This video by Aron Jones, in honor of International Flashing Awareness Day (#internationalflashingawarenessday), illustrates how to bend an end-dam on a piece of head flashing for windows and doors. There are many ways to bend a head, and not all of them work as well as others, but something is generally better than nothing.
Bending the ends down is one upgrade to not detailing the ends at all; this method bends the ends up, creating a sealed pocket (without using sealant) that directs water down and away from the window and siding. This method is better than simply bending the ends down.
Video transcript:
Several people have asked how I make my head flashing end dams, and there are a few things you need. A good pair of snips—lefts and rights—go a long way. Some folding pliers or hand seamers are necessary, depending on how big this leg is and how big of folding pliers you need. You’ll also need a square and a pencil.
Occasionally, a hammer with a tapping block comes in really handy for just tuning things up.
Laying out the head flashing measurements
There are many ways to lay this out, but this method works well for me. I make a mark at three and a half inches, and today I’m going to draw more lines than I need to make it clear for everyone. I make a mark at two and a half inches, and I make a mark at one and a half inches.
Again, you can use any square. I like this one because I can see through it, but any square will work.
Transferring and labeling the layout marks
That’s my mark at three and a half inches, that’s my mark at two and a half inches, and I transfer that mark all the way up. This is my mark at one and a half inches.
Now, coming down onto the drip, I’m going to make a few more marks, and then we’re going to label everything we’re going to cut out and everything we’re going to keep. I’m working on a template that’s going to be usable for any type of brick mold, flashing, or head flashing.
Some people like to lay out a 45-degree angle here. I prefer to have a mark that matches the angle of my drip.
Identify what to keep and cut
So, here’s what we’re going to do:
- We’re going to get rid of all of this.
- We’re going to get rid of all of that.
- We’re going to keep this piece here.
- We’re going to keep this, this, and this.
- We’re going to get rid of all of that.
Cutting and folding the metal
I’m going to take my time cutting the head flashing here today. Hopefully, I’ll be able to explain everything I’m doing as I go. I try to keep the same pair of snips in my hand as long as possible, but you do need red and green snips to do this properly. Again, we’re removing what we don’t need.
Now, I’m going to come at this twice on that leg, and you’ll see why in a second. I could have done this all in one go, but for explanation purposes, when we get to folding, you need to remove a bit more from this area. It will become apparent when we do the folds.
I don’t need quite all of that, so I’m going to shorten it up a little bit. I’ll bend that up out of the way and come across here. Now, I have to make a fold here before I finish the last cut. Fold that underneath, which will help prevent water from traveling that way. I overcut that slightly, but it’s okay.
The first bend creates a watertight corner
I’ll take my time folding as much as possible. This is the first bend, or the first fold. Depending on the size of the leg, you’ll need hand seamers or folding pliers. This is the "magic bend" that creates the watertight corner. You’re going to want to crimp that nicely and fold it back a little bit. You’ll see in a second why.
The second head flashing bend is the top of the end dam. Bring that over, and again, you want it to be nice, tight, and crisp, because people are going to see that. You’ll have to make a cut at this point. The more material you leave on here, the easier it is to fold, and the more you’ll have to grab onto.
There are a few other methods I’ll show at the end in case you don’t have a really good set of hand seamers or folding pliers. This is a quick and rough method.
Final head flashing bend and cleanup
The last bend is folded underneath. That’s a completed end dam. Once you have it all completed, if you’re not completely happy with it, you can still manipulate, twist, and tweak things.
Sometimes, especially with steel, you’ll have to take a mallet or a hammer with a hardwood or Teflon block and just clean things up a little bit. You want to tidy up so you don’t have sharp edges or bends that aren’t clean or crisp.