US3707818A

US3707818A - Shaft cavity wall and stud

Info

Publication number: US3707818A
Application number: US00091338A
Authority: US
Inventors: N Nelsson
Original assignee: United States Gypsum Co
Current assignee: United States Gypsum Co
Priority date: 1970-11-20
Filing date: 1970-11-10
Publication date: 1973-01-02
Anticipated expiration: 1990-01-02
Also published as: AU473743B2; AU3600671A; CA970125A

Abstract

A cavity wall and stud wherein the stud is characterized by a base exposed to the corridor, and two side flanges which penetrate into the wall and thereafter diverge without closing upon themselves or each other, the ends of the flanges being used to anchor the facing layer of the wall. Resiliency can be introduced into the flanges to reduce sound transmission.

Description

O Unlted States Patent [191 [111 3,707,818 Nelsson 1 Jan. 2, 1973 [541 SHAFT CAVITY WALL AND STUD 2,123,410 7/1938 Fawcett 52/495 3,333,390 8/1967 Banning... ...52/48l X [75] Inventor 'i Des names 3,349,535 10/1967 Balinski ..s2 220 [73] gmg m Cmnmy FOREIGN PATENTS OR APPLICATIONS Fied Nov 10 1970 149,361 12/1952 Australia ..52/481 [21] Appl. No.: 91,338 Primary Exa'rniner-Price C. Faw, Jr.

Attorney-George E. Verhage, John Kenneth Wise d D M. S h 52 us. c1. .52/220, 52/30, 52/48], c

52/489 57 ABSTRACT [51] Int. Cl. ..E04b 2/28, 1504b 2/78 I [58] Field of Search ..52/48l,495, 173, 303, 30, A and Stud Wherem the Stud r 52/488 285 479 480 220 terized by a base exposed to the corridor, and two side flanges which penetrate into the wall and thereafter diverge without closing upon themselves or each [56] References Cited other, the ends of the flanges being used to anchor the UNITED STATES PATENTS facing layer of the wall. Resiliency can be introduced into the flanges to reduce sound transmission. 1,885,330 11/1932 Cherdron et a1 ..52/285 X 2,101,952 12/1937 Olsen ..52/349 X 9 Claims, 5 Drawing Figures SHAFT (IAVITY WALL AND STUD BACKGROUND OF THE INVENTION In recent years there has been a great demand for structural systems for enclosing open shafts in multistory buildings such as offices and high-rise apartments. Typical of such open shafts are air return shafts, elevator shafts, stairwell shafts and the like. The walls enclosing such shafts commonly separate the shafts from other rooms such as corridors, toilets, and utility rooms. With increasing governmental concern for promoting safety for occupants of public buildings, manufacturers of building products have sought to provide shaft walls meeting at least minimal safety requirements, while at the same time, providing builders with Two of the most important of these safety requirements concern wind loading and fire ratings. Destructive wind loading is of particular concern where the shaft is an air return shaft or an elevator shaft, where pressures or vacuums are developed which load the shaft wall up to fifteen pounds per square foot in excess of atmospheric pressure. Fire ratings of up to two hours are necessary, particularly with regard to transmissions from the shaft outwardly, as a fire in a shaft is otherwise easily transmitted from floor to floor of the entire building. Commonly, these safety requirements have required a construction which could be erected only as a finished wall, whereas construction techniques now require initially only that the shaftsbe enclosed to prevent men and materials from falling thereinto. The finishing of the shaft walls is preferably done later floor by floor as the building is completed.

The above fire problems concerning shafts can also be said to apply to long corridors in buildings, which in effect are horizontal, rather than vertical, shafts. Thus, without adequate fire ratings, a corridor wall easily transmits the fire throughout the building as the fire proceeds through the corridor.

Similar destructive wind loading occurs also on exterior curtain walls. Unless expensive scaffolding is used, these walls require the construction to be done all from the interior side of the wall. These walls must experience up to 30 psf pressure in excess of atmospheric pressure.

To solve these and other problems, early wind loaded walls such as shaft walls were commonly built up with and lined with various types of block masonry, including both concrete and gypsum block. While this block masonry has proved suitable for many applications, it has been found to be undesirable in those situations where the shaft rises to great heights. Because of their great weight, concrete block masonry materials require supporting structures of great weight and strength. Further, these heavy materials give rise to problems in their installation. Those skilled in installing the above described shaft lining materials are forced to handle at high levels the dangerously heavy concrete materials.

The next step in the construction of wind loaded walls was to substitute partition members for the block masonry. However, such constructions invariably joined several rows of partition members back to back to form a solid wall to insure that the required fire rating and wind loading were obtained. In some cases, members were laminated together to provide a partition member at least two inches thick. Such laminations not only required extra and expensive assembly steps, either at the factory or site, but resulted in members so heavy that extra men were needed to handle them and special cutting techniques were required to cut the members to size. A further disadvantage has been that some partition member elevator shaft walls constructed from panels such as drywall could be assembled only by positioning workmen and/or equipment within the elevator shafts-a procedure difficult at best and dangerous at worst.

The most recent panel type of wind loaded walls have been characterized by solid constructions, the

consensus generally being that such a construction is better suited to meet the stringent fire ratings and wind loadings. However, in addition to the problems recited in the previous paragraph, such solid construction results in increased material costs for a wall of a prescribed thickness, and the need for separate and thus expensive enclosures for raceways, electrical conduits, and the like.

Commonly owned U. S. Pat. application Ser. No. 90,504 filed on Nov. 18, 1970 describes one solution to the above problems. That solution features a windloaded shaft wall having a channel stud having a base and side flanges, the side flanges generally opening out into the shaft. These flanges are generally free to open apart under fire conditions, thus exposing the base, which is adjacent the facing layer of the wall, to the fire.

SUMMARY OF THE INVENTION The disclosure relates to an air shaft cavity wall and the stud used to assemble the same wherein the base of the stud is exposed to the shaft and the side flanges extend into the wall. As the base is imperforate, there is no opportunity for fire to penetrate into the wall to a point adjacent the facing layer. More specifically, there is provided an air shaft cavity wall enclosing an air shaft in a building subjected to air pressures, the wall including a plurality of studs and two rows of partition members spaced apart by the studs, the studs being characterized by an imperforate base, two side flanges, and means for engaging two of the members of one row on three vertical sides thereof, each of the bases extending out into the shaft and each of the flanges extending into the wall away from the shaft between the engaged members. An improved stud for use in a cavity wall, such as an air shaft wall, is also provided, the improvements concerning the fastening of the side flanges to the facing row of partition members and the bending of the side flanges so as to extend away from each other or themselves in a way which would render the interior of the stud inaccessible from the exterior.

Accordingly, it is an object of the invention to provide a two-flanged stud for a cavity wall which stud is anchored to the wall by means of the two flanges and at the same time is capable of being cut by a flying shear.

It is a related object of the invention to provide such a stud and cavity wall which resists pressure loading from the exterior side of the wall to which the stud is exposed.

Another object of the invention is to provide such a stud and wall which are fire-rated.

It is a further object of the invention to provide such a stud and wall with improved sound attenuation.

Other objects and advantages will become apparent upon reference to the following drawings and detailed discussion.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary side elevational view in section of a shaft and shaft wall constructed in accordance with the invention;

FIG. 2 is a fragmentary plan view in section of a portion of the wall shown in FIG. 1;

FIGS. 3 and 4 fragmentary plan views in section similar to FIG. 2 but illustrating alternate embodiments; and

FIG. 5 is a fragmentary plan view in section of still another alternate embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention pertains to wind-loaded walls in buildings, such as shaft walls which include walls enclosing stair wells, smoke shafts, horizontal shafts more commonly known as corridors, and particularly air shaft walls such as enclose air returns and elevator shafts. As used throughout this application, air shaft wall means a wall which must withstand at least up to psf pressure in excess of atmospheric pressure, such as is commonly experienced in air return shafts and elevator shafts, without collapsing or otherwise failing due to such a pressure loading.

Thus, as shown in FIG. 1 an air shaft 12 is enclosed in a building by

walls

14 and 16. For simplicity, the shaft 12 will be specifically described as an elevator shaft, the alternatives having been noted above. Thus, elevator cables 18 serve to raise and lower an elevator car (not shown) conventionally between the

walls

14 and 16. The wall 14 may be a conventional structure, but it preferably is identical to the wall 16. The walls 14 sand 16 conventionally extend only the height of each story of the building, being separated by floors and ceilings 20, the walls thus separating the shaft 12 from rooms 22, which may be corridors, toilets, and the like. The shaft thus extends continuously through the floors and ceilings, here shown as comprising at least three stories.

The wall 16 comprises floor and ceiling runners 24, two rows of partition members, a plurality of liner members 30 defining one of the rows one side 32 of which is exposed to the shaft 12, studs 70 holding the liner members in place within the runners 24, and partition members 50 spaced away from the liner members 30 by the studs and defining the other of the two rows. By means of the construction of these parts, the wall 16 is assembled entirely from the rooms 22, without placing men or equipment in the shaft 12. During this assembly the liner members 30 along with the studs 70 serve as a temporary wall in the initial stages of construction of the building to wall off the elevator shaft 12 without the need for additional barricades or safeguards.

Turning now to FIGS. 1 and 2, the details of the shaft wall 16 will now be discussed. The runners 24 are conventional metal runners attached to the floor and ceiling. Because the

flanges

26 and 28 thereof are of unequal width, the runners have a cross-sectional shape (FIG. 1) which resembles a J. The attachment of the runners positions the longer arm 26 on the shaft side of the wall 16.

The liner members 30 are panel members comprising individual drywall or wallboard panels preferably one inch thick, vertically positioned within the runners and having any type of composition such as gypsum or mineral fibers. Preferably, the panels are nonlaminated gypsum wallboard coated on both

sides

32 and 34 with a water repellant paper. The

vertical edges

36 and 38 of the liner members may also be paper coated. By non-laminated," it is meant a board cast as a single piece without a paper layer separating portions thereof longitudinally. The liners are held in place within the runners 24 solely by means of the studs 70, which themselves are snugly fit into the runners and engage snugly the

edges

36 and 38 of adjacent members 30. The studs are preferably either 16 inches or 24 inches on center. More particularly, each stud engages adjacent pairs of members 30 on the three sides of each member in the pair, the three sides being the opposing

sides

32 and 34, and either edge 36 or 38 (FIG. 2).

Turning now to the partition members 50, these comprise (FIG. 2) wallboard members or plaster layers which may be erected as a single layer or as two layers or rows which are in contact back-to-back. A single such member, such as would be the case if plaster is used, can comprise the portion of the wall which faces out intothe room 22. Or, a layer of plaster can be coated over a layer of wallboard members which form the base. Preferably, however, the construction utilizes two

layers

52 and 60 of gypsum wallboard. Layer 52 comprises wallboard members 54 horizontally laid against the studs end 56 to end 56, the wall-board members 54 being preferably covered with backing paper on both sides thereof. Layer 60 comprises wallboard members 62 preferably finished on side 64 with the desired interior finish, the members 62 being vertically mounted edge 66 to edge 66 against layer 52 so as to stagger the edges 66 from the ends 56. The horizontal arrangement of members 54 and the vertical placement of members 62 is essential for maximum fire rating, while permitting long length to be used in layer 52. The

layers

52 and 60 are held in place against the studs and runners, and against each other, by attaching means such as screws 68, which penetrate into the stud (FIG. 4). Screws 68 are also preferably used (not shown) to attach the layer 60 to the legs 28 (FIG. 1) at points spaced between the studs 70, to help hold the partition members 50 in place under conditions of fire.

Turning now to the studs 70 (FIGS. 1 and 2), these are metallic studs extending vertically from runner 24 to runner 24, the thickness of the stud being sufficiently less than the width of the runners 24 to give a snug-toloose fit therein. The studs 70 are characterized, as best seen in cross-section, FIG. 2, as comprising a base 72 and

side flanges

74 and 76 extending from the base at the extreme edges 78 thereof. The base 72 is completely imperforate, and by means of the construction of the side flanges, covers the side flanges and the channel formed by them. That is, each of the side flanges is bent flat at edges 78 so as to fonn an angle of approximately 180, the flanges touching the base 72 at this point. Portions 80 are formed by bending the

flanges

74 and 76 approximately away from the base 72, so that the side flanges extend from under the base The length of portions 80 are approximately equal to the width of the liner members 30. The bends preferably are shaped so as to bias the portions 80 into contact with each other. This makes the joint between the flanges a minimum width joint covered by an imperforate base. The remaining portion of the

flanges

74 and 76 are then bent through angles of approximately 90 each. The first such bend extends the flanges away from each other and parallel to the base, forming pockets 82 for the members 30. The second bend extends the flanges to the partition members 50 where the ends are bent a third time so as to form flat end attaching portions 84 for the partition member 50 and screws 68. These flat attaching portions extend parallel to and beyond the width of the base 72, thus giving the stud a broader base for stability. From the point of the first bend in the flanges described above, each of the flanges is formed so as to not extend again toward itself or the other flange, whereby the interior of the stud formed by the flanges is completely accessible from the exterior of the stud. The screws 68 pass into the end portions 84 to anchor the partition members to the stud.

The pockets 82 thus provide for an engagement of the liner members 30 by the studs 70 at the three

sides

32, 34, and 36 or 38 of the liner members. The stepped configuration of the flanges from portions 80 to ends 84 provides the air gap 69, which is characteristic of the cavity wall. The gap accommodates utilities such as conduit 71. As shown in FIG. 2, the utilities may be located between the side flanges, or it may be outside them.

The overall effect is to form a complete fire barrier for fires in the shaft 12, and at the same time anchor the side flanges against possible collapse or spreading of the side flanges under conditions of severe pressure loading in the shaft 12. Further, the construction of the stud permits rapid manufacture and, specifically, the use of a flying shear. Such a shear does not work effectively if the stud has a closed volume, as such volume is not capable of mandrel support at the shearing stage. Instead, the stud 70 has been designed so that the

side flanges

74 and 76 are bent so as to lie immediately adjacent the base at their portions 80 with no space in between, and thereafter are bent so as to not close upon themselves or each other, whereby interior surfaces of the stud are accessible from a position exterior to the stud.

A stud different from the stud 70 must be used at the wall corners 90, and also at other peculiar wall features such as door jambs (not shown). This is stud 100 which is inserted within the runners to start a comer 90. This stud is identical with one of those described in the aforesaid copending U. S. patent application. Briefly it comprises a channel having a base 104 the width of which exceeds the thickness of the liner members 30 by an amount approximately equal to the width of the air gap 69.

Side flanges

106 and 108 extend generally perpendicularly from the base. Flange 106 is short, but flange 108 extends further and is bent to form a portion 112 which extends parallel to the base toward the flange 106 by a distance approximately equal to the thickness of the liner members 30. The general shape in cross-section is thus one of a G. Two such studs 100 are generally positioned base to side flange to form the corner 90.

FIG. 3 illustrates an alternate embodiment of the stud which adds, between the anchoring ends of the side flanges and the remainder of the flanges, means for reducing the amount of sounds transmission between the two

rows

30 and 50. Parts similar to those previously described bear the same reference numeral to which the distinguishing suffix a has been added. Thus, in FIG. 3 the stud 700 has the same base 72a and pockets 82a as before. The

flanges

74a and 76a extend away from each other beyond portions 80a, cut-off by a flying shear. However, the anchoring end positions 84a are joined to the remainder of

flanges

74a and 76a by means of resilient curves or bends which serve to absorb at least some of the sound which would otherwise be transmitted through the stud. Improved sound attenuation is thus achieved by the wall 16a. This improved sound attenuation makes the stud 70a conducive for use in still another wind-loaded cavity wall, namely a curtain wall. In such a case, the walls construction would be identical as in wall 16a, except that the members 30a would be pre-coated gypsum wallboard, steel, or marble panels. The gauge of the studs would be preferably 8 or 9, and sound and thermal insulating material would be inserted in the air gap 69a.

FIG. 4 illustrates another embodiment wherein the pockets are differently formed. Parts similar to those previously described have the same reference numeral to which the distinguishing suffix b is added. Thus, as shown in FIG. 4, the wall 16b is identical with previously described embodiments, except that the portions 80b of the

side flanges

74b and 76b of the stud 70b are in contact the full width of the stud. The remaining portions of the flanges then are bent away from each other and thence parallel to portions 80b. The free ends of the side flanges complete the three-sided engagement of the liner members 30b by the stud.

FIG. 5 illustrates yet another embodiment of the stud, which is shown in a curtain wall configuration. However, it will be readily apparent that any cavity wall can be constructed with this embodiment. Parts similar to those previously described bear the same reference numeral to which the distinguishing suffix c has been added. Thus, curtain wall 160 is formed by marble panels 300 which face the exterior of the building, the panels being held without fasteners by the pockets 82c in the studs 70c. As before, the imperforate base 720 is exposed to .the wind loading and the side flanges 74c and 760 penetrate into the wall and are attached at the end portions 840 to the interior members 50c of the wall. Unlike previous embodiments, however, the pockets 820 are formed by lancing and bending out tabs from the side flanges. Otherwise, as in the embodiment shown in FIG. 4, the side flanges contact each other the entire distance from the base 72c to the partition members 50c, which is the full width of the stud.

Therefore, it is readily apparent that more than one embodiment can be constructed and still make use of the invention. Thus, it is intended that the invention cover all arrangements, equivalents, and alternate embodiments as may be included within the scope of the following claims.

What is claimed is:

1. An air shaft cavity wall enclosing an air shaft in a building extending continuously through at least two stories and subjected to destructive wind loading, the wall comprising at least one floor and adjacent ceiling cutaway to define the continuous shaft therethrough, a plurality of studs and two rows of partition members spaced apart by the studs, the studs being characterized by an imperforate base, two side flanges, and means for engaging two of the members of one row on three vertical sides thereof, each of the bases and one row of the partition members being exposed to the shaft, and each of said flanges extending into the wall from under the base away from the shaft between the engaged members, said flanges each having at least a portion thereof in contact with the other side flange, said contacting portion being positioned immediately adjacent to the base with substantially no space therebetween, said flanges each extending from said contacting portions both parallel and generally perpendicular to the base and so as to not extend again toward the other flange, whereby the interior of the stud formed by the flanges is completely accessible from the exterior of the stud.

2. The wall as defined in claim 1, wherein said means include pockets formed by bends in said side flanges.

3. The wall as defined in claim 2, wherein said side flanges contact each other at portions thereof.

4. The wall as defined in claim 3, wherein said contacting portions are covered by said base so as to form a channel between the side flanges which is closed off by the base, whereby the joint between the two engaged partition members is a minimum width and is covered by an imperforate piece of metal.

5. The wall as defined in claim 4, and further including means on side flanges for anchoring each flange to the other row of partition members.

6. The wall as defined in claim 5, wherein said anchoring means include portions of each side flange bent so as to extend parallel to and beyond the width of the base, said portions terminating within the wall, whereby said anchoring means are spaced as far from the joint of the engaged members as possible.

7. The wall as defined in claim 6, wherein each of said parallel, bent portions are joined to the remainder of the said flange by a resilient bend adapted to minimize sound transmission from said one row to said other row.

8. The wall as defined in claim 5, and further including resilient means between said anchoring means and the remainder of the side flanges for reducing the amount of sound transmission between the two rows via the stud.

9. An air shaft cavity wall in a building extending continuously through at least two stories and subjected to destructive wind loading, the wall comprising at least one floor and adjacent ceiling cut away to define the continuous shaft therethrough, a plurality of studs and two rows of partition members spaced apart by the studs, the studs being characterized by an imperforate base and two side flanges extending from the base, said flanges each having at least a portion thereof in contact with the other side flange, said contacting portion being positioned immediately adjacent to the base with substantially no space therebetween, said flanges each extending from said contacting portions both parallel and generally perpendicular to the base and so as to not extend again toward the other flange, whereby the interior of the stud formed by the flanges is completely accessible from the ext erigr of thg Stlid.

Claims

1. An air shaft cavity wall enclosing an air shaft in a building extending continuously through at least two stories and subjected to destructive wind loading, the wall comprising at least one floor and adjacent ceiling cut away to define the continuous shaft therethrough, a plurality of studs and two rows of partition members spaced apart by the studs, the studs being characterized by an imperforate base, two side flanges, and means for engaging two of the members of one row on three vertical sides thereof, each of the bases and one row of the partition members being exposed to the shaft, and each of said flanges extending into the wall from under the base away from the shaft between the engaged members, said flanges each having at least a portion thereof in contact with the other side flange, said contacting portion being positioned immediately adjacent to the base with substantially no space therebetween, said flanges each extending from said contacting portions both parallel and generally perpendicular to the base and so as to not extend again toward the other flange, whereby the interior of the stud formed by the flanges is completely accessible from the exterior of the stud.

9. An air shaft cavity wall in a building extending continuously through at least two stories and subjected to destructive wind Loading, the wall comprising at least one floor and adjacent ceiling cut away to define the continuous shaft therethrough, a plurality of studs and two rows of partition members spaced apart by the studs, the studs being characterized by an imperforate base and two side flanges extending from the base, said flanges each having at least a portion thereof in contact with the other side flange, said contacting portion being positioned immediately adjacent to the base with substantially no space therebetween, said flanges each extending from said contacting portions both parallel and generally perpendicular to the base and so as to not extend again toward the other flange, whereby the interior of the stud formed by the flanges is completely accessible from the exterior of the stud.