Installing Lead Step- and Counterflashing

How to install a roof-to-wall counter flashing and custom-cut one-piece step flashing into a brick wall.
May 20, 2016
2 min read

Lead flashing, British style

Gary, from Aspect Maintenance demonstrates how to install a roof to wall counterflashing cut into a brick wall, using rolled lead flashing.

Step by step counterflashing:

  • Cut a chase in the brickwork 6 inches above the flat of the roof wall intersection. Grind the channel about an inch to an inch and a half deep into the brick mortar joint.
  • Use sections of lead about a meter or a meter and a half long top work with.
  • Bend along the length, about an inch, to make a leg to tuck into the channel.
  • Cut 1 inch by 6 inch strips, and roll them into bungs.
  • Flatten one rounded edge of the bung with a hammer so that it will slide into the chase more easily.
  • Use a hammer to pound the bung into the channel and then use a chisel to pound it in tightly.
  • Space the bungs every 12 inches or so.
  • Overlap the next piece of lead about 6 inches over the previous piece.
  • Use a lead dresser to dress the lead to the wall.
  • When the lead is installed, bunged, and dressed, point the joint with mortar to deflect water away and out.

How to cut step flashing into a long piece of lead flashing

 

Step-by-step step flashing

  • Mark the cuts in the brick courses with a straight edge and a pencil.
  • Cut perpendicular to the edge of the lead flashing, from the end of one mark down to the beginning of the next one.
  • Cut parallel to the marks, an inch above each mark, to remove a right triangle of lead flashing.
  • Slide the flashing into place and dress the lead against the wall.
  • Bend each saw-toothed in the lead flashing 90 degrees, at the scribe lines. These bends will insert into the brick cuts.

Slide the flashing into the cut channels, bung, dress, and point.

 

 

About the Author

Dan Morrison

Dan Morrison is a founding editor of ProTradeCraft.com, where he is also the editor-in-chief. Fun fact: Dan is also a founding editor of Green Building Advisor and executive editor of Fine Homebuilding.

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