Page 256 - Masonry and Concrete

Masonry Veneer

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MASONRY VENEER

ter vertically. In Seismic Zones 3 and 4, veneer anchors must also be
mechanically attached to continuous horizontal reinforcement of
9-gauge wire (W1.7). Special seismic anchors are made for such appli-
cations (Figure 7-6). Lap splices in the wire reinforcement should
occur between veneer anchors. Some manufacturers also make prefab-
ricated joint reinforcement with adjustable seismic veneer anchors for
block walls with brick veneer.

7.2 Veneer Support Above Grade

Where a portion of a masonry veneer wall occurs over a lower roof area
or balcony, support can be provided in one of two ways. The Code
requires that a steel angle be installed to carry the masonry and that
the angle either be attached to and supported by the stud frame, or
resting on framing members sized to carry the additional load with a
1
maximum deflection of 600 of the span (Figure 7-7). The masonry
should not rest directly on the wood framing or sheathing. Where
veneer supported above grade adjoins masonry supported on the foun-
dation, a control or expansion joint is required to prevent cracking
caused by differential movement. If the masonry is above a sloping
roof, the supporting angles may be attached to the studs as a series of
short sections which step down the slope. Masonry installed on a slop-
ing angle must be leveled with a mortar bed and will not be as stable.

7.3 Lintels and Arches

Noncombustible lintels of steel, reinforced masonry, stone, concrete,
precast concrete, and cast stone are typically used to span openings in
masonry veneer walls. Masonry arches perform the same function of
supporting the masonry above the opening and transferring the weight
to the wall sections on either side. Arches carry loads in compression,
but lintels act as flexural members spanning horizontally from one
support to the other (Figure 7-8). Lintels must resist compressive,
bending, and shear stresses (Figure 7-9). Lintels and arches must be
analyzed to determine the loads which must be carried and the result-
ing stresses which will be created in the member. Many of the cracks
that appear over door and window openings result from excessive
deflection of lintels which have been improperly or inadequately

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