Page 277 - Masonry and Concrete

Masonry Veneer

276 CHAPTER SEVEN

wick is clipped flush with the wall. Mois-
ture in the cavity is absorbed by the cotton
material and “wicked” to the outside face
of the wall, where it evaporates. The rope
will eventually rot, but it leaves an open
hole for continued drainage. The rope
must be cotton rather than nylon to be
effective.
Through-wall masonry flashing must
be installed at lintels above door and
window openings, at window sills and
ledges, and at the base of the wall. Weep-
holes must be installed in the first
masonry course immediately above the
flashing. The wall sections in Figure 7-27
illustrate basic requirements of the CABO
One and Two Family Dwelling Code.
Brick masonry sills should be sloped to
drain water away from the window. The
masonry industry recommends a mini-
mum slope of 15 degrees. The flashing
FIGURE 7-28
system must form a complete barrier to
Expansion joint at change in wall height. the passage of water. Masonry veneer
should always rest on a ledge recessed
below the finish floor line so that the
flashing at the bottom of the drainage cavity collects and discharges
moisture at this less-vulnerable location.

7.6 Expansion and Control Joints

As discussed in Chapters 4 and 5, cracking in masonry is most often
related to the expansion and contraction caused by changes in
moisture content. The walls of residences are relatively short in
length compared to most commercial construction, so there is less
accumulated movement stress to accommodate. However, stress
buildup can occur even in small structures if not properly accom-
modated. Brick masonry expansion joints should be located near

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