Page 126 - Masonry and Concrete

Understanding Masonry
125
UNDERSTANDING MASONRY

4.7 Masonry Accessories

Some types of masonry construction require accessory items such as
anchors, ties, flashing, and reinforcement which are as important to
the successful performance of the masonry as the units and mortar
themselves.

4.7.1 Anchors, Ties, and Fasteners

Anchors are used to connect a masonry veneer to a backing wall of
some other type of construction such as wood framing, metal studs, or
concrete. The most common masonry anchor used in residential work
is the corrugated veneer anchor which can be nailed into wood studs
or screwed into metal studs (Figure 4-27). Wire anchors for attachment
to metal stud framing must be a minimum of 9 gauge. In areas with
high earthquake risk, building codes usually require special seismic
veneer anchors.
Ties are used to connect different wythes of masonry in a multi-
wythe wall. A corrugated veneer anchor can be used as a multiwythe
wall tie if it is laid flat in the bed joints, or stronger wire ties can be
used. A Z-shaped wire tie is used for solid masonry units such as
brick, and a rectangular wire tie is used for hollow masonry units such
as concrete block. Corrugated metal ties are less expensive than wire
ties, but they have to be spaced closer together, so more are needed.
Fasteners are used to connect other materials or objects to masonry
walls and may be designed to insert into a mortar joint or penetrate
through to a hollow core or cavity (Figure 4-28).
Wire ties for multiwythe walls must be 3/16-in. diameter. Corru-
gated anchors for residential work should be 7/8 in. wide and 22-gauge
thickness. Wire anchors should be a minimum of 9 gauge. For extra
protection against corrosion, use anchors and ties that are hot-dip gal-
vanized.

4.7.2 Reinforcement
Like concrete, masonry requires the incorporation of steel reinforce-
ment to increase flexural and tensile strength, and concrete masonry
uses steel reinforcement to resist moisture shrinkage. There are two
types of masonry reinforcement, prefabricated wire joint reinforce-
ment and structural reinforcing bars. Prefabricated wire joint rein-

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