Note: Descriptions are shown in the official language in which they were submitted.
CA 02835794 2013-12-06
INTERIOR WALL CAP FOR USE WITH AN EXTERIOR WALL OF A
BUILDING STRUCTURE
BACKGROUND
Buildings having an exterior façade primarily composed of glass typically
comprise
a non-loading bearing curtain wall which supports the glass. The curtain wall
typically
comprises an aluminum frame for supporting the glass comprising a series of
mullions for
anchoring the frame to the building structure and may also provide a place to
abut vertical
and/or horizontal building partitions (e.g. walls, floors/ceilings). The
mullions provide a
space between the building partitions and the glass which may result in
undesirable sound
transmission between partitioned spaces within the building. The mullion
material may
also contribute to the transmission of undesirable sound.
Conventional methods for minimizing sound transmission include adding mass to
the mullion or adding sound absorbing materials to the mullion, such as
filling the mullion
with insulation. Another method involves attaching a vibration isolation cover
to the
mullion face. In another example, a partition wall is cantilevered out to meet
the glass and
the partition wall is sealed with the glass using caulk.
These methods for minimizing sound transmission often require modifications
for
each building structure and typically do not provide the desired magnitude
decrease in
sound transmission. Methods such as cantilevering the partition wall out to
meet the glass
do not allow for differential movement between the building and the curtain
wall system,
which can result in tearing of the sealing caulk.
The space provided between the building partitions and the glass can also
result in
undesirable transmission of fire between partitioned spaces within the
building. Wall to
ceiling and wall to floor joints can be provided with fire-rated materials to
provide a fire
stop or break to safeguard against the spread of fire within adjacent spaces
of a building.
However, the systems used to provide fire-rated materials to wall to ceiling
and wall to
floor joints often do not work with a curtain wall structure and thus the
intersection
between the building partition and the glass can present a challenge in terms
of preventing
the spread of fire between adjacent spaces when a curtain wall is in use.
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BRIEF SUMMARY
According to one embodiment, the invention comprises a wall cap for an
interior
wall of a building structure, the building structure comprising at least one
exterior wall and
at least one interior wall, and a gap formed between the at least one interior
wall and the at
least one exterior wall, the wall cap comprising at least one elongated member
having a
first end configured for attachment to the at least one interior wall, and
having an outer
surface extending substantially across the gap, the underside of the elongated
member
defining a chamber with at least a portion of the interior wall. At least one
material is
disposed within the chamber having at least one characteristic which abates at
least one
undesirable physical property of the gap. When the at least one elongated
member is
mounted in cantilever fashion to a portion of the interior wall and
substantially fills the gap
between the interior wall and the corresponding exterior wall, the at least
one material
abates the at least one undesirable physical property of the gap.
According to another embodiment, the at least one material comprises at least
one
width of fire-rated material configured to abate the transmission of at least
one of flame,
heat and hot gases across the gap. The at least one width of fire-rated
material has a fire
rating of at least 1 hour. The fire-rated material can include a material that
increases in
volume when exposed to temperatures of about 300 F and above.
According to yet another embodiment, the at least one material comprises at
least
one width of sound-damping material configured to abate at least one of
transmission and
amplification of vibration across the gap. The sound-damping material can
comprise at
least one of an open cell foam, a melamine-based foam, mass loaded vinyl,
intumescent
foam and combinations thereof
According to another embodiment, the at least one material is adhesively
secured to
the underside of the elongated member, and the elongated member is mounted to
the at
least one interior wall by at least one fastener.
According to yet another embodiment, the at least one material comprises at
least
one first width of fire-rated material configured to abate the transmission of
at least one of
flame, heat and hot gases across the gap and at least one second width of
sound-damping
material configured to abate at least one of transmission and amplification of
vibration
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across the gap. The at least one first width of fire-rated material can
further comprise a
backing plate having an offset flange mounted to the at least one interior
wall. The
backing plate can comprise a continuous web of material extending generally
the
longitudinal length of the elongated member and receiving the first width of
fire-rated
material. The backing plate can also comprise a plurality of brackets which
retain the first
width of fire-rated material to the at least one interior wall. The second
width of sound-
damping material can be mounted to the underside of the elongated member. When
the
elongated member is mounted to the at least one interior wall, the elongated
member
covers the at least one first width of fire-rated material, whereby the wall
cap then provides
both fire and vibration abating characteristics to the gap.
According to yet another embodiment, the elongated member comprises a distal
outer surface in juxtaposition with the at least one exterior wall, and being
spaced a
distance from the at least one exterior wall, and further comprising at least
one gasket
disposed within the spaced distance between the distal outer surface of the
elongated
member and the at least one exterior wall, whereby the at least one gasket
provides a seal
between the elongated member at the at least one exterior wall.
According to another embodiment, the at least one characteristic of the at
least one
material abates a fire transmission property of the gap.
According to another embodiment, the at least on characteristic of the at
least one
material abates at least one of a vibration transmission and vibration
amplification property
of the gap.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
Figure 1 is a perspective view of a portion of a building having a curtain
wall, as is
known in the prior art.
Figure 2 is a partial cross-sectional view of the building structure and
curtain wall
of the prior art of Figure 1 taken along the line 2-2.
Figure 3 is a perspective view of a portion of the building of Figure 1 having
a
plurality of wall caps according to an embodiment of the invention
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Figure 4 is a perspective view of the wall cap of Figure 3 according to an
embodiment of the invention.
Figure 5 is a partial cross-sectional view of the wall cap of Figure 2 taken
along the
line 5-5 according to an embodiment of the invention.
Figure 6A is a partial cross-sectional view of the wall cap of Figure 5
installed with
a plurality of gaskets according to an embodiment of the invention.
Figure 6B is a partial cross-sectional view of the wall cap of Figure 5
installed with
a plurality of gaskets according to an embodiment of the invention.
Figure 7 is a is a partial cross-sectional view of the wall cap of Figure 6
installed on
one side of the mullion of Figure 2 according to an embodiment of the
invention.
Figure 8 is a partial cross-sectional view of a sound chamber test set-up.
Figure 9 is a partial cross-sectional view of a wall cap in use with the sound
chamber test set-up of Figure 8.
Figure 10 is a partial cross-sectional view of a building structure and wall
cap
according to an embodiment of the invention.
Figure 11 is a partial cross-sectional view of a building structure and wall
cap
according to an embodiment of the invention.
Figure 12 is a partial cross-sectional view of a building structure and a wall
cap
according to an embodiment of the invention.
Figure 13 is a partial cross-sectional view of a building structure and a wall
and a
wall cap having a fire rated assembly according to an embodiment of the
invention.
Figures 14A and 14B are partial cross-sectional views of a building structure
and a
wall cap having a fire rated assembly according to an embodiment of the
invention.
Figure 15 is partial perspective view of a fire rated material and bracket
according
to an embodiment of the invention.
Figure 16 is a partial cross-sectional view of a building structure and a wall
cap
having a fire rated assembly according to an embodiment of the invention.
Figure 17 is a partial cross-sectional view of a building structure and a wall
cap
having a fire rated assembly according to an embodiment of the invention.
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DETAILED DESCRIPTION
Figure 1 illustrates a portion of a building structure 12 having a plurality
of
partitions 20 forming multiple areas or rooms 13 within the building structure
12 and
having a curtain wall 10, as is known in the art. The curtain wall 10 shares
many features
of a traditional curtain wall, which will not be described in detail except as
necessary for a
complete understanding of the invention. As illustrated in Figure 1, the
curtain wall 10
forms an exterior or outer wall of the building structure 12. Curtain walls
are typically
non-structural walls that do not carry any load weight of the building, other
than its own
load weight, but rather form a façade of the building structure. A curtain
wall is typically
used to provide a building with an exterior wall formed of glass, for example.
While the
curtain wall 10 is illustrated as an exterior façade of the building structure
12, ribbon
windows and window walls might also be used for the facade of the building
structure. A
window wall can also be used as an interior partition wall for an area inside
the building
structure 12.
Figure 2 is a cross-sectional view of a portion of the curtain wall 10
anchored to the
building structure 12 that can be used with the embodiments of the invention
described
herein. The curtain wall 10 comprises mullion 14 which supports in-fills 16
that can be
made of glass, metal or thin stone, for example. The mullion 14 can be made
from any
suitable metal or metal alloy material, but is typically made of Aluminum. The
mullion 14
can abut a vertical partition, such as partition 20, and/or horizontal
partition, such as a
floor, of the building structure 12 as is known in the art. The exact manner
by which the
mullion 14 is anchored to the building structure 12 is not germane to the
invention. A
plurality of mullions 14 can be used to anchor a plurality of in-fills 16 to
the building
structure 12, as is known in the art.
The partition 20 can be a vertical partition (as shown in Figure 1), such as
an
interior wall or an exterior wall, or a horizontal partition (not shown), such
as a floor or
ceiling, for example. The partition 20 can include a first side 22, a second
side 24 and an
end 26 hung on a framing system comprising at least one stud 28. The stud 28
can be
made of wood, metal or metal alloy, and is typically made of steel. The
partition 20 can be
made of drywall, gypsum wallboard, sheet rock or plasterboard, for example,
and can have
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any suitable length depending on the architecture of the building. The
partition 20 can be
filled with any suitable type of insulation 30, such as fiberglass insulation,
as is known in
the art. The partition 20 can optionally also include resilient channel strips
31, that are
commonly installed with drywall to offset the drywall from the framing system.
Optional first and second trim pieces 32, 34 can be mounted on the partition
20
adjacent the mullion 14 for aesthetic reasons and can be made of the same
material and
have the same finish as the mullion 14. In one example, the first and second
trim pieces
32, 34 can be made of light gauge aluminum.
Figures 3 and 4 illustrate a wall cap 50, which can also be referred to as a
mullion
cap when used in combination with a mullion, according to an exemplary
embodiment of
the invention. The wall cap 50 can be used to abate a physical property of a
gap defined by
an exterior wall (e.g. the in-fill 16) and an interior wall (e.g. the
partition 20). Non-
limiting examples of a physical property of the gap include a vibration
transmission
property, a vibration amplification property and a fire transmission property.
Fire
transmission property can include the ability to transfer or allow the passage
of heat, flame
and/or hot gases. Vibration transmission and amplification can include the
ability to
transfer sound and/or amplify sound waves. As used herein, the term abate
refers to
lessening, reducing or removing a property.
The wall cap or mullion cap 50 can comprise an end cap 52 and a sound
insulating
material 54 installed with the building structure 12 of Figures 1 and 2. The
mullion cap 50
includes a first leg 56 and a second leg 58 extending from a first end of the
first leg 56.
The first leg 56 can include one or more apertures 60 for securing the mullion
cap 50 to a
structure. The end cap 52 can be made of any suitable metal, polymeric,
composite, metal
alloy or wood material and have any suitable color or finish to provide the
desired aesthetic
appearance. For example, the end cap 52 can be an aluminum extrusion that is
anodized or
painted to match the finish of the curtain wall 10 and mullion 14. The first
leg 56, the
second leg 58 and the adjacent portion of the partition 20 can define a sound-
receiving
chamber which is provided with sound insulating material 54 to dampen sound
and
vibration emanating from the building structure 12 before being transmitted to
the partition
20.
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The mullion cap 50 can have any suitable length depending on the parameters of
the structure in which the mullion cap 50 is being installed. For example, the
length of the
mullion cap 50 can be based on the height of the partition 20. The length of
the first leg 56
and second leg 58 can vary depending on the distance between the partition 20
and the
curtain wall 10 and the width of the partition 20, for example. It is also
within the scope of
the invention for the mullion cap 50 to not include the second leg 58.
The sound insulating material 54 can be any suitable material or layers of
material
for absorbing and deadening sound to provide a desired Sound Transmission
Class (STC)
rating. The STC is a single-number rating of a material's or an assembly's
ability to resist
airborne sound transfer at frequencies of 125-4000 Hz. In general, a higher
STC rating
blocks more noise from transmitting through a partition.
One example of a sound insulating material 54 is a multi-layer acoustical
composite barrier, such as Prospec Composite available from Pinta Acoustic
Inc., which
comprises a Hypalon coated willtec open-cell foam layer having a convoluted
surface
bonded to a mass loaded vinyl layer with a willtec decoupler layer. Additional
non-
limiting examples include batt or blanket insulation, melamine-based foam,
intumescent
foam, acoustic foam, mineral board, mass loaded vinyl, damping compounds and
combinations of different materials.
The sound insulating material 54 can be mounted to the end cap 52 using any
suitable mechanical or non-mechanical fasteners, non-limiting examples of
which include
screws, clips, snaps, clamps, adhesive and welds.
The mullion cap 50 can also include an optional trim piece 64 which can be
separate from the end cap 52 (Figure 4) or integrally formed with the end cap
52 (not
shown). When the trim piece 64 is not integrally formed with the end cap 52,
the trim
piece 64 can be secured to the mullion cap 50 and/or partition 20 any suitable
mechanical
or non-mechanical fasteners, such as screws or an adhesive, for example, or
the trim piece
64 can be configured as a snap-on piece.
Referring now to Figure 5, the first leg 56 of the end cap 52 can be secured
to the
partition 20 by fasteners 62 inserted through the apertures 60. The fasteners
62 can be any
suitable type of mechanical fastener, such as a bolt or screw, for example.
The fastener 62
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can extend through the partition wall 20 and optionally into the stud 28 such
that the
mullion cap 50 can be secured to both the partition 20 and any underlying
support structure
of the partition 20. The optional trim piece 64 can be secured over the
fasteners 62 in the
first leg 56 as part of the mullion cap 50. The trim cap 64 can have the same
color and/or
finish as the end cap 52.
While the mullion cap 50 is illustrated as being secured to the partition 20
using the
fasteners 62, it is within the scope of the invention for the mullion cap 50
to be secured to
the partition 20 using any suitable mechanical or non-mechanical fastener, non-
limiting
examples of which include screws, nails, adhesives, and/or double-sided tape.
The mullion cap 50 at least partially spans the distance from the partition 20
to the
in-fill 16 and extends into a gap 53 defined by the in-fill 16, the mullion 14
and the
partition end 26. The mullion cap 50 and sound insulating material 54 can
extend adjacent
to, but spaced from the mullion 14. In one example, the distance between the
sound
insulating material 54 of the mullion cap 50 and the mullion 14 is
approximately 1/8 of an
inch, although this distance can vary depending on the building structure and
in some
instances can range from 1/16 of an inch to 6 V2 inches. It is also within the
scope of the
invention for an outer surface of the sound insulating material 54 to be
adjacent to and in
contact with the mullion 14 along at least a portion of the mullion 14. It is
also within the
scope of the invention that the distance between the sound insulating material
54 of the
installed mullion cap 50 and the mullion 14 is small enough such that movement
and/or
settling of the curtain wall 10 and/or building structure 12 results in
contact between the
mullion 14 and the sound insulating material 54 that may or may not be
temporary.
As illustrated in Figure 5, the mullion cap 50 does not span the entire
distance from
the partition 20 to the in-fill 16, but is spaced from the in-fill 16 to allow
for differential
movement between the curtain wall 10 and the building structure 12. For
example, the
second leg 58 of the end cap 52 can be spaced approximately 1/16 to 1/4 of an
inch from the
in-fill 16. It is also within the scope of the invention that the distance
between the sound
second leg 58 of the end cap 52 and the in-fill 16 is small enough such that
movement
and/or settling of the curtain wall 10 and/or building structure 12 results in
contact between
the second leg 58 and the in-fill 16 that may or may not be temporary. The
mullion cap 50
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is anchored to the partition 20 such that the mullion cap cantilevers off of
the partition 20.
Even though movement and/or settling of the curtain wall 10 and/or building
structure 12
may result in contact of the mullion cap 50 with the in-fill 16 over time, the
mullion cap 50
is not supported by or anchored to the in-fill 16.
Referring now to Figures 6A and 6B, it is also within the scope of the
invention for
one or more gaskets or compressible seals 68a or 68b, such as a neoprene
gasket, closed
cell foam or other compressible gasket material, to be provided between the
second leg 58
of the end cap 52 and the in-fill 16. Multiple gaskets 68a can be used, as
illustrated in
Figure 6A, or a single, continuous gasket 68b can be provided, as illustrated
in Figure 6B.
While Figures 5 and 6A and B illustrate the use of the mullion cap 50 on both
sides
of the partition 20, it is also within the scope of the invention for the
mullion cap 50 to
only be used on a single side of the partition 20, as illustrated in Figure 7,
with gaskets
(Figure 7) or without gaskets 68 (not shown).
Optionally, acoustical sealant, such as OSI Acoustic /Sound Sealant, can be
used at
various joints within the system such as between the end cap 52 and the
partition 20,
between the mullion 14 and the partition 20 and between the mullion 14 and the
in-fill 16.
While the mullion cap 50 is illustrated as comprising an end cap 52 having a
first
leg 56 and a second leg 58, it is also within the scope of the invention for
the end cap 52 to
only comprise the first leg 56. For example, when used without the gasket 68,
the second
leg 58 may not be needed. When the gasket 68 is used with the mullion cap 50,
such as is
shown in Figure 6, the second leg 58 can provide a surface to which the gasket
68 can be
secured.
While the mullion cap 50 is described with respect to the curtain wall 10, the
mullion cap 50 can be used with any curtain wall or comparable building
structure, such as
a ribbon wall, strip windows, storefront, or other glass support systems, for
example.
Acoustical testing for a partition/curtain wall/mullion interface assembly
with and
without a mullion cap was determined in accordance with the following American
Society
for Testing and Materials (ASTM) standards: ASTM E 90-09, Standard Test Method
for
Laboratory Measurement of Airborne Sound Transmission Loss of Building
Partitions;
ASTM E 413-10, Classification for Rating Sound Insulation; ASTM E 1332-10a,
Standard
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Classification for Rating Outdoor-Indoor Sound Attenuation; ASTM E 2235-04,
Standard
Test Method for Determination of Decay Rates for Use in Sound Insulation Test
Methods.
Test Set-up Descriptions
The test equipment used to conduct the tests meet the requirements of ASTM E
90.
The microphones were calibrated before conducting sound transmission loss
tests.
Sound transmission loss tests were initially performed on a filler wall that
was
designed to test 48 inch by 72 inch and 72 inch by 48 inch specimens. The
filler wall is
described in more detail below in the description of Sample A. The filler wall
achieved an
STC rating of 69. A 48 inch by 72 inch plug was removed from the filler wall
assembly
and the sample was placed on an isolation pad in the test opening formed by
the removal of
the plug. Duct seal was used to seal the perimeter of the sample to the test
opening on both
sides. The interior side of the sample, when installed, was approximately VI
inch from
being flush with the receiving room side of the filler wall.
Sample A:
The test set-up for sample A is illustrated schematically in Figure 8. Figure
8
illustrates a partition/curtain wall/mullion interface assembly test set-up
comprising a
portion of a test curtain wall 210 and a test partition 220 similar to the
curtain wall 10 and
partition 20 of Figures 1 and 2 described above, except that the test curtain
wall 210
comprises a test mullion 214 coupled with a sound chamber wall 280 for
determining the
STC rating of the system instead of in-fills of glass or metal. Therefore,
elements of the
test curtain wall 210 and test partition 220 similar to those of the curtain
wall 10 and
partition 20 are labeled with the prefix 200.
The test partition 220 (filler wall) comprises a portion of a demising wall or
interior
wall consisting of a single 6 inch, 20 gauge steel stud wall with studs 228
spaced on 24
inch centers. One layer of 5/8 inch gypsum board 224 was fastened to the
vertical studs
228 on a receive side 282. On a source side 284, 25 gauge resilient channels
231 were
hung horizontally on the studs 228 (24 inch centers). One layer of 5/8 inch
gypsum board
222 was fastened to the resilient channels 286 on 24 inch centers. The cavity
of the test
partition 220 was insulated with 5 inch thick, 4 pounds per ft3 Thermafiber
mineral wool
insulation 230.
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A section of test mullion 214 was installed in a 5-5/16 inch wide by 72 inch
high
gap 300 between the test partition 220 and a sound chamber wall test opening
302. The
test mullion 214 was a box extrusion type made of aluminum, 5-5/16 inch by 72
inches by
2- 1/2 inch, having an extrusion wall thickness of 0.092 inches and weighing
1.74 pounds
per lineal foot. The test mullion 214 was sealed to the test opening 302 on
both sides using
an acoustic sealant. The test mullion 214 was not sealed to the test partition
220. Light
gauge aluminum trim 232, 234 was used to cap the area between the face of the
test
partition 220 and the test mullion 214 on both sides. The light gauge trim
232, 234 was an
"L" channel type made of Aluminum, 2- 15/16 inch by 72 inches by 1- 1/8 inch,
having a
material thickness of 0.053 inch and weighing 0.22 pounds per lineal foot.
Sample B:
The test set-up for sample B was similar to sample A except that the aluminum
trim
232, 234 was removed, and is illustrated schematically in Figure 9. An
exemplary mullion
cap 450 was installed on both sides of the test partition 220, extending
across the gap 300
adjacent the test mullion 214. The exemplary mullion cap 450 is similar to the
mullion cap
50 of Figures 3-7, therefore elements of the exemplary mullion cap 450 similar
to the
mullion cap 50 of Figures 3-7 are labeled with the prefix 400. The mullion
caps 450 were
fastened to the test partition 220 with drywall screws 462 and sealed using
acoustical
sealant. The mullion caps 450 were sealed to the vertical section of the test
opening 302
with 1/8 inch thick (1/16 inch compressed) neoprene gaskets 468 and sealed to
the test
opening 302 at the top and bottom with acoustical sealant. The mullion cap 450
comprises
an end cap 452 made of 0.130 inch thick aluminum and insulating material 454
comprising a 0.340 inch thick closed cell foam layer, a 0.085 inch thick mass
loaded vinyl
layer and a 0.670 inch thick closed cell foam layer. The mullion cap 450 had a
weight of
1.84 pounds per lineal foot and measured 6- 13/16 inch by 72 inches by 1- 1/2
inch. There
was a 7/8 inch (nominal) air gap between an interior face of the closed cell
foam and the
test mullion 214.
Sample C:
The test set-up for sample C was similar to sample B except that the mullion
cap
450 on the source side 284 of the test partition 220 was removed.
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Sample D:
The test set-up for sample D was similar to sample B except that the neoprene
gaskets 468 between the mullion caps 450 and the test opening 302 were
removed,
providing a 1/16 inch gap between the test opening 302 and the mullion caps
450.
Sample E:
The test set-up for sample E was similar to sample B except that there was a
3/16"
inch gap between the test opening 302 and the mullion caps 450 and 1/4" thick
(3/16"
compressed) neoprene gaskets 468 were used.
Sample F:
The test set-up for sample F was similar to sample B except that there was a
5/16"
inch gap between the test opening 302 and the mullion caps 450 and 3/8" thick
(5/16"
compressed) neoprene gaskets 468 were used.
Sample G:
The test set-up for sample G was similar to sample B except that there was a
5/16"
inch gap between the test opening 302 and the mullion caps 450 and the
neoprene gaskets
468 were replaced with Y2" thick (5/16" compressed) closed cell foam gaskets.
Table 1 below lists the STC and OITC results for Samples A-G. The STC rating
was calculated in accordance with ASTM E 413. The OITC (Outdoor-Indoor
Transmission Class) rating was calculated in accordance with ASTM E 1332.
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Table 1: STC and OITC Ratings for Mullion with and without Mullion Caps
Sample Description STC OITC
A Without mullion caps 28 28
Mullion caps on both sides 54 41
with 1/8" neoprene gasket
Mullion cap on one side with 51 41
gasket
Mullion cap on both sides 54 40
without gasket
Mullion caps on both sides 57 35
with 1/4" neoprene gasket
Mullion caps on both sides 57 36
with 3/8" neoprene gasket
Mullion caps on both sides 57 35
with 1/2" closed cell foam
gasket
As can be seen from the test results in Table 1, the use of the mullion cap
450
increases the STC rating of the test assembly from 28 to 57, meaning sound
transmission is
decreased when a mullion cap is installed. Even the use of a single mullion
cap on one
side of the mullion (sample C) decreases the sound transmission through the
test
partition/curtain wall/mullion interface assembly. As can be seen by comparing
the results
for samples B and E-G, the size of the gap between the wall cap and the
exterior wall and
the thickness and type of gasket used can be varied to provide a desired sound
rating and
differential movement between the curtain wall and interior partition walls.
Referring back to Figure 1, sound waves, illustrated schematically as waves
70, are
transmitted between rooms 13 through the mullions 14 and in-fills 16 of the
curtain wall
10. As illustrated by the test results, a typical demising wall, such as the
filler wall used in
the test set-up, can be provided with sufficient structure and insulation to
have an STC
rating of 69. An STC rating greater than 60 is generally considered to
correspond to
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enough sound proofing to render most sounds from an adjacent room inaudible.
However,
as illustrated by test sample A, a curtain wall system comprising a mullion
can have an
STC rating as low as 28. This is significantly less than the STC rating of the
adjacent wall
and generally low enough such that loud speech on the opposite side of the
wall can be
heard and possibly understood. Therefore, most of the sound transmitted
between rooms
13 in the building structure 12 is through the mullions 14 at the intersection
between the
exterior wall and the interior wall, not the partitions 20. In this manner,
building structures
utilizing curtain wall systems often have much lower overall STC ratings than
similar
building structures that do not utilize curtain wall systems. The transmission
of sound
between rooms in a building can be annoying and distracting to occupants and
can also
raise privacy issues.
As illustrated in Figure 3 and supported by the test data above, the use of a
wall
cap as described herein in a building structure having a curtain wall system
can
dramatically decrease the transmission of sound waves, illustrated as waves
72. The use of
the mullion cap 450 in the test set-ups B-G significantly increased the STC
rating of the
system from 28 to greater than 50. STC ratings above 50 are generally
considered to
correspond to loud sounds such as musical instruments or a stereo as being
faintly audible,
but not enough to bother the majority of the population. The use of the
mullion cap
described herein allows for the use of a curtain wall system without the
sacrifice in sound
attenuation normally ascribed to curtain wall systems.
Figure 10 illustrates a wall cap 550 which is similar to the wall cap 50
except for
the profile of the wall cap 550. The wall cap 550 can be used with a building
structure 512
which is similar to the building structure 12 except for the partition 520.
Therefore,
elements of the wall cap 550 and building structure 512 similar to those of
the wall cap 50
and building structure 12 will be numbered with the prefix 500.
Still referring to Figure 10, the building structure 512 includes a partition
520
which comprises an acoustic rated wall construction 600 and first and second
drywall sides
522 and 524 installed on an outside face of the acoustic rated wall
construction 600. The
wall cap 550 includes first leg 556 and a second leg 558 extending from the
first end of the
first leg 556. The second leg 558 is positioned adjacent the in-fills 516 when
installed with
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the building structure 512. The wall cap 550 further includes a third leg 602
at a second
end of the first leg 556, opposite the second leg 558. A fourth leg 604
extends from an end
of the third leg 602 opposite the end connected with the first leg 556, and is
generally
parallel to, but offset from, the first leg 556. The offset profile allows for
the wall cap 550
to be used when the partition 520 is offset from the center of the mullion
514, the width of
the partition 520 is not sufficient to accommodate the dimension of the second
leg 558, or
the width of the mullion 514 is too large to accommodate the dimension of the
second leg
558.
The wall caps 550 are secured to the acoustic rated wall construction 600
through
the fourth leg 604 using one or more fasteners 562 and cantilever out over the
mullion 514.
The first and second drywall sides 522 and 524 are installed such that the
drywall sides
522, 524 cover the fourth leg 604, with a distal end of the drywall sides 522,
524 generally
abutting the third leg 602 of the wall caps 550. As illustrated in Figure 10,
the length of
the third leg 602 is such that the first leg 556 of the wall caps 550 are not
flush with the
drywall sides 522, 524. Alternatively, the length of the third leg 602 can be
configured
such that the first leg 556 is generally flush with the drywall sides 522,
524.
Figure 11 illustrates another embodiment of the invention in which the wall
cap 50
is used with a building structure 712 and curtain wall 710. Therefore,
elements of the
building structure 712 and curtain wall 710 similar to those of the building
structure 12 and
curtain wall 10 will be labeled with the prefix 700.
The wall cap 50 can be secured to the building structure 712 in the same
manner as
described above with respect to the building structure 12. The wall cap 50 can
be installed
such that the wall cap 50 cantilevers off of the partition 720 and spans the
gap between the
end 726 of the partition 720 and the infill 716. The wall cap 50 can be
configured such
that the second leg 58 is positioned adjacent to the infill 716.
As illustrated in Figure 11, the wall cap 50 can be used to span the distance
between a partition and the adjacent infill even when no mullion is present.
The wall cap
50 can be used with a curtain wall, which is secured to the outside edge of a
building
frame, interior partitions, and storefront and window wall structures that are
formed within
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the perimeter of the building frame, with or without a mullion in a manner
similar to that
described above with respect to Figure 11.
Figure 12 illustrates another embodiment of the invention comprising the wall
cap
50 on one side of the partition and a wall cap 850, which is similar to the
wall cap 50
except for the shape of the end cap 852 on the other side of the partition
opposite the wall
cap 50. Therefore, elements in the wall cap 850 similar to those of the wall
cap 50 are
numbered with the prefix 800. The end cap 852 includes a first leg 856A, a
second leg
856B extending from a distal end of the first leg 856A and generally
orthogonal to the first
leg 856A, and a third leg 856C extending from a distal end of the second leg
856B and
generally parallel to and offset from the first leg 856A. A fourth leg 858
extends from a
distal end of the third leg 856C opposite the second leg 856B. The first leg
856A can
include one or more apertures (not shown) for securing the wall cap 850 to the
partition
820 by fasteners 862 inserted through the apertures in a manner similar to
that described
above with respect to the wall cap 50 of Figure 5 above.
The sound insulating material 854 can be mounted to the end cap 852 between
the
second leg 856B and the fourth leg 858 and adjacent the third leg 856C in a
manner similar
to that describe above for the sound insulating material 54 with respect to
Figures 3-5. An
optional separate or integral trim piece 864 can also be provided to conceal
the fasteners
862 and provide a desired aesthetic appearance. The wall cap 850 can also
include a
gasket 868 between the in-fill 816 and the fourth leg 858, similar to that
described above
for the wall cap 50.
As illustrated in Figure 12, the wall cap 850 can be used with building
structures in
which the mullion 814 is flush or nearly flush with one or both sides of the
partition 820.
The wall cap 850 can be used in combination with the wall cap 50, as
illustrated in Figure
12, when the mullion 814 is offset from one side of the partition 820. The
wall cap 850
can also be used on both sides of the partition, depending on the dimensions
and
configuration of the structure. The dimensions of the first, second, third and
fourth legs
856A-C and 858, respectively, of the wall cap 850 can be selected based on the
dimensions
of the relevant portions of the building structure, such as the offset of the
mullion from the
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partition and the distance between the interior and exterior elements of the
building
structure.
Figure 13 illustrates another embodiment of the invention in which the wall
cap 50
includes a fire rated assembly 900 to provide the wall cap 50 with a fire
rating. While the
fire rated assembly 900 is described in the context of the wall cap 50, it
will be understood
that the fire rated assembly 900 can be used with any of the wall caps
described herein.
The intersection where two-fire rated assemblies meet, for example a wall
assembly
and a floor/ceiling assembly, creates a joint through which flame and hot
gasses from fire
can spread. To prevent fire from spreading at this joint, fire rated
construction joint
assemblies are typically installed at these intersections. Many building codes
also require
that the gap at a curtain wall interface be treated to maintain the same fire
integrity and
protection as the adjacent floor and ceiling.
Various organizations on the national and international level have different
jurisdiction and influence on building codes and can use different terminology
and
standards related to fire integrity and protection, some of which may change
over time,
thus some background information may be useful. For example, in the United
States of
America, the National Fire Protection Association (NFPAO) defines a fire
rating as a
classification indicating in time (hours) the ability of a structure or
component to withstand
a standardized fire test. This classification does not necessarily reflect
performance of the
rated components in an actual fire, but rather is related to the performance
in a pre-
approved standardized test. A thermal barrier is defined as a material that
limits the
average temperature rise of an unexposed surface to not more than 250 F (139
C) for a
specified fire exposure complying with the standard time-temperature curve of
NFPA 251,
Standard Methods of Tests of Fire Resistance of Building Construction and
Materials, or
ASTM E 119, Standard Test Methods for Fire Tests of Building Construction and
Materials, based on the standards as of the filing date of this application.
The International Code Council (ICC) defines a fire protection rating as the
period
of time that an opening protective assembly will maintain the ability to
confine a fire as
determined by tests prescribed in Section 715 and is stated in hours or
minutes. Fire-
resistance rating is the period of time a building element, component or
assembly
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. . . -
maintains the ability to confine a fire, continues to perform a given
structural function, or
both, as determined by the tests, or the methods based on tests prescribed in
Section 703.
An f-rating is the time period that the through penetration firestop system
limits the spread
of fire through the penetration when tested in accordance with ASTM E 814
(ASTM
International). A t-rating is the time period that the penetration firestop
system, including
the penetrating item, limits the maximum temperature rise to 325 F (163 C)
above its
initial temperature through the penetration on the nonfire side when tested in
according
with ASTM E 814.
Thus, while the testing parameters and specifications can vary, in general,
the fire
integrity and protection properties of a material or structure are typically
quantified based
on the time a material or structure can withstand, confine and/or stop fire or
limit an
increase in temperature of a material or structure during exposure to fire.
The fire rated assembly 900 can include any material or combination of
materials to
provide the wall cap 50 with fire integrity and protection properties to
effect the fire
transmission properties at the intersection between the exterior partition and
the interior
partition. Non-limiting examples of suitable materials include firestopping
insulation, such
as a thermal ceramic insulation or fire batt insulation, fire rated mortar,
fire rated caulk, fire
rated gypsum material, vermiculite or perlite plaster products, and/or fire
rated expanding
foams or sealants, for example, that provide the desired fire rating.
Still referring to Figure 13, the fire rated assembly 900 can include a fire
rated
material 902 adjacent the sound insulation material 54, such as a fire rated
expanding
material, for example. One example of a suitable fire rated expanding material
is a fire
rated foam, such as a polyurethane or silicone based foam, that is provided
with an
intumescent material. An intumescent material is a material that swells or
expands and
increases in volume when exposed to heat. Non-limiting examples of intumescent
materials include graphite and sodium silicate based materials. At a
predetermined
temperature the intumescent material begins to expand on the fire side of the
joint. For
example, intumescent materials used in fire integrity and protection typically
begin to
expand around 300 F or above, although materials that begin to expand at
lower
temperatures can also be used. The expanded intumescent material can abate the
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. . . .
transmission of fire by absorbing heat and/or physically preventing the
passage of fire (e.g.
by filling or sealing the opening). Non-limiting examples of fire rated
expanding material
include SpecSeal Series intumescent inserts (Specified Technologies, Inc.,
U.S.A.),
Pyroplex8 Fire Rated Expanding Foam (Pyroplex Ltd., United Kingdom),
Sealmaster
FireFoam (Sealmaster, England) and 3MTm FireDamTM Intumescent Coating, Fire
Barrier
Sealant and Fire Barrier Pillows (3MTm, U.S.A.).
The fire rated material 902 can be adhered to the sound insulation material 54
continuously or discontinuously along the length of the sound insulating
material 54 using
any suitable mechanical or non-mechanical fastener, such as an adhesive, weld,
pins or
clamps. Alternatively, the fire rated material 902 can be formed as an
integral layer of the
sound insulating material 54.
Figures 14A and B illustrate a fire rated assembly 1000 that is similar to the
fire
rated assembly 900 except that the fire rated material 902 is mounted to a
backing plate
1002 which is secured to the partition 20 for supporting the fire rated
material 902 adjacent
the mullion 14 in the gap 53. The backing plate 1002 can be in the form of a
bent metal
plate having a first leg 1004 which can be secured to the partition 20 using
any suitable
fastener, a second leg 1006 extending from a distal end of the first leg 1004
and a third leg
1008 extending from a distal end of the a second leg 1006, opposite the first
leg 1004.
The length of the third leg 1008 can be selected so as to extend adjacent the
mullion 14 toward the in-fill 16 such that a gap is provided between a distal
end of the
third leg 1008 and the in-fill 16 to allow for deflection of the curtain wall
10 and
differential movement of the building structure. The backing plate 1002 can be
secured to
the partition 20 in a manner similar to that described for the wall cap 50
such that the
backing plate 1002 cantilevers off of the partition 20. When the backing plate
1002 is used
in combination with the wall cap 50, the trim piece 64 can be used to conceal
both the wall
cap fasteners 64, as described above, and the backing plate fasteners, which
may be the
same or different than the wall cap fasteners 64.
The fire rated expanding material 902 can include a first width 902a adjacent
the
second leg 1006 of the backing plate 1002 and a second width 902b adjacent the
third leg
1008 , as illustrated in Figure 14A or a single width of material 902 adjacent
the third leg
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. . . .
1008, as illustrated in Figure 14B. The fire rated material 902 can be secured
to the
backing plate 1002 using any suitable mechanical or non-mechanical fastener,
non-limiting
examples of which include adhesives, welds, pins, tacks, clips, clamps, snaps
and screws.
While Figures 14A and 14B illustrate the fire rated material 902 abutting the
sound
insulating material 54, it is also within the scope of the invention for the
fire rated material
902 to be spaced from the sound insulting material 54, such as by increasing
the length of
the second leg 1006 of the backing plate 1002.
Figures 14A and 14B illustrate the backing plate 1002 as a continuous web or
support plate extending substantially the height of the partition 20. In an
alternative
embodiment, illustrated in Figure 15, the backing plate can be discontinuous
in the form of
a plurality of brackets 1010, which have the same cross section as the backing
plate 1002,
comprising a first leg 1012 for securing the bracket 1010 to the partition, a
second leg 1014
and a third leg 1016 for mounting the fire rated material 902 in a manner
similar to that
described above for the backing plate 1002.
While the fire rated assemblies 900 and 1000 are described in the context of a
fire
rated material 902 in the form of an expanding fire rated material, it will be
understood that
the fire rated assemblies 900 and 1000 can be used with any other suitable
type of fire
rated material or combination of fire rated materials in a similar manner, non-
limiting
examples of which include firestopping insulation, such as a thermal ceramic
insulation or
fire batt insulation, fire rated mortar, fire rated caulk, fire rated gypsum
material,
vermiculite or perlite plaster products, and/or fire rated expanding foams or
sealants.
While the fire rated assemblies 900 and 1000 are illustrated and described in
the
context of the wall cap 50, it will be understood that the fire rated
assemblies 900 and 1000
can be used with any of the wall caps described herein in a similar manner. In
addition,
while the fire rated assemblies 900 and 1000 are illustrated as being used
with a wall cap
50 including a compressible gasket 68B, it will be understood that fire rated
assemblies
900 and 1000 can be used with or without a gasket. In addition, the fire rated
assemblies
900 and 1000 can include additional fire rated materials in combination with
the fire rated
material 902 to provide the desired fire rating at the junction between the
interior and
exterior walls.
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. . . .
In addition, while the fire rated assemblies 900 and 1000 are described in the
context of a wall cap 50 having sound insulating material 54 to provide
vibration abating,
it is also within the context of the invention for the fire rated assemblies
900 and 1000 to
be used with a wall cap that does not include sound insulating material. Using
the fire
rated assemblies 900 and 1000 without the sound insulating material 54 can
provide
additional space for using thicker or bulkier fire rated materials,
alternative fire rated
materials or combinations of fire rated materials. For example, intumescent
foam typically
has a thinner profile than other materials, such as fire batt insulation, and
thus requires less
space. However, intumescent material can be more expensive than some other
materials.
Removing the sound insulating material 54 from the wall cap 50 provides more
space
within the wall cap 50 for using alternative materials that require more space
than
intumescent foams and/or combinations of materials to provide a desired fire
rating.
For example, as illustrated in Figure 16, the fire rated assembly 900 can be
used
with the wall cap 50, as illustrated in Figure 13, without the sound
insulating material 54
and with a thicker layer of fire rated material 902. The fire rated material
902 can be
attached to the wall cap 50 using any suitable mechanical or non-mechanical
fasteners,
non-limiting examples of which include screws, clamps, clips, adhesives and
welds.
Figure 17 illustrates another example in which the fire rated assembly 1000 is
used with
the wall cap 50, similar to that illustrated in Figure 14B, except for the
sound insulating
material 54 has been removed, providing additional space to use a thicker
layer of fire
rated material 902 on the backing plate 1002.
It is also within the scope of the invention for the wall cap 50 and either of
the fire
rated assemblies 900 and 1000 to be provided with one or more materials that
provide both
vibration and fire abating properties. It will also be understood that
depending on the
materials used with the wall cap 50, the sound insulating material 54 can
contribute to the
fire abating properties of the wall cap 50 and the fire rated material 902 can
contribute to
the vibration abating properties without deviating from the scope of the
invention.
In use, in the exemplary embodiment of a fire rated intumescent material, when
the
temperature of the material reaches a predetermined temperature, the
intumescent foam can
expand and at least partially fill the gap 53, thus abating the ability of
fire, in the form of
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flame, heat and/or gas, to transfer through the gap 53 to the opposite side of
the partition
20. In this manner, the intersection between the in-fill 16 and the partition
20 can be
provided with a fire resistance rating corresponding to the fire resistance
rating of the
adjacent wall structure. Many building codes require that the gap at a curtain
wall be
treated so as to maintain the same fire integrity as the adjacent partition
wall. When used
with either the backing plate 1002 or brackets 1010, the backing plate 1002
and brackets
1010 provide support for the fire rated expanding material 902 before the
material has
expanded and also supports the resulting expanded material or char that forms
during a fire
event. Supporting the expanded material or char can contribute to providing
the wall cap
50 with the desired fire rating.
The wall cap 50 can be used with any of the fire rated assemblies 900 or 1000
to
provide a wall cap 50 that abates vibration and/or fire transmission
properties of the gap 53
between an interior and exterior wall. The wall cap 50 in combination with the
fire rated
assembly 900 or 1000 can provide a first width of material that can absorb
vibrations to
abate both vibration transmission and amplification across the gap 53 between
adjacent
rooms. The fire rated material 902 provided by the fire rated assemblies 900
and 1000 can
provide the wall cap 50 with a second width of material that abates fire
transmission across
the gap 53, thus providing fire integrity and protection at the junction
between an interior
wall (e.g. partition 20) and an exterior wall (e.g. in-fill 16) to stop or
delay the spread of
fire and/or transfer of heat between adjacent rooms. The wall cap 50 can also
be used as
described above to separately provide vibration abating without the use of the
fire rated
assemblies 900 and 1000 or to provide fire abating without the use of the
sound insulating
material 54.
The wall cap described herein provides an aesthetically appealing and durable
system for abating vibration transmission and amplification and fire
transmission through
building partitions at the exterior perimeter or interior of a building having
a curtain wall,
window wall, ribbon window, or any wall system that utilizes a hollow tube
framing
system. The wall caps can be provided in a variety of colors and finishes to
provide a
desired aesthetic appearance. The wall caps can be assembled, packaged and
shipped to
the building site for installation and can easily be trimmed to the desired
length and to fit
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around horizontal mullions, stepped sills or other obstructions on-site. The
wall caps can
be installed during building construction or retrofitted to existing
structures and can be
used with most curtain wall systems. In addition, when installed, the wall
caps can be
spaced from the mullion, thus allowing for differential movement between the
building
structure and the curtain wall system.
Because the wall cap cantilevers off of an adjacent partition and is not
mounted to
the mullion or the in-fill, the wall cap can be configured for use in a
variety of different
situations in which a partition terminates at a curtain wall, glass store
front, window wall
and/or interior glass partition, with or without a mullion. The wall cap can
be used to abate
vibration transmission and amplification and fire transmission between
adjacent partitioned
spaces regardless of whether the wall cap encompasses a mullion. This may be
the case
when a mullion system is not in use or when the partition terminates at a
location not
adjacent to a mullion. This provides the builder with added flexibility in
designing and
constructing spaces.
The wall cap also acts as a trim piece that conceals and trims the end of the
partition which the wall cap cantilevers off of For example, when the wall cap
is used
with a drywall partition, such as that shown in Figure 2, the trim pieces 32
and 34 are not
necessary. In this manner the wall cap provides both a functional benefit in
that the
transmission of sound through the mullion is decreased and an aesthetic
benefit in that
additional trim pieces are not needed.
The 2009 International Building Code requires demising walls of multi-family
dwellings to have an STC rating of SO. The 2010 Guidelines for Design and
Construction
of Health Care Facilities has design criteria of a minimum STC rating of 45
between
patient rooms and a minimum STC rating of 50 between intensive care rooms. As
evidenced by the test data of Table 1, traditional curtain wall assemblies are
unable to
satisfy these requirements. The wall cap described herein provides an
economical and easy
to install system that is able to satisfy the 2009 International Building Code
and the 2010
Guidelines for Design and Construction of Health Care Facilities requirements
that can be
installed during construction or retrofitted to existing structures. The
insulation material
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. . . .
provided with the wall caps can be selected based on the desired STC rating
while taking
budget concerns into consideration.
The wall cap further provided with the fire rated assemblies described herein
can
also provide a system to satisfy building codes for fire ratings. One example
of such a
building code is section 715 of the International Building Code, which
includes
requirements for mullions to provide the same fire resistance rating as
required for the
adjacent wall construction. The fire rated assemblies disclosed herein can be
used in new
construction as well as retro-fitted to existing structures to provide a fire
rating to meet or
exceed fire rating standards for building codes. In addition, the wall cap and
fire rated
assemblies can be used with various fire rated materials and combinations of
fire rated
materials to satisfy building codes that can vary depending on the location of
the building
structure and the agencies and groups which have jurisdiction over the fire
requirements at
that location. The wall cap and fire rated assemblies can further be updated
or retrofitted
to existing building structures as building codes and fire requirements
change. For
example, as new or improved materials for withstanding fire or providing a
thermal barrier
become available, these materials can be retrofitted to existing building
structures to
improve the fire rating or to maintain compliance with new regulations.
To the extent not already described, the different features and structures of
the
various embodiments may be used in combination with each other as desired.
That one
feature may not be illustrated in all of the embodiments is not meant to be
construed that it
cannot be, but is done for brevity of description. Thus, the various features
of the different
embodiments may be mixed and matched as desired to form new embodiments,
whether or
not the new embodiments are expressly disclosed.
While the invention has been specifically described in connection with certain
specific embodiments thereof, it is to be understood that this is by way of
illustration and
not of limitation. The scope of the claims should not be limited by particular
embodiments
set forth herein, but should be construed in a manner consistent with the
specification as a
whole.
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