Flashings are needed at all roof penetrations, such as pipes, chimneys, and ventilation components. These areas are responsible for the majority of roof leaks. Careful and proper flashing installation will minimize the possibility of leaks.
Read these excellent articles:
Flashing, Part 1 – InterNACHI – What are flashings?
Flashing, Part 2 – InterNACHI – Roof-Wall Intersections
Flashing, Part 3 – InterNACHI – Counter-Flashing
Flashing, Part 4 – InterNACHI – Kickout Flashing
Flashing, Part 5 – InterNACHI – Changes in Roof Slope or Direction
Flashing, Part 6 – InterNACHI – Changes in Pitch
Roof Penetrations, Part 1 – InterNACHI – Chimney
Roof Penetrations, Part 2 – InterNACHI – Chimney (cont’d)
Roof Penetrations, Part 3 – InterNACHI – Vents
Roof Penetrations, Part 4 – InterNACHI – Vents (cont’d)
Roof Penetrations, Part 5 – InterNACHI – Skylights & Mechanical Attachment Points
Pipe Flashings (Pipe Jacks)
The most common item is the pipe flashing. A single roof may have many pipes penetrating the roof, and each of these pipes need a proper seal to keep water out. There are three types of pipe flashings that SEI Roofing uses: 3-in-1, lead, and the Bullet Boot.
A 3-in-1 jack is the most economical and is “trim-to-fit.” It is made of rubber and will fit a variety of sizes after trimming. They’re easy to install and the most widely-used. However, weather and UV radiation may cause deterioration over time causing failure.
A lead pipe jack is also very common, but more expensive. They come in specific sizes, so you must know the pipe size on the roof to replace it. This style will last a very long time except when squirrels chew on them and damage them prematurely.
The Bullet Boot is a soft, size-specific flashing that is easy-to-install, and has a long lifespan. However, they are more costly than the 3-in-1 or lead pipe flashings. Watch this video:
Here is a video that looks at flashing around a vertical wall using step-flashing.
Here is a video looking at drip edge.