The height of the section of step flashing that is applied against a vertical side surface (wall or chimney) must be at least 2β high, but for additional protection, use step flashing with a greater height.
Itβs okay to fasten the step flashing to cap flashing
The base flashing used against a vertical front wall must:
Be a continuous piece of metal up to 10β in length.
Be embedded in asphalt plastic cement.
Extend up the wall at least 2β.
All of the above.
A cricket:
Projects through the roof and should be handled like a round vent pipe.
Helps to prevent a build-up of ice and snow at the uppermost side of the chimney.
Is put in position after the underlayment has be applied.
Is fastened to the deck with asphalt plastic cement.
Cap Flashing, continuous counter flashing and surface mounted counter flashing are three flashing methods used on chimneys.
Base flashing is required at the point where a dormer meets a sloping roof.
When installing a closed-cut valley, first lay the shingles from the roof with lesser area across the valley and on to the adjoining roof area at least 24 inches.
Generally, the valley method preferred by Certainteed is the closed-cut method.
Open valleys are recommended for Grand Manor, Carriage House, Landmark TL, Presidential Shake, and Presidential TL.
The alternate closed valley application is recommended for 3 tab shingles.
Flashing a skylight curb requires apron flashing on the base, step flashing on the sides, base flashing on the upslope side, and a kick-out diverter.
Hemmed edges on flashing that are turned upward create air gaps that resist the movement of moisture from the metal to the roofing.