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Add
Collectors
to
Strengthen
Floors/Roofs
Buildings
may be
damaged if
floor
and/or
roof
systems
cannot
transfer
shear
forces.
Collectors,
or drag
struts,
collect or
‘drag’
shear
forces
from
unsupported
areas of
the floor
or roof
systems to
the
load-bearing
walls. A
collector
is
composed
of a long
wood or
steel
member
that
extends
into the
floor or
roof
framing at
one end
and is
anchored
to
load-bearing
walls at
the other
end.
Effectiveness:
- Somewhat
to
very
effective.
Limitations:
- Effectiveness
limited
by
the
strength
and
configuration
of
the
building.
Strengthen
Floor/Roof
Systems
With Steel
Chords
Long
masonry
walls tend
to crack
and
collapse
due to
bending.
Damage may
be reduced
by
securing
the long
walls to
both the
floor and
roof by
using
either
chords
composed
of steel
straps or
continuous
steel
angles.
The straps
or angles
allow the
walls and
the floor
and roof
to act
like a
steel
I-beam,
increasing
the
strength
of the
floor, the
roof, and
the
building.
Effectiveness:
- Very
effective.
- Add
tension
ties
and
shear
anchors
to
increase
effectiveness.
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