Through-wall flashing, end dams and weeps: methods and worked application

Ten steps in a column: check the drawings and the metal, clean the bearing, bed the flashing from the face to the backup, run it past the opening, form and seal the end dams, lap the pieces by the method the specification names, terminate behind the barrier, place a mortar collection device, lay the first course with weeps above the flashing, and inspect and photograph before covering.

1

Check the drawings: material, rise, extension past the opening, dam positions, joint method and weep spacing

2

Clean the bearing; the water/air barrier is already on the backup before the flashing (IMI)

3

Bed the flashing in sealant from outside the face across the cavity

4

Run the flashing past the opening and up the backup at least 8 in

5

Form and seal the end dams, at least 1 in up, at or beyond the lintel ends

6

Lap the pieces: a 6 in sealed lap (BIA's figure for plain flexible flashing, York's for its own stainless; sheet-metal splices follow the maker) or, for concrete masonry, a 1/4 in gap under a bonded membrane (CMHA)

7

Terminate the top edge, then lap the water-resistive barrier over the flashing afterward (BIA, at least 6 in)

8

Place a mortar collection device above the flashing

9

Lay the first course with open head joint weeps immediately above the flashing

10

Inspect and photograph before any brick covers the flashing