U.S. patent number 3,672,108 [Application Number 05/065,351] was granted by the patent office on 1972-06-27 for joint construction.
This patent grant is currently assigned to United States Gypsum Company. Invention is credited to Donald J. Conway.
United States Patent |
3,672,108 |
Conway |
June 27, 1972 |
JOINT CONSTRUCTION
Abstract
A stucco-covered, curtain wall construction employs a joint
including an elongate L-shaped casing bead and an elongate
generally wing-shaped drainage cap member. The two joint components
form a horizontally-disposed, structurally yielding joint between
outer covering panel sections. The two joint components provide
ventilation and water drainage between the windward and leeward
sides of the wall.
Inventors: |
Conway; Donald J. (Glenview,
IL) |
Assignee: |
United States Gypsum Company
(Chicago, IL)
|
Family
ID: |
26745514 |
Appl.
No.: |
05/065,351 |
Filed: |
August 19, 1970 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
771821 |
Oct 30, 1968 |
3568391 |
Mar 9, 1971 |
|
|
Current U.S.
Class: |
52/367;
52/396.07 |
Current CPC
Class: |
E04B
1/7023 (20130101); E04B 2/94 (20130101); E04F
13/0801 (20130101); E04F 19/06 (20130101); E04F
19/061 (20130101) |
Current International
Class: |
E04B
2/94 (20060101); E04F 19/06 (20060101); E04B
2/90 (20060101); E04F 13/08 (20060101); E04F
19/02 (20060101); E04B 1/70 (20060101); E04b
001/70 (); E04f 013/06 () |
Field of
Search: |
;52/364,368,58,60,61,97,198,408,235,302,573,367,371 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Faw, Jr.; Price C.
Parent Case Text
RELATION TO PENDING APPLICATIONS
This application is a divisional application of my application Ser.
No. 771,821 filed on Oct. 30, 1968, now U.S. Pat. No. 3,568,391.
Claims
I claim:
1. A wall joint construction comprising a casing bead having a
grooved, substantially planar back integrally formed with a ledge
portion joined thereto at substantially right angles and adapted to
engage lower portions of a first mass of surfacing material; an
elongated drainage cap having upper and lower coplanar wings joined
by a flexible web connection of substantially V-shaped cross
section, the upper wing portion being disposed in surface contact
with a lower grooved portion of the casing bead back; the drainage
cap lower wing and a lower portion of the flexible web engaging the
rear surface and top edge portions respectively of a second mass of
surfacing material disposed beneath said first mass in
substantially coplanar relationship, the casing bead ledge portion
being movable with the first mass of of surfacing material and the
drainage cap lower web portion being movable with the second mass
of surfacing material whereby relative movement between the
surfacing masses in the vertical plane results in flexing of the
cap web.
2. The joint construction of claim 1 in which said casing bead
ledge portion has an upstanding flange and said drainage cap
flexible web has a depending lip; said flange and lip being in
substantially the same plane.
3. A wall joint construction comprising a casing bead having a back
integrally formed with ledge means along a line of juncture; said
ledge being adapted to engage a first section of wall surfacing,
drainage cap means having a back portion adapted to be supported by
a supporting surface, a downwardly disposed drainage means directly
connected to said back portion along a line of juncture and cap
means for engaging the upper edge portion of a second section of
wall surfacing, integrally formed with said drainage means and
resiliently movable relative thereto; said casing bead back having
a plurality of grooves formed in the rear surface thereof defining
open end, water-retaining passageways when said casing bead support
means-back juncture is nestably received in the juncture between
said drainage means and back portion of said drainage cap
means.
4. The wall joint construction of claim 3 in which said drainage
cap drainage means has a depending lip and said casing bead ledge
means has an upstanding flange; said lip and flange lying in
substantially the same plane.
5. The wall joint construction of claim 3 in which said passageways
are substantially uniform in cross section and have lengths between
about 2 and 6 inches.
6. The wall joint construction of claim 5 in which said grooves
have a cross-sectional width of the order of between 3/32 inch and
1/2 inch.
7. The wall joint construction of claim 3 in which a wall surfacing
material is supported as said ledge means, and means for keying
said surfacing material to said supporting surface is secured to
said supporting surface and embedded in said wall surfacing.
Description
BACKGROUND OF THE INVENTION
This invention relates to a water-shedding, expansible joint
structure for use in a stucco-covered, curtain type, generally
exterior wall. The term "curtain wall" is applied to a type of
building construction in which an exterior non-load bearing wall is
supported in front of the structural frame like a curtain. More
particularly, this invention relates to a casing bead and a
drainage cap or flashing in a ventilated curtain wall construction
providing water drainage and a degree of equalization of air
pressure between the wall cavity and the surrounding
atmosphere.
Curtain type, as well as some other exterior panel walls having an
exposure to rain driven by winds having a velocity as high as 90
miles per hour in certain areas of the United States, have been
vulnerable to admittance of wind-carried water as well as to
insufficient drainage of accumulated water from the cavity of the
wall, or the interval between the exterior wall and the inner,
supporting framing shell of the wall construction.
Oftentimes rain enters into the wall cavity wherever a joint line
has not been sealed, or adequately sealed, against ingress of rain.
Cracks, poorly designed joint lines or other types of leaky
constructions which open to the atmosphere allow for admittance of
water, and in many cases such constructions do not provide for
drainage of water from the cavity of the wall.
The problem of infiltrated water has become crucial where the
exposed wall area is large and vulnerable to rain driven by high
velocity winds. The problem often is aggravated in cases where the
water entering the wall cavity accumulates to a sufficient degree
to cause leakage into the interior of the building with resulting
damage. Such damage includes corrosion to metal parts, wetting and
compacting of insulation materials and damage to building interiors
and furnishings. Also, in some cases water entering the wall cavity
does not drain to the exterior of the building, but soaks down
through the wall portions causing structural deterioration and
discoloration to visible exterior portions of the wall.
Previously, in stucco as well as other types of curtain walls,
various attempts have been made to overcome this problem. Such
attempts have included high quality workmanship on existing
constructions, the use of sealants and weepholes, and pressure
equalization systems of various types.
In the normal use of the joint components provided by this
invention, an elongate wing-shaped drainage cap is horizontally
aligned on the exterior of a building frame or shell which may be
formed of plaster-board sheathing. The cap has a central, flexible
joint portion which serves as a drainage ledge and which is
V-shaped in cross section. The central V is integrally formed with
opposed coplanar wings, either or both of which may be fastened to
the sheathing.
A casing bead of generally L-shaped configuration is set in place
with the short leg of the L resting on the upper surface of the cap
joint portion. The back of the bead has a plurality of flutes or
grooves formed therein and extends above the upper wing of the
drainage cap. The bend is secured in place, and stucco or other
cementitious material may be formed into a panel over the sheathing
on the short leg of the bead which serves as a panel edging and
thickness gauge. Preformed panels may also be secured in place on
the bead leg. Water formed in or entering into the wall cavity may
readily drain to the exterior, through these grooves by gravity, as
will hereinafter be explained in detail. Also, water driven into
the joint between the cap and bead will be restrained or "baffled"
in the restricted groove portions and will not readily pass into
the wall cavity behind the panels.
It is an object of this invention, therefore, to provide a simple
and inexpensive casing bead and drainage cap joint construction
which is adapted to be disposed horizontally at the base of each
course of either stucco-covered wall sections or inlaid panel
sections to prevent entrance into the joint of wind-driven water,
while also providing drainage of condensation or other accumulated
moisture from the wall cavity to the exterior of the building.
It is another object of this invention to provide a novel joint
construction comprising a casing bead and drainage cap which
functions to provide partial equalization of air pressure between
the wall cavity and the exterior atmosphere. Such equalization
eliminates one of the major causes of water infiltration into a
wall, that is, a pressure differential between the cavity and the
exterior.
Another object of this invention is to provide a casing bead member
having water draining grooves or flutes formed in the rear surface
thereof and also incorporates therein a screeding lip flange for
the gauging of stucco which may be applied thereto.
It is a further object of this invention to provide a casing bead
member having a plurality of grooves or flutes of predetermined
height so as to provide for the development of hydrostatic pressure
by confined water columns. The columns oppose incoming water driven
between the joint components by the wind striking the exterior of
the casing wall construction; such grooves provide communication
from the cavity of the wall to the exterior of the wall.
Another object of this invention is to provide the combination of
an elongate casing bead member and an elongate drainage cap member
to be installed in relatively movable engagement whereby adjacent
sections of the curtain wall which are subjected to thermal or
structural stresses may move relatively to each other in the
vertical plane, such permissible movement obviating possible damage
to the sections of the curtain wall.
It is another object of this invention to provide for novel
joint-forming components in a casing wall construction which is
adaptable to be erected in either the vertical plane as is normal,
or planes inclined to the vertical if so desired.
The above, and other objects of this invention will become more
apparent from the following detailed description when read in the
light of the accompanying drawings and the appended claims.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view illustrating a casing bead
and drainage cap member illustrated in assembled relationship with
a portion of a stucco panel disposed in normal position on the
casing bead;
FIG. 2 is a fragmentary exploded view illustrating rear surface
portions of a casing bead and drainage cap provided by this
invention;
FIG. 3 is a fragmentary perspective view illustrating rear surface
portions of a casing bead and drainage cap in assembled
relationship with a fragment of a stucco panel formed thereon;
FIG. 4 is a fragmentary sectional view of the joint components
provided by this invention shown in normal assembled relationship
in a multi-storied construction;
FIG. 5 is a fragmentary perspective view of a modified casing bead
provided by this invention;
FIG. 6 is a perspective view of a clip member adapted to join
drainage cap members together in horizontal alignment;
FIG. 7 is a fragmentary sectional view illustrating the manner in
which a drainage cap and modified casing bead member may be
employed in conjunction with a building soffit; and
FIG. 8 is a fragmentary perspective view of a casing bead installed
in the foundation region of a building.
DESCRIPTION OF THE INVENTION
Referring now more particularly to FIG. 1, an exterior view is
therein depicted of a portion of a curtain wall. A joint is
illustrated in the wall which is formed by an upper casing bead 10
disposed in overlying relationship with a lower drainage cap 12.
The external curtain wall sections are composed of discrete
sections or sheets of stucco 14, each of which rests on a ledge 16
of a casing bead 10. In addition to ledge 16, each casing bead has
a back 18 which is affixed by suitable securing members to
supporting framing members such as gypsum board sheathing 20 or the
like. The latter sheathing is normally secured to spaced vertical
supports which may be wood or steel members which are readily
erected in place. The joint components 10 and 12 may also be
supportably attached directly to such vertical members (not
illustrated in FIG. 1).
Inasmuch as a curtain wall by definition comprises a building
construction in which exterior panels are non-load bearing but are
supported by an inner supporting framework, it will be seen from
FIG. 1 that the curtains or stucco sections 14 are disposed as a
curtain over the sheathing 20. The specific details of construction
of the casing bead 10 and the drainage cap 12 are more apparent
from FIG. 2. It will be noted from FIG. 2 that the back 18 of each
casing bead may have apertures 22 formed therein to facilitate
passage of a securing means such as nails 26 illustrated in FIG. 1.
The ledge 16 of each casing bead connects the back portion with a
terminal flange 28 disposed substantially parallel to the back 18
and extending in the same direction therewith from the interposed
ledge 16. Grooves or flutes 30, one of which is illustrated in FIG.
2, are arranged at regular intervals such as 3 inch intervals in
the back 18 of the casing bead 10.
In the normal course of erection, the first joint element to be
erected is the drainage cap 12. As will be seen from FIG. 2, the
cap 12 comprises an upper wing member 32 which is connected to a
lower wing member 34 by means of an interposed, V-shaped connecting
joint 36. The lower wing 34, while in parallel relationship with
the upper wing, need only have a height adequate to facilitate
mounting, and may be one-half the height of upper wing 32. The
V-shaped connecting portion of the drainage cap terminates in a
drip flange 38. Flange 38 is of U-shaped cross-sectional
configuration and comprises a continuation of an upper slanted web
and drainage surface 40 and a lower, substantially horizontally
disposed web portion 42. Drainage surface 40 is preferably inclined
at an angle of about 15.degree. or 20.degree. to the horizontal.
Fastener receiving apertures 44 may be disposed at regular
intervals in each of the wing portions 32 and 34 of the drainage
cap as is most clearly seen from FIG. 2.
In the course of joint construction, a drainage cap 12 is
horizontally aligned and secured in place to supporting frame
member such as the sheathing 20 shown in FIG. 1. The casing bead 10
is then supported on the upper web 40 of the drainage cap so that
the right-angle juncture between the back 18 and the horizontal
ledge 16 of the casing bead is nestably received in the juncture
between the upper wing 32 and the upper web portion 40 of the
drainage cap. The casing bead will now be disposed horizontally and
is fixed by suitable fasteners such as nails or the like to the
supporting framework. After the two joint components 10 and 12 are
fixedly secured in place, a formable cementitious material such as
stucco will be applied over the sheathing so that a sheet 14 will
be formed, resting upon ledge 16 of the casing bead as illustrated
in FIG. 1.
In order to secure firm engagement between each stucco panel 14 and
the opposed sheathing 20, an expanded metal mesh may be secured in
place against the sheathing and over back 18 of the casing bead by
clip members 48 or large head nails or other equivalent securing
means. The expanded metal layer 46 is adapted to function as means
for keying the stucco in which the mesh is embedded to the
supporting sheathing 20. To further assist in the keying action,
the expanded metal sheet 46 may be depressed out of a single plane
at regular intervals to further assure desired engagement with the
stucco material or other hardenable material. As will be noted from
FIG. 1, the thickness of the finished stucco panel 14 substantially
coincides with the width of the ledge 16 of the casing bead. As is
seen from the illustrated joint of FIG. 4, the upper edge portion
of each stucco panel may be formed between the rear surface 34 of a
drainage cap member and the opposed depending drip flange 38.
The spacing between the supporting ledge 16 of each casing bead and
the overlying lower web portion 42 of a drainage cap member
determines the height of each stucco panel 14 which is formed in
situ and employed in the illustrated type of curtain wall
construction. The specific dimensions of the panels employed for
forming the curtain wall are discretionary with the builder; a
typical stucco panel will have dimensions of 4 to 6 feet in height
and of 8, 10 or 12 feet in length. Each ledge 16 of each casing
bead may have centrally disposed drainage apertures 50 formed
therein at regular spaced intervals to assist in the drainage of
any water which may seep between the back 18 of the casing bead,
the ledge 16 and the stucco panel 14 which is formed thereover (see
FIGS. 1 and 3). The terminal flange or lip portion 28 of the casing
bead may function as a screeding member, as may the depending drip
flange 38 of an overlying drainage cap. Accordingly, after the
formable stucco or other cementitious composition is applied over
the back 18 of the casing bead and the overlying surface of the
sheathing, a smoothing or leveling instrument may employ the
depending and upstanding flange portions as screeds in forming the
appropriate thickness of each panel 14.
FIG. 3 illustrates the intended function of the drainage cap member
after the same has been erected in place in a curtain wall
construction. The upper drainage web 40 of each drainage cap 12 is
inclined to the horizontal at a slight angle. This slight angle
also functions to space the adjacent horizontal courses of the
stucco panels 14. The spacing between the panels is determined by
the magnitude of the divergence between the web portions 40 and 42
of each central V-shaped portion 36 of each drainage cap member.
Inasmuch as the web portions 40 and 42 of each V-shaped portion 36
may resiliently move relative to each other, upon the thermal
expansion of the cementitious material defining each panel in a
curtain wall, the same will be allowed to expand in the vertical
direction because of the spring or resiliency in the connecting
portion 36. Lateral expansion of panels 14 may be accommodated by
vertical framing members well known in the art, such as "I" beams
engaging panels between opposed flanges. Such structures are not
illustrated and comprise no portion of this invention.
The upper web portion 40 of each drainage cap in conjunction with
the undersurface of each ledge 16 of each casing bead defines an
exit way 37 for the vertical grooves 30 formed in the rear surfaces
18 of the casing beads. Assuming that a high velocity wind carrying
entrained water is blowing against the exterior cladding panels 14
of the curtain wall construction illustrated, water will be forced
into the V-shaped opening and rise in the grooves 30 formed in the
back of the casing bead member. The water columns in the grooves 30
will form hydrostatic heads opposing the force of the wind and
water blowing into the openings between adjacent, parallel panel
sections. The grooves 30 will serve as a means for equalizing the
pressure between the atmosphere on the exterior of the stucco
panels 14 and the interior cavity of the wall.
The grooves must have an effective cross-sectional area and
geometry to permit water drainage. If the cross-sectional area of
the groove is too small, inadequate drainage results. If the
cross-sectional area is too large, any water in the groove does not
maintain a sufficient continuity to provide a hydrostatic head
functioning as a floating damper to the wind blowing into the
openings between the panels or stucco sections.
Also, if the cross-sectional geometry of the grooves 30 possesses
constricted portions, surface tension of the water, or even
entrained dirt particles, is liable to restrict adequate and
desirable flow within the groove. Grooves of generally semicircular
configuration having a smooth wall trough in the configuration of a
V or an easy swept curve, and having a dimension of at least about
3/32 inch at the highest gapping have been found practical and
desirable. Maximum gappings of about 1/2 inch are contemplated by
this invention. Spacing between the grooves may vary; a simple
pattern of uniform spacing on 3 inch centers has been found to be
effective and practical.
By way of a specific example, a casing bead of the type shown in
the first four views of the drawing may have a lip flange 28 of
3/16 inch in height, a ledge 16 one inch in width and a back
portion of 6 3/8 inches in height.
Table I below indicates preferred relative dimensions between the
height of the back portion of a casing bead and the height of the
upper wing portion of an underlying drainage cap.
TABLE I
Casing Drainage Cap Bead Height Upper Wing Height
__________________________________________________________________________
43/8 Inches 21/2 Inches 53/8 Inches 31/2 Inches 63/8 Inches 41/2
Inches 73/8 Inches 51/2 Inches
__________________________________________________________________________
Utilizing certain data taken from Climatological Data, United
States Department of Commerce, Weather Bureau (1961), the following
Table II indicates the wind velocities effectively resisted by the
casing beads and drainage caps of Table I, the beads having flutes
of substantially uniform cross section.
TABLE II
Casing Bead Wind Static Semicircular Velocity Pressure Flutes Back
(MPH) (lb./sq.ft.) (Radius) Height
__________________________________________________________________________
40 4 3/64 In. 43/8 In. 60 9 3/64 In. 53/8 In. 75 14 3/64 In. 63/8
In. 90 20.2 3/64 In. 73/8 In.
__________________________________________________________________________
A modified drainage cap construction 10a is illustrated in FIG. 5.
Cap 10a has a concavity formed in the rear surface 18a thereof, the
rear surface being bent slightly along a middle axis 54. The slight
concavity enables a spring action to be effected when the casing
bead is secured in place against a supporting, planar sheathing
surface. Thus the modified casing bead construction 10a is assured
of secure, rattle-free engagement with the underlying sheathing
surface or surfaces upon being nailed in place.
Modified casing bead 10a also illustrates grooves 30a which are
slightly angled to the vertical so as to provide a more tortuous
path for any water which is driven between the casing bead and
underlying drainage cap. The groove portion 30a formed in the upper
portion of casing bead back 18a in FIG. 5 forms angles when joining
the lower groove portions 30a formed in the lower half portion of
the back 18a of the casing bead 10a. The concavity illustrated in
casing bead 10a may obviously be formed in casing bead 10 without
altering the vertical disposition of the grooves 30. Also, the
angled grooves 30a may be formed in a casing bead 10 having a
planar rear surface portion 18 without a concavity. The depth of
the concavity in the modified casing beads is fairly slight, being
in the nature of approximately 1/8 inch at its deepest point.
The casing bead and drainage cap constructions provided by this
invention are adaptable to a variety of uses. Thus, the casing bead
10 may be employed by itself at the floor line in a concrete course
or slab construction as illustrated in FIG. 8. The casing bead
having the cladding panel 14 provides communication between the
exterior atmosphere and the cavity of the wall by means of grooves
30, the casing bead 10 being secured directly to the slab 56 by
appropriate securing means.
The casing bead and drainage cap may also be employed for purposes
of ventilating a soffit construction as illustrated in FIG. 7. A
modified casing bead 13 is therein illustrated supported from a
roofing deck 58, and in conjunction with the underlying drainage
cap, forms a baffle member providing a ventilating opening into the
underlying soffit space formed in part by the framing member 60 and
soffit board 61.
FIG. 4 is illustrative of the casing bead and drainage cap provided
by this invention employed in a multi-storied construction in which
spandrel 62, defining the juncture between adjacent floor members,
supports a steel shelf angle 66 by means of suitable fasteners, not
illustrated. Sheathing 68 is secured to vertical supports 70 which
engage runner members 72 at opposed end portions; the runners in
turn engage the shelf angle. In addition to the illustrated casing
bead 10 and drainage cap 12, FIG. 4 also illustrates the
utilization of a flashing strip 74 which may be employed for
assisting the drainage of water from the cavity of the wall to the
exterior of the building by directing the flow of condensate or
other water onto the upper web portion 40 of the illustrated
drainage cap 12. The flashing 74 may be a strip of water-resistant
tar paper, or even deformable metal which is rust resistant.
FIG. 6 illustrates a splicing clip 76 which may be employed to
assure horizontal continuity and closure of drainage caps 12. Clips
76 have a U-shaped clip portion 78 adapted to nestably receive
adjacent portions of drip flanges 38 arranged in a horizontal
course. In normal use clips 76 are interposed between the casing
beads and drainage caps.
It is seen, therefore, that a novel joint construction has been
provided which is particularly adapted for use in curtain wall
constructions. The novel casing bead and drainage cap effect a
number of useful functions and may be employed in a number of
useful applications, as is obvious from the above description of
the constructions illustrated in the drawings.
The novel curtain wall joints enable water which is forced into the
cavity of the wall behind the exterior facing to readily drain
therefrom by gravity, and also enables any condensate formed in the
wall cavity to drain to the exterior of the wall without causing
any damage. The novel venting grooves formed in the rear surface of
the casing bead also function as a communicating path enabling
pressure to equalize between the exterior end interior cavity of
the curtain wall.
Although the foregoing description has been specific with respect
to stucco or other cementitious composition which is formed into
panels in situ and placed on the described casing bead members, it
should be appreciated that the above described joint components may
also be employed in conjunction with preformed panel members such
as cast cement slabs which may be fitted into place on the ledge of
the casing bead and fixed in place by means of grouting which
assures the establishment of a continuous seal between the
supporting casing bead and the inlaid members forming the panel
supported by the casing bead. The provided joint components may, of
course, be employed in a variety of structures not defining what is
technically a "curtain wall" construction. The materials of
composition for the components should be of adequate strength and
water resistant to serve the described purposes.
It is apparent from the foregoing description that a number of
modifications may be made in the construction above described. This
invention is to be limited only by the scope of the appended
claims.
* * * * *