-dams are there to stop water moving horizontally and getting into your rain-screen cavity. They need an appropriately high vertical leg, which can be bend so it is continuous, or simply cut and sealed at the back edge with caulking. The rest is really aesthetics. Got a sunny afternoon with-nothing else to do? Fly at it. Otherwise I’d stick with a simpler version.
If you want a nice finished edge for a tall end dam and you're using aluminum so it needs some extra stiffness, or you're doubling your sheet metal over to hide an unfinished side, use the complicated method. There is probably a reason to use that method instead of a simpler method.
If you have shorter end dams, and your metal will be painted or is pre-coated the same color on both sides, the Hammer and Hand method is fine.
Additional complexity is fine, but it should add value or provide a solution to a problem.
Great, thank you both. My next question is, should the flashing be the width of the buck or just the width of the window? I have exterior insulation so I have window bucks. The 2x4 window bucks are roughly 3in wider than the window. Making the head flashing the width of the buck at the top and then bending to the width of the window would be interesting. My concern is water being able to get on top of the window buck in a worst case scenario and not having the full width of flashing there to shed out the water.
Does anyone have any pictures of head flashing for a window installed on a buck?
Edit: Should I just do it like in this video? https://youtu.be/W5zR3GeUjG4?si=b0s03fIl9GLdyhy7
The only thing different I would want to do is bend the end dam so it doesn’t require caulking.