My Library

course and is bent up along the wall under the sheathing membrane. The squares must be large enough to give a good lap at the intersection of the roof and wall, and the head lap should be no less than 75 mm (3 in.). A through-wall flashing should be installed over the base flashing, through the full depth of the masonry veneer and air space behind, and extended at least 150 mm (6 in.) up the wall sheathing (Figure 125). The sheathing membrane should lap at least 75 mm (3 in.) over the top of the through-wall flashing.
Flashing should also be installed at the intersection of shingle roofs and walls clad with materials other than masonry. It should extend up the wall not less than 75 mm (3 in.) behind the sheathing paper. A saddle or “cricket” should be installed when the upper side of a chimney is more than 750 mm (30 in,) wide. These are constructed out of wood during the roof framing operations and are usually covered
125 Flashing at wall intersection
install building paper (diagonally) to cover joints in the counter flashing
minimum overlap 75 mm (3 in.)
counter flashing; mechanically fasten flashing to sheathing with flat-head galvanized roofing nails at 300 mm (12 in.) o/c, min. two per segment 100 mm (4 in.) min.
end dam stepped base flashing (only two sections shown for clarity) shingles lap over flashing. Flashing interwoven with shingle courses minimum overlap 100 mm (4 in.) minimum overlap 75 mm (3 in.)
solder or install sealant at all joints
Typical counter flashing segment