Seismic wall system

Abstract

The wall system includes a ceiling runner, a floor runner and studs that are mounted between the ceiling runner and the floor runner. The ceiling runner is specially designed to allow for movement of the ceiling relative to the floor without damaging the wall. The ceiling runner design accommodates this movement with loose slots for the studs that allow for vertical movement and mounting slots that allow for vertical support but also allows for horizontal movement.

Description

This patent application claims priority to U.S. Provisional Patent Application No. 60/592,446 filed Jul. 30, 2004. The contents of to U.S. Provisional Patent Application No. 60/592,446 are hereby incorporated by reference.

BACKGROUND

The weight bearing walls, floors and ceilings of a large building are frequently constructed from steel reinforced concrete. Within each floor of these buildings, walls are installed to partition areas and form separate rooms in the building. The walls are formed from wallboards mounted on steel beam wall frames. The wallboards provide a solid and insulative wall surfaces but are not structural. The steel beam frames provide a strong surface to support the wallboards.

With reference to FIG. 1, the steel beam wall frame 105 is made of a plurality of steel beam components, including: a floor runner 109, studs 111 and a ceiling runner 115. A ceiling runner 115 is a horizontal beam that defines the top edge of the wall and a floor runner 109 is a horizontal beam that defines the bottom edge of the wall. The studs are vertical pieces which are placed between the ceiling runner and floor runner. The studs are evenly spaced parallel to each other and perpendicular to the ceiling and floor runners. At the corners of the room, the ceiling and floor runners may be cut at 45 degree angles and the adjacent ceiling and floor runners are connected to form the 90 degree corners. The cross-section of these steel beams is designed to be structurally rigid while minimizing weight. The C-channel is a common cross section of a steel beam.

Conventional building practices include the initial laying out of markings on the floor showing wall locations in accordance with the floor plan. Thereafter, starting with an outer wall, a ceiling runner in the form of an inverted C-channel is secured to the concrete ceiling around the perimeter of the new wall. The next conventional step is to secure the floor runners, which are upwardly facing C-channels, to the floor along the perimeter walls. Thereafter, the spacing of the studs is determined. This involves laying out such spacing by applying markings to the channels of both of the upper and lower runners. The next step is to measure the distances between the lower runner and the ceiling runner in order to determine the length of the studs. The studs are then cut according to such measured lengths.

The cut studs are then stood in place free-stand within the ceiling and floor runners. The studs are secured to the ceiling runner at their upper ends and the floor runner at their lower ends. Screws or welds may be used to secure the studs to the ceiling and floor runners. Once the steel frame is constructed, the wallboard is attached to the studs with screws or other fasteners. The wallboards is then typically covered with plaster, textured and painted to conceal the screw holes.

Modem buildings are designed to resist damage during seismic activity by swaying with the movement rather than attempting to remain rigid. A problem with steel wall frames used in buildings placed in areas of high seismic activity is that as the building flexes, there is relative movement between the floors and ceilings of the buildings. Because traditional walls are secured to both the floor and ceiling, the wallboards tend to be damaged as the studs deflect with the movement. This bending of the studs frequently causes damage to the wallboard and fasteners. After the seismic activity is complete, the damaged walls must be repaired.

What is needed is a system that prevents steel wall frames from being damaged during an earthquake.

SUMMARY OF THE INVENTION

The inventive ceiling runner and wall system prevents damage within a building by providing a wall frame that is flexible both vertically and horizontally. The wall system has the basic configuration of vertical studs mounted between floor runners that are secured to the floors of the building and ceiling runners that are attached to the ceilings. The ceiling runner has channels that hold the tops of the studs in place but also allow the stud to slide vertically within the ceiling runner. There are no fasteners or other components that rigidly secure the stud to the inventive ceiling runner.

The ceiling runner also has mounting slots that are used to secure the ceiling runner to the ceiling but also allow the ceiling runner to move horizontally. Fasteners are placed in the slots of the ceiling runner and secure the ceiling runners vertically to the ceiling. The bodies of the fasteners fit loosely within the slot but the heads of the mounting bolts are wider than the slots so the fastener heads hold the ceiling runners to the ceiling. The fasteners are adjusted to minimize the friction between the ceiling runner and the fastener and ceiling surface. The loose fasteners allow the inventive ceiling runner to slide horizontally along the path of the mounting slots.

When a building that has the inventive interior wall system moves, the ceiling can move vertically and/or horizontally relative to the floor. If the distance between the floor and ceiling expands, the studs slide partially out of the ceiling runner channels. Conversely, if the distance between the floor and ceiling contracts, the studs slide further into the ceiling runner channels. If the movement of the building causes horizontal shearing between the floor and ceiling, the mounting slots allow the wall to move horizontally relative to the ceiling without damaging the wall. If the movement is perpendicular to the slots, the wall will rotate about the floor runner however the wall can rotate in this manner without sustaining any damage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing of a prior art stud and runner wall system;

FIG. 2a is a cross section view of the seismic wall system;

FIG. 2b is a side view of the seismic wall system;

FIGS. 3a is a cross section view of the ceiling runner;

FIG. 3b is a side view of the inventive ceiling runner;

FIG. 3c is a perspective view of the inventive ceiling runner;

FIG. 3d is a bottom view of the inventive ceiling runner; and

FIG. 4 is a view of the fasteners and spacers used with the ceiling runner.

DETAILED DESCRIPTION

The inventive ceiling runner prevents seismic damage to interior walls of a building with a system that securely supports the wallboard but is not rigidly fasten the wall to the ceiling. The wall using the inventive ceiling runner may initially assembled by attaching the studs to the floor and ceiling runners as shown in FIG. 1.

Interior walls for a building are first laid out in a plan before installing the walls. Measures are taken to determine the dimensions of the existing space as well as the lengths of the new walls. The dimensions are plotted to create a top view of the walls for the project. The spacing of the studs within the walls are determined by the wall height and the stud size. The walls are strengthened by with more studs and larger studs. Shorter walls do not require as much strength and can use smaller studs that are spaced farther apart. Higher walls require closer stud spacing and possibly larger studs. The standard spacing between studs is either 12″, 16″ or 24″ on the centers of the studs. See table 1 below.

	TABLE 1
	Stud Spacing
	12″	16″	24″
	Stud Size (in.)	Allowable Wall Height (ft.-in.)
	1-⅝	7-10	7-1	6-2
	2-½	10-10	9-10	8-6
	3-⅝	14-4	13-0	11-5

After the walls have been designed, they are constructed. The studs and runners are cut to the required lengths. This cutting can be performed with aviator snips or circular saw with abrasive metal-cutting blade. The ceiling runner is attached to the ceiling. Drywall screws are used to attach the ceiling runner to joists. For parallel joists, C-runners spaced 24″ or less are used to bridge two joists. The ceiling runner is then installed across the bridges. The inventive ceiling runner has slots that the body of the fasteners are placed through. The heads of the fasteners are wider than the slots so the ceiling runners are supported by the fastener heads. The fasteners can slide within the slots allowing the entire ceiling runner to move horizontally relative to the ceiling. The runner slot and horizontal sliding movement will be described in more detail below.

A floor runner is installed directly below each ceiling runner. The floor runner may be more difficult to install if the building has concrete floors because powder-actuated fasteners may be required. If the building has wood subfloors, drywall screws can be used to fasten the floor runner. The studs are then inserted into the floor and ceiling runners. The stud can be attached to the floor runner with 7/16″ pan or wafer-head screws. The drywall is then attached to the studs typically with screw fasteners.

In the described method, the wall studs are installed after the runners have been attached to the floor and ceiling. In alternative embodiments, the studs and runners can be assembled before the wall is positioned within the building. In this alternative method, the wall assembly of runners and studs may be assembled like a normal wall frame but without any fasteners attached between the stud and the ceiling runner. The assembled wall is then moved into position in the building. The floor runners are attached to the floor of the building and the ceiling runners are attached to the ceiling. The wallboard is attached to the studs but not the ceiling runner. Because the tops of the studs are not fastened to the ceiling runner, a manufacturing step eliminating and construction speed is increased.

The inventive ceiling runner is a substantial improvement over the prior art because it is less prone to damage when the building moves as a result of an external force such as an earthquake. A rigid wall can easily be damaged by relative movement between the ceiling and floor. With a rigid wall assembly, if there is horizontal movement, the studs are forced out of vertical alignment causing damage to the wallboard. Similarly, if there is vertical movement, the fasteners holding the studs to the floor and ceiling runners can be damaged and the wall is exposed to compression or tension.

The inventive ceiling runner overcomes these problems by allowing the ceiling to move both vertically and horizontally without any damage to the wall. With reference to FIGS. 2a and 2b, the studs 205 are placed in slots in the ceiling runner 215 and are not rigidly connected with a fastener or a weld. The ceiling runner 215 is loosely attached to the ceiling 231 with fasteners 241 and the floor runner 209 is attached the floor 233 with fasteners 243. If there is vertical movement, the stud 205 slides within the ceiling runner 215. This eliminates any vertical forces that are applied to the floor 207 or ceiling 209 from being transmitted to the studs 205.

The fasteners 241 hold the ceiling runner 215 in place vertically, but allow the ceiling runner 215 some horizontal movement. If the ceiling 231 moves horizontally in line with ceiling runner 215, the ceiling runner 215 and wall assembly remain stationary relative to the floor 233. The horizontal ceiling 231 movement causes the fasteners 241 to slide within the slots in the web of the ceiling runner 215. This horizontal sliding capability also allows the studs 205 to remain in a straight vertical orientation perpendicular to the ceiling runner 215 and the floor runner 209. The vertical studs 205 keep the wall square so the wall board attached to the studs 205 will not be damaged, i.e. the wall remains rectangular rather than being forced into a slanted parallelogram.

A more detailed illustration of the inventive ceiling runner is shown in FIGS. 3a-3d. The inventive ceiling runner 301 has a modified C-channel cross section 303. The C-channel cross section 303 has a “web” 311 which is a horizontal section, two “flanges” 315 which extend vertically down from the web, and two “returns” 319 which extend inward from the flanges 315. The returns 319 are notched so that portions of the C-channel do not have returns. These notched sections 321 of the C-channel are designed to accommodate the ends of the studs (not shown) which fit between the flanges 315 of the ceiling runner 301. The notched sections 321 allow the steel studs to move up and down within the ceiling runner 301. In the installed configuration there are no screws, weld attachments or fasteners holding the stud within the ceiling runner 301. The notched sections 321 do prevent any significant horizontal or axial rotation movement of the studs. Although the returns 319 are shown as very short sections, it is also possible for these to extend partially or entirely across the width of the ceiling runner 301. This “floating” interconnection allows the wall frame to be flexible during an earthquake.

In another embodiment, the inventive ceiling runner has only a single return connected to only one of the flanges. This single return would still prevent horizontal movement of the top of the stud after it has been inserted into the inventive ceiling runner. However this single return design would not be as strong as the double return embodiment. Although the returns are illustrated as being at the upper edge of the flange, it is possible to form the returns from a different portion of the flange. A ceiling runner can be formed from a C-channel which originally only has a web and two flanges. The flange can be cut and bent inward to form the returns. Thus, the notches are created at the normal sections of the C-channel and the returns are formed at the sections where the flange is bent inward. Although the returns are illustrated as being bent at about 90 degrees inward from the flange, the return can be bent at any other inward angle as long as the edge of the return can engage the end of a stud and prevent horizontal movement.

In order for the ceiling runner to be able to slide, it is important to not have the fasteners tightly secured. Normally, construction workers use power screwdrivers or power wrenches to efficiently install all fasteners. The power tools are problematic because they inherently screw in all fasteners very tightly. To properly install the inventive runner, the fastener must be unscrewed to minimize the horizontal friction between the fastener and the ceiling runner.

In an embodiment, the over tightening of the fasteners to the ceiling runner can be accomplished by using a spacer. With reference to FIG. 4, the spacer 461 is slightly longer than the thickness of the web 411 of the ceiling runner 415 and fits within the slot 425 in the web 411. In this embodiment, the spacer 461 is placed around the fastener 441 to prevent the fastener 441 from tightly contacting the web 411. The spacer 461 may be made of a plastic that allows the ceiling runner to slide with less friction than metal In another embodiment, the fastener 442 may have an integrated spacer 465. This would eliminate the need to place the spacer 461 around each fastener 441 improving the efficiency of the installation. In yet embodiment, the spacer 467 may also include a flange 469 that would rest between the head of the fastener 441 and the web 411 of the ceiling runner 415. Similarly, a washer can be used in combination with the spacer 465. This flange 469 or washer is intended to further reduce the friction between the ceiling runner and the fasteners. By using a spacer with the fasteners, a worker can use the power tools to attach the fastener to the ceiling without having to loosen the fasteners to allow the ceiling runner to move horizontally.

The ceiling runner described may be fabricated from steel sheet metal which is bent into the specified C-channel cross section. Alternatively, the C-channel may be made using an extrusion process which uses a die. Once the C-channel is formed, the notches may be cut into the returns. In alternative embodiments, materials other than steel may be used to make the inventive ceiling runners.

The installation process for interior walls is simplified with the inventive ceiling runner. The ceiling and floor runners are installed first like the existing method, however, the studs are now inserted into the desired notched sections and then fastened to the floor runner only. Because the inventive ceiling runner holds the studs horizontally, there is no need to fasten the studs to the ceiling runner. The wallboards are then attached to the studs in the normal manner described above. Installation is simplified because the studs are not fastened to the ceiling runner and the fasteners are not removed after the wallboard installation.

Normally, the studs are placed at uniform intervals across the width of the wall. This interval may be 8, 16 or 24 inches. By forming notches at 8 inch intervals, the spacing of the studs can be any of these normal standards. Alternatively, the notches may be formed at 4 inch or 12 inch intervals. The 4 inch notch configuration allows the stud intervals to be 4, 8, 12, 16, 18 or 24 inches. The 12 inch notch confirmation allows the stud intervals to be 12 or 24 inches. Ceiling runners which have any other notch length interval can easily be fabricated. The slot in the web of the beam is used as bolt holes to attach the ceiling runner to the building's ceiling. The body of the bolt is screwed into the ceiling while the head of the bolt is wider than the slot and holds the ceiling runner to the ceiling.

The inventive ceiling runner comes in various sizes depending upon the building requirements. These dimensions and the physical characteristics of each size are listed in table 1. In the first column, the “depth” refers to the width of the ceiling runner. The numbers in the column are in inches, 250=2½ inches, 362=3⅝ inches, 400=4 inches, etc. The second column is the thickness of the sheet metal used to make the ceiling runner. The area is the cross sectional area of the ceiling runner. The weight is in pounds per foot length of the ceiling runner. The Section Modulus (Sx), Moment of Inertia for Deflection (Ixx), Effective Section Modulus (Sy) and Moment of Inertia (Iyy) are engineering characteristics for the ceiling beam which are not significantly altered by the inventive notch design.

Although the invention has been described with respect to the ceiling runner, it is also possible to use the inventive runner as a floor runner. By using a floor runner that has mounting slots in the web, the floor runner can also move horizontally. This may further reduce the damage to walls in an earthquake.

Although the description above contains many specifications, these should not be construed as limiting the scope of the invention but merely providing illustrations of some of the presently preferred embodiment of this invention.

Claims

1. A ceiling runner comprising:

a elongated web having a plurality of elongated mounting slots;

a first flange connected to a first edge of the elongated web;

a second flange connected to a second edge of the elongated web opposite the first edge; and

a first return connected to a side of one of the first flange opposite the elongated web;

wherein the web is substantially perpendicular to the first flange and the second flange and the first return creates a plurality of notches for holding a portion of a stud.

2. The ceiling runner of claim 1 further comprising:

a second return connected to a side of one of the second flange opposite the elongated web;

wherein the first return is angled away from the first flange towards the second flange and the second return is angled away from the second flange towards the first flange.

3. The ceiling runner of claim 1 wherein the plurality of slots in the web are equally spaced along the length of the web.

4. The ceiling runner of claim 1 wherein the plurality of slots in the web are substantially centered about the width of the web.

5. The ceiling runner of claim 1 wherein the plurality of slots in the web are approximately 0.15 to 0.5 inch in width.

6. The ceiling runner of claim 1 wherein the plurality of slots in the web are approximately 2 to 6 inches in length.

7. The ceiling runner of claim 1 wherein a first slot in the web is separated from a second slot in the web by approximately 2 to 6 inches.

8. The ceiling runner of claim 1 wherein the plurality of slots in the web are offset from the plurality of notches in the web along the length of the ceiling runner.

9. The ceiling runner of claim 8 wherein the plurality of notches in the return are approximately 1.75, 2.625 or 3.75 inches in length.

10. The ceiling runner of claim 8 wherein the plurality of notches in the return are separated from each other by approximately 4 to 7 inches.

11. A frame for a wall comprising:

a plurality of studs;

a floor runner that is fastened to a floor and has a plurality of slots that are fastened to a lower portion of the studs;

a ceiling runner comprising: a elongated web having a plurality of elongated mounting slots; a first flange connected to a first edge of the elongated web; a second flange connected to a second edge of the elongated web opposite the first edge; and a first return connected to a side of one of the first flange opposite the elongated web and having a plurality of notches;

wherein the web is substantially perpendicular to the first flange and the second flange and wherein the plurality of notches are sized to hold a top portion of the studs.

12. The frame for a wall of claim 11, wherein the ceiling runner further comprises:

a second return connected to a side of one of the second flange opposite the elongated web;

wherein the first return is angled away from the first flange towards the second flange and the second return is angled away from the second flange towards the first flange.

13. The ceiling runner of claim 11 wherein the plurality of slots in the web of the ceiling runner are equally spaced along the length of the web.

14. The ceiling runner of claim 11 wherein the plurality of slots in the web of the ceiling runner are substantially centered about the width of the web.

15. The ceiling runner of claim 11 wherein the plurality of slots in the web of the ceiling runner are approximately 0.15 to 0.5 inch in width.

16. The ceiling runner of claim 11 wherein the plurality of slots in the web of the ceiling runner are approximately 2 to 6 inches in length.

17. The ceiling runner of claim 11 wherein a first slot in the web of the ceiling runner is separated from a second slot in the web by approximately 2 to 6 inches.

18. The ceiling runner of claim 11 wherein the plurality of slots in the web of the ceiling runner are offset from the plurality of notches in the web.

19. The ceiling runner of claim 18 wherein the plurality of notches in the return of the ceiling runner are approximately 1.75, 2.625 or 3.75 inches in length.

20. The ceiling runner of claim 18 wherein the plurality of notches in the return of the ceiling runner are separated from each other by approximately 4 to 7 inches.