- Q. What's the right way to
flash an exterior masonry chimney to the wall of the
house?
A.Fred Seifert responds: I
bend an F-shaped piece of flashing that catches the ends of the
bricks where they meet the house (see sketch). I use copper,
lead-coated copper, or aluminum and bend the flashing in long
pieces on an 8-foot brake. We nail the flashing to the
sheathing over the housewrap, then use a flashing tape to seal
the outside leg of the flashing to the wrap. The mason spaces
the brick away from the flashing so that any water that gets in
can drain down and out the bottom through metal weep channels
embedded in the mortar under the first course of brick.
Depending on the height of the house, it may take three or
more lengths of flashing to reach the roofline. At the joints,
I prefer to butt the pieces rather than overlap them, because
it looks better. To maintain a tight seam on the exposed kick
where the flashing meets the brick, I run a spline several
inches long inside the bend to span the joint.
Having passed down the family
business, Fred Seifert,
Sr., works for his sons, Fred and
John, at Seifert Brothers Construction in Mattituck,
N.Y.