Install a piece of step flashing over each shingle in a weave fashion.
How to install step flashing on existing roof.
With step flashing you do a little flashing then a lot of roofing then a little more flashing and so on.
When retrofitting step flashing you will need to slide the step flashing up and under the existing shingles.
In order to properly install new flashing you ll have to remove the shingles surrounding your old flashing and then re lay them after installation.
Wide and 2 in.
Once the shingles have been installed lay the base flashing around the base of the chimney approximately 4 past each end.
Each piece of step flashing laps over the shingle below and under the shingle above.
Length to extend 5 in.
Step flashing for chimneys.
The roof deck flange of step flashings are to be fastened to the surface of each shingle in a position whereby the next course of shingles will cover up hide the flashing from view.
Longer than the shingle s exposure.
Make sure the caulk joint between these two pieces is bedded evenly.
Once even a small section of roofing cement fails you ll have a leak.
Secure the screws but do not overtighten.
It may seem as if a single piece of flashing would offer more protection than many pieces of step flashing.
Install the roofing screws vertically along each rib in the panel.
Proper installation of step flashing.
The bottom edge of the flashing should extend just below the nail line.
Installing your roof flashing is going to be slightly different depending on the specific type that you re installing.
Flashing is generally installed at any joints or edges in the roof where water could otherwise work its way in.
This allows each step flashing piece to overlap the piece below.
Continuous flashing against a sidewall is one way to install a roof but it s not the correct way.
Place the first screw about 7 inches from the bottom and each subsequent screw about 18 to 24 inches apart along the vertical run.
Now notch the first step flashing so that it will bend to go around the chimney front and side as well as at the base.
Typically flashing is installed using roofing nails and roofing cement.
Step flashings are to be installed one per course.
The washer under the screw head should seal to the surface of the panel without bulging or shifting.
Cut step flashing pieces to be 10 in.
The first piece of step flashing needs one bend so that it laps cleanly over the corner flashing installed in the previous step.
