How to Install Step Flashing with a Shingled Roof

Man installing flashing around a chimney
  • 2-10 hours
  • Intermediate
  • 0-200
What You'll Need
Roofing nails
Nail apron

Installing step flashing on shingle roofs can be a rewarding task for one to accomplish by him or herself. By doing this, you will ensure you will have no water getting into your house where the walls and the roof may meet as well as other parts of the roof such as the peak. There are not many tools you will need for the job and there are a few ways to start off.

Before installing your step flashing, you should first install the drip edge. The drip edge must be installed before you roof or apply the step flashing.

Step 1 - Corner Flashing

Step flashing is not a hard process for you to complete. In fact, it can save you money if you are having your roof reshingled. If you choose to rip off the existing shingles, you may want to tackle this as well. The first part of installing the step flashing is the installation of the corner flashing. You will start by snipping one of your pieces of step flashing at a forty five degree angle. You will want to place the lower portion of the step flashing against the roof and the other edge goes around the corner edge. Nail the piece of flashing in place and lay some caulk around the edges.

Step 2 - Step Flashing

ladder leaning against gutter of a house

With the corner flashing installed, run the first row of shingles. After your shingles are laid down, begin to lay your step flashing. Place the next step of flashing approximately 1/4 inch above the next row of shingles, which will prevent the flashing from being seen. After you have laid down your first row of step flashing, you will continue this same process until you reach the top of the roof. You will not need the caulk until you begin installing the step flashing at the top of the roof, known as the roof peak.

Step 3 - Roof Flashing

After you have completed the flashing up to the peak of the roof, install the flashing on the roof peak itself. You must first design a piece of flashing that will fit on your peak. Once you have customized a piece of flashing for your peak, nail it in place and put some caulk along the edge of the flashing as well as run it along the wall.

Then continue this same process as you go along the peak of the roof. Make sure your caulk beads are straight and even so you don’t have excessive drippage. After you have completed running your roof flashing, you are now ready to allow the roofing company to come in and run the rest of the shingles although considering what you have done so far, shingles are very simple.