Sweet Way to Bend Drip Cap For Windows
An upturned end dam for window flashing that needs no sealant and will not leak
Standard drip cap flashings slope 15 degrees past 90 degrees, so, 105 degrees with a drip edge. Some builders leave the ends open, which can allow water to sneak under the flashing to the window. others cut a small slit in the 105 bend which allows them to fold the flashing down.
Mike Gandy has another way. He folds the end piece up to direct water out rather than allowing it to dribble into the side cracks between the window trim and the siding. He does it without the need for solder or sealant. It is just simple coil stock origami.
Step by step head-flashing end-dam bending process:
- Mark one inch in from the end and another about 1/2 inch in from the end.
- Add a couple of marks on the upright back section, which sits against the wall, at one inch and one-quarter inch, connect the dots with a pencil line.
- Cut down the 1-inch line to the diagonal mark and cut in from the end to the quarter inch mark. Connect the cuts along the diagonal line on the upright leg of the flashing.
- From the bottom, cut up the drip edge at the one-inch line, and then cut in from the side along the drip edge fold to the cut you just made.
- Now, cut from the bottom corner on the flashing diagonally up toward the 1/2 inch line.
- Use seaming pliers to fold the cut end up. place the left corner of the pliers at the fold holding the pliers at about a 45-degree angle to the flashing.
- Fold up. This causes a triangular protrusion at the end of the flashing. Squeeze this loose triangle together with the seaming pliers and fold forward. Use a block of wood and a hammer to tidy-up the bend.
- This forms a sealed inside corner. To finish the end, fold the top half of the end flap down, and then fold the front corner over the fold you just made
—Mike Gandy is a carpenter in British Columbia