Page 269 - Masonry and Concrete

Masonry Veneer

268 CHAPTER SEVEN

provided by applying a layer of 15-lb.
DOUBLE ROWLOCK SOLDIER asphalt-saturated felt or polyolefin house
BRICK ARCH BRICK ARCH
wrap over the sheathing. The felt or house
wrap should be lapped shingle style in
horizontal layers to shed moisture (Figure
7-21). If the space between the masonry
and the backing is grouted, paper-backed
welded wire mesh may be attached
directly to the studs in lieu of sheathing.
Where masonry veneers are installed
over a concrete or concrete masonry back-
FIGURE 7-19
ing wall, the cavity face of the backing
Soldier and rowlock arches. wall should be coated with a mastic damp-
proofing to provide increased moisture
resistance. Mastics can be applied by
brush, roller, or spray and should be care-
fully worked around anchors, plumbing,
and electrical penetrations to provide an
adequate seal (Figure 7-22).
The drainage cavity type of veneer con-
struction provides the best long-term ser-
TEMPORARY
PLYWOOD
WOOD DOWEL CENTERING viceability, but the cavity must be fitted with
SPACERS flashing and weep holes as described below,
and kept clear of mortar droppings for
FIGURE 7-20
drainage to be effective. The masonry indus-
or later tuck pointing. try recommends a minimum drainage cavity
width of 2 in. because it is felt that a nar-
rower cavity is difficult for a mason to keep clean during construction. A
narrow cavity is also more easily bridged by mortar protrusions, which
greatly increases the likelihood of moisture leakage through any defect
which might exist in the backing wall. With a clean and unobstructed cav-
ity, moisture which penetrates the face of the masonry runs down the back
of the veneer and is collected on the flashing and drained through weeps.

7.5 Flashing and Weep Holes

Full head and bed joints and good bond of mortar to units will min-
imize moisture penetration directly through the face of a masonry

Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.