SNAP-SCREW STEEL FRAME AND CONCRETE BUILDING SYSTEM
I. Field of the Invention
This invention relates to frames for buildings and buildings constructed from such frames, and more particularly to high quality buildings that can be erected quickly and at low cost from studs and rails preferably made of steel.
II. Background of the Invention
Conventional building practice for residence housing relies primarily on wood frame construction in which the building frame is constructed on site from framing lumber cut to fit piece-by-piece individually. It is a labor intensive process and demands considerable skill from the carpenters to produce a structure that has level floors, perfectly upright walls, square corners and parallel door and window openings. Even when the building frame is constructed with the requisite care and skill, it can become skewed by warping of the lumber, especially modern low grade lumber produced on tree farms with hybrid fast-growth trees. Although conventional wood frame buildings require very little equipment for construction, they have become quite costly to build. The labor component of the cost is substantial, partly because of the straight wages that must be paid for the long laborious process of constructing the frame, and partly because of the many government mandated extra costs such as workman's compensation and liability insurance, social security payments, medical insurance premiums, and the host of reports that must be made to the government by employers. Accordingly, employers now seek to minimize their work force by whatever means is available to minimize these burdensome costs.
Steel frame construction is commonly used on commercial buildings because of its greater strength, fire resistance and architectural design flexibility. The parts of such a steel frame are typically built to order in accordance with the architect's plans, then trucked to the building site and assembled piece-by-piece with the use of a portable crane. The building can be made precisely and as strong as needed, but the cost is relatively high because of the skilled crew and expensive equipment need to assemble the building. It is a construction technique generally considered unsuitable for single family residence building because the cost is high and the building walls are substantially thicker than those made using standard frame construction, so standard door and window units do not fit
properly and must be modified with special trim that rarely produces an aesthetic appearance.
Earthquake damage is becoming a matter of increasing concern among homeowners because of the publicity given to damage and loss of life in recent earthquakes around the world. Earthquake preparedness stories and advice abound, but an underlying unresolved concern is that conventional wood frame homes in the past were not built to tolerate the effects of an earthquake, neither in its ultimate load-bearing capability nor its serviceability limits. Modern building codes attempt to address this concern, but the measures they require merely add to the already high cost of a new home and may not always provide significantly improved resistance to earthquake damage, particularly with respect to after- quake serviceability.
Fire often follows an earthquake, as happened in the disastrous Kobe earthquake of 1994, and of course fire is a major threat to homes independent of earthquake. When fire breaks out in a conventional home, the wood frame fuels the fire and reduces the chances of successfully extinguishing it before the entire structure is destroyed. The major life saving advance in the recent past is the fire alarm which detects the fire and merely alerts the occupants that a fire has started so they may escape before burning up with the house, but significant improvements to the fire resistance of the home itself that would retard the spread of the fire would be desirable.
The other major catastrophic threat to homes is wind. Wind loads on wood frame homes have destroyed many homes, primarily because the roof is usually- attached so weakly to the walls that the combination of lift, exerted upward on the roof by the Bernoulli effect of the wind flowing over the roof, and pressure under the eves tending to lift the roof off the walls, wrenches the roof off the walls and allows the wind to carry the roof away like a big umbrella.
Termite and carpenter ant damage to wood frame homes is a major form of damage, costing many millions of dollars per year. Although the damage done by insects is rarely life threatening, it is actually more extensive in total than the combined effects of wind and earthquake, and it is an ever present danger in many parts of the world.
Thus, there exists an increasing need for a home building frame design that would enable the inexpensive construction of homes that are highly tolerant
of the effects of earthquakes, do not support combustion, are capable of withstanding high winds, are immune to damage from insects, and can use standard building components such as door and window units. Such a building frame concept would be even more commercially valuable if it were possible to erect the building in a short time with a small crew and without heavy equipment, and the frame could be adapted to produce buildings of attractive building styles desired locally. III. Summary of the Invention
This invention provides a building system for constructing homes inexpensively while protecting the structure against the forces of nature.
An objective of the invention is to provide a snap-screw steel frame and concrete housing system preferably with steel reinforced concrete columns at the corners and between peripheral wall intersections.
Another objective of the invention is the flexibility of design allowed by the building material and method of construction.
Another objective of the invention is the speed at which a house or building may be constructed.
Another objective of the invention is to provide a structure capable of withstanding high winds resulting from, for example, hurricanes, monsoons, and tornados.
Another objective of the invention is the flexibility of assembly of wall panels off-site to further speed the construction of a structure or assembly of the entire structure on-site.
A further objective of the invention is to provide a structure built with a steel frame thus reducing the cost of construction over traditional methods.
A further object of this invention is to provide a frame for a house that can be built to withstand severe earthquakes and high winds yet is inexpensive as compared to wood frame houses.
A still further object of this invention is to provide an improved process for constructing a frame for a house that is less costly than conventional wood frame houses and substantially more resistant to damage from earthquakes and wind.
Yet another object of this invention is to provide a steel frame home having walls the same thickness as a conventional wood frame home so that standard door and window units can be used while providing a normal appearance and also
having a home that has the strength and fire resistant benefits of a steel frame building and costing less than conventional wood frame buildings.
An advantage of the invention is that a variety of roofing material may be used including galvanized steel sheets, tile, or shingles, for example. Another advantage of the invention is that the footings are preferably positioned at intersections of the wall panels to complete a vertical tensile load path from the roof to the foundation for holding the roof down in high winds, and to secure the building frame to the foundation against lateral forces exerted by wind loads or earthquakes. Another advantage of the invention is that preformed steel studs are provided thus avoiding the need to cut rectangular steel or wood to a correct size for use on-site.
Another advantage of the invention is the inexpensive materials used in construction, the decrease in labor costs to construct the building, and other cost savings that will become apparent based on this description.
Another advantage of the invention is the flexibility offered in the design of a home at a minimum that is equivalent to the flexibility offered by wood.
Given the following enabling description of the drawings, the apparatus should become evident to a person of ordinary skill in the art. IV. Brief Description of the Drawings
The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements.
Figure 1 illustrates an exemplary assembled frame built according to the invention.
Figure 2 depicts an exploded view of the frame illustrated in Figure 1. Figure 3 illustrates a cross-section of a footing and column structure of the invention.
Figure 4(a) depicts an embodiment of the floor panels of the invention. Figure 4(b) depicts a cross-section of the floor of the invention.
Figure 5 illustrates an exploded view of a column in accordance with the invention.
Figure 6 illustrates an exploded view of wall structure in accordance with the invention.
Figures 7-20 depict different exemplary wall panels in accordance with the invention.
Figures 21(a)-(b) illustrate an embodiment for a roof structure in accordance with the invention. Figures 22(a)-(b) depict an alternative embodiment for a roof structure in accordance with the invention.
Figures 23(a)-(b) illustrate external views of an exemplary house built according to the invention.
V. Best Modes for Carrying Out the Described Embodiments Figures 1-20 illustrate an exemplary embodiment of the invention. Figures
1 and 2 more particularly show a frame for a home and an exploded view of that frame, respectively. Figures 7-20 illustrate the different wall sections used to assemble the frame illustrated in Figures 1 and 2.
The basic building components for the frame for this invention preferably are a "C" cross-section stud (hereinafter C stud), a "U" cross-section rail (hereinafter U rail), trapezoidal galvanized sheets, and/or flat sheets. The U rail preferably includes a main wall with two extending members that preferably are perpendicular to the main wall to form a U-shaped channel. The C stud preferably is a U rail with the addition of a flange extending from each of the two extending members to form a channel with a "C" cross-section.
Preferably, these components are manufactured from flat steel stock, which may be delivered coiled to a fabrication site. More preferably, the steel ranges in thickness from 25g to 18g with a width of 7 inches to 17 inches to allow for the formation and creation of different widths of C studs and U rails. Depending upon availability of coiled steel and other factors, the invention may be practiced using just C studs, just U rails, or some combination of the two. Most preferably, C studs are used throughout the building frame. Although wood studs may be used for the roof trusses.
One way to manufacture the C studs, U rails, and flat pieces is as follows. The coiled steel is placed on a power decoiler that feeds a leveler (or straightener) that flattens the steel for manufacture of the components. The leveler removes coil-set, which is the bend that is induced into the steel during the coiling/unwinding process. The straightened steel then passes into a pneumatic feed control system and then on to a hydraulic unit. The feed control system is a
drive/measuring unit that indexes the steel so that the hydraulic unit is able to punch a hole as needed, create notch pairs as needed, and shear/cut the steel to appropriate lengths. The distance between punches/cuts in the steel is calculated based on instructions from a programmed controller to allow at least semi- automatic operation and manufacture of the steel components. Once the steel is punched at predetermined locations, punched to form notch pairs, and cut to the correct length, the steel (or blank as it is now known) passes onto an electrical transfer table to be lined up to pass through the rolling/forming mill, which is set up to produce the appropriate cross-sectional configuration for each piece. After being formed the piece exits the mill onto a run off table and is removed by a worker.
The invention is preferably built using footings 100 as illustrated in Figure 1 to in part protect against high water, for example, from a flood or high tide. Preferably, the footings 100 include a base 110 and a pillar 130. The base 100 preferably is poured concrete, and more preferably the poured concrete includes at least one reinforced steel bar 112 within the base 110 to further strengthen it. The pillar 130 preferably is a column of reinforced concrete blocks 132, such as eight-inch block, that once stacked are filled with concrete. Preferably, a reinforcing bar(s) 134 runs from the base 110 up through the pillar 130 and out the top of the pillar 130. The reinforcing bar 134 may have a horizontal portion 1342 in the base 110 in addition to the vertical portion 1344 running up through the pillar 130.
The footings 100 preferably provide the surface upon which the flooring substrate 200 is placed. Preferably, the flooring substrate 200 is constructed out of groupings of C studs assembled into floor panels 210 as illustrated in Figure 4(a). Each floor panel 210 preferably includes two C studs as header joists 212 running the length of the floor panel 210. Each of these header joists 212 preferably will have notch pairs 214 spaced along its length. The header joists 212 preferably will be aligned with each other such that the respective ends and notch pairs of one header joist 212 lines up with the other header joist 212.
Each notch pair 214 preferably will receive a C stud crossing beam (or joist) 216. Preferably, each crossing beam 216 will be perpendicular to the header joist 212. The juncture of the header joist 212 and a crossing beam 216 preferably will be secured using self-tapping screws 150 (such as 5/8"), a weld,
bolts, or other similar securing means. The crossing beams 216 preferably will face the same way except for an end cap C stud 218, which will face the opposite direction as illustrated in Figure 4(a). The use of "floor beam 216" in this application will represent the header joist 212, crossing beam 216, and end cap 218 depending upon the location of the attachment and orientation of a particular floor panel.
Each floor panel 210 preferably provides a modular aspect to the size of the floor plan that may be created with this invention. Preferably, each floor panel 210 will then be attached and/or connected to neighboring floor panels 210. Each floor panel 210 then preferably will be covered with a trapezoidal galvanized sheet 230 as illustrated in Figures 4(a)-(b) to keep cost down as compared to the alternative of plywood, which may be used instead. Depending upon the size of the floor panel 210 multiple trapezoidal sheets 230 may be required, alternatively the trapezoidal sheets 230 may overlap onto multiple floor panels 210. Preferably, the trapezoidal sheet 230 will be held in place with self- tapping screws 150, a weld, or other similar securing item as spaced intervals across its surface. The flooring substrate 200 preferably is completed by providing a layer of cement 220, which preferably allows for at least 3000 pounds per square inch of pressure and/or is approximately four inches thick measured from the floor beam 216, more preferably the concrete 220 is reinforced with a mesh 222.
Each floor panel 210 preferably will be attached to the footings 100 below it with a strap 140, which preferably is a galvanized strap (or other type of hurricane tie down) that more preferably is one inch wide. The strap 140 preferably is inserted into the poured concrete prior to it setting within the pillar of concrete block 130 and extends out the top such that it may be looped preferably around the main wall of a floor beam 216 as illustrated in Figure 3.
Spaced along the peripheral floor beams 216 are columns 250 as illustrated in Figures 1 and 2, more preferably a column 250 will be above a peripheral footing. Preferably, a column 250 separates wall panels 300 around the periphery of the building. A column 250 also preferably is at all corners of the periphery of the building. Figure 5 illustrates an exploded view of the preferred embodiment of the column 250 above a floor beam 216. Preferably, the column
250 is formed by two facing C studs (or U rails) 252, 252 and two flat stock steel pieces 254, 256.
The flat stock steel pieces 254, 256 are preferably of different lengths such that the outside piece 254 extends above and below the studs 252, 252 and the inside piece 256 extends from the top of the studs 252, 252 down to a point along the studs 252, 252. The extra length at the bottom of the outside piece 254 overlaps with the main wall of the floor beam 216 (not illustrated in Figure 3) and as such preferably is attached using self-tapping screws 150 and/or a weld (not shown). More preferably, the overlap of the outside piece 254 is adjacent the strap 140 and further holds the strap 140 against the floor beam 216. Preferably, the overlap is such that the outside piece 254 extends to the bottom of the main wall of the floor beam 216. The extra length at the top of the outside piece 254 preferably is for attachment to the roof structure.
Preferably, the flat stock pieces 254, 256 are held to the studs 252, 252 using either self-tapping screws 150 or welds preferably spaced at intervals along the height of the column 250, more preferably the self-tapping screws 150 are spaced at six inch intervals in horizontal pairs (one screw for each stud 252, 252 in the column 250). Once the column 250 is installed above the floor beam 216, preferably the column 250 is filled with concrete 258. Additionally, it is preferable that the reinforcing bar 134 running up from the base 110 extends up through the floor beam 216 into the column 250. More preferably, at least one second reinforcing bar 136 extends from a top area of the concrete block pillar 130 through the floor beam 216 into the column 250. Most preferably, there are two second reinforcing bars 136 running through each column 250. The wall panels 300(a-n) as illustrated, respectively, in Figures 7-20 are designed such that they can be assembled off-site, in which case preferably they will have the various connections welded together, or on-site, in which case preferably there will be self-tapping screws 150 used at the connection points/joints. Figures 7-20 illustrate a variety of exemplary wall panel configurations that are also illustrated in Figures 1-2. Preferably, C studs are used throughout the wall panels such that the closed side of border studs (or border members) 320 for a wall panel abuts other building features like door frames, window frames, other wall modules, columns, floor beams, or the roof structure. The studs used in the wall panels preferably will have notches along
their respective lengths where other studs will intersect with them such that the notches nest the other intersecting studs. An example of this is Figure 6, which is a partial exploded view of the wall panel 3001, which also is illustrated in Figure 18, and shows the use of self-tapping screws 150 to secure the connections. Figure 6 shows the wall panel floor (or floor member) 310 as having a series of notch pairs 312 to insert the border studs 320, vertical members 322, 324, and support member 326 that attach to the floor. The wall panel floor 310 preferably is attached to the floor beam 216 using self-tapping screws 150 spaced along its length, more preferably the self-tapping screws 150 are spaced at six inch intervals. Likewise, preferably the border studs 320 will abut the neighboring panel, column 250, window unit, door unit, or space (e.g., if it is an open walkway) with its main wall. When the border studs 320 abut a neighboring panel or column 250, preferably a series of self-tapping screws 150 are spaced along the length of the end panel stud 320 to form a connection between the neighboring pieces, more preferably the spacing for the self-tapping screws is six inches. The wall panel top (or ceiling member) 314, like the wall panel floor 310, preferably includes a series of notch pairs 312 that accept vertical studs. Alternatively, the wall panels 300 may also include vertical members 328 that run from the wall panel floor 310 up to the wall panel top 314 and have no other joints. Preferably when a longer stud (like 322 or 324) that forms part of and continues through a joint 350 with another stud (like 342 or 344), the longer stud 322, 324 will have a pair of notches 312 formed to accept the other stud as illustrated in Figure 6. More particularly, vertical members 322, 322 each preferably include a notch pair 312 for accepting a horizontal member 342. These three members and the wall panel floor 310 preferably form a frame for insertion of a door unit. To provide additional support to this frame, it is preferable to add a vertical support member 326' that will preferably fit into a notch pair 312 of the horizontal member 342 and a notch pair 312 of the wall panel top 314.
Also illustrated in Figure 6 is a preferred window frame for insertion of a window unit. Vertical members 324, 324 each preferably include two notch pairs for accepting a first and second horizontal members 342', 344. Preferably, the first and second horizontal members 342', 344 include a notch pair 312 aligned with a notch pair 312 in the wall panel top 314 and the wall panel floor 310, respectively. A vertical support member 326 is preferably inserted between the
second horizontal member 344 and the wall panel floor 310 and thus into the respective notch pairs to provide additional support. A vertical support member 326' likewise preferably is inserted between the first horizontal member 342' and the wall panel top 314 and thus into the respective notch pairs to provide additional support.
As shown in Figures 6-20, preferably all of the vertical studs will have at least one hole 360 lined up with other holes in other vertical studs such that electrical wiring, telephone wiring, or other utility conduit and/or wiring may pass through the studs and remain on the inside of the panel. These wall panels 300 can for example be covered with standard siding, T & G finish, or other material on the outside of the structure 510 and wall board on the interior walls.
As illustrated in Figures 7-20, the studs used in this invention can be arranged in a variety of patterns and arrangements. The wall panels 300g, 300h illustrated in Figures 13 and 14, respectively, are used to provide a structure for a top border for the porch 500 illustrated in Figures 1 and 23(a). The wall panel 300j illustrated in Figure 16 is used for an interior walkway. The wall panels 300e, 300i, 300I, 300m, 300n illustrated in Figures 11 , 15, 18, 19, and 20, respectively, include a space for the insertion of a standard door unit preferably using the stud structure as discussed above. The wall panels 300a, 300b, 300c, 300d, 300e, 300f, 300I illustrated in Figures 7-12 and 18, respectively, include a space for the insertion of a window unit preferably using the stud structure as discussed above. Figures 21 (a)-(b) illustrate the roof structure that may be made out of C studs, U rails, or wood. Preferably, the roof structure edge is flush with the peripheral wall of the structure. Figures 21 (a)-(b) more particularly illustrate an exemplary embodiment using wood. Figure 21(b) illustrates the interior roof support system that preferably includes 2" x 4" collar beams 410, 2" x 4" wallplates (or top plates) 412, and 2" x 4" studs (or king or queen posts) 414. The studs 414 preferably are spaced at intervals along the wallplates 412, more preferably they are spaced at twenty-four inch intervals. Figure 21 (a) shows the interior support system encompassed within an outer roof structure. The outer roof structure preferably includes a foundation of 2" x 4" wallplate 422 supporting 2" x 8" hip rafters 424 in the corners and 2" x 6" rafters 426 perpendicular to the wallplate 422. Most preferably the rafters 426 are spaced at twenty-four inch intervals. The hip rafters
424 and rafters 426, not intersecting hip rafters 424, preferably run from the wallplate 422 to a 2" x 8" ridge board 428 that preferably rests on top of a wallplate of the interior support system.
Alternatively, the roof could be constructed using C studs in place of the wood described in the previous paragraph or as follows. Preferably, a C stud of the same structure as the floor beams runs along the length of the house structure on each side. These roof C studs also preferably include a series of notch pairs for C stud rafters that ascend up to a central ridge C stud. Preferably, there is a C stud beam with its main wall abutting the top of the wall panels running down the center of the house. This central C stud beam preferably includes a series of notch pairs that are spaced, preferably at the same intervals as the side C studs, to nest king post C studs running up to the central ridge C stud, which has a notch pair for each king post.
Another alternative roof structure is to use roof panels 210b, which preferably are similar to the floor panels 210 where the end beam and crossing beams form the roof rafters 216b, 218b. This alternative embodiment preferably uses bent flashing along the outside roof edge (external wall flashing 280) and the inside roof edge (internal wall flashing 282) on both sides of the roof to join the panels to the wall panels 300 as illustrated in Figure 22(a). Also, the flashing preferably is used above (external ridge flashing 284) and below (internal ridge flashing 286) the roof ridge to join and secure the panels together as illustrated in Figure 22(b). The internal flashing preferably also connects to an internal ridge joist 212c, which preferably is a C stud with its channel directed towards the floor. The ridge joist 212c preferably forms the top portion of a support panel 210c running vertically down the center of the house above the interior wall panels. The support panel 210c preferably is of a similar construction to the floor panels 200 except for having the end caps running in the vertical direction to serve as king posts along with the other crossing beams 216c, 218c. The other difference is that the support panel 210c preferably is not as tall as the floor panel is wide. Preferably, the flashing 280, 282, 284, 286 is bolted, screwed or welded to the appropriate panels 300, 210b, 210c prior to installation of the roofing material.
Under either of the above alternative roof constructions or other similar structures, the galvanized steel sheets 230 used as part of the flooring may also be used as the roofing material as illustrated in Figures 23(a)-(b). Alternatively,
1/55518
other types of roofing material may be used, which in turn will increase the cost of construction of the structure. This ability to select the type of roofing material is one of the advantages and flexibility offered by this invention.
An alternative embodiment is to eliminate the footings and floor substrate and instead begin with a concrete slab for the foundation. The wall panels and columns would then be attached to the concrete slab. Preferably in this alternative embodiment, the concrete slab would include the reinforcing bars and straps that connected the pillars of the footings through the floor beams to the columns. VI. Industrial Applicability
The above-described invention may be used to construct buildings of various sizes and designs. Particularly, this invention provides an inexpensive construction cost to build homes that will withstand high winds that accompanying hurricanes, monsoons, and tornados along with any driving rain that may accompanying these weather disturbances.
The design of the building materials using formed coiled steel increases the strength of the resulting building structure particularly when the studs are notched and combined with a concrete slab and the above-described columns provides unsurpassed price to strength ratio that is not possible with exclusively wood framing, solid concrete structures, or rectangular steel framing.
If the wall and floor panels are built off-site the preferable way to secure the joints between studs is with welding. If the wall and floor panels are built on-site at the building construction worksite, then the preferable way to secure the joints is with self-tapping screws. In light of the foregoing description, one of ordinary skill in the art will appreciate that there are other ways to secure these joints including bolting. Alternatively, bolting may be used to secure individual wall and/or floor panels to adjacent panels and/or columns.
Those skilled in the art will appreciate that various adaptations and modifications of the above-described preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.
We claim:
1. A lightweight steel frame for a building comprising: a plurality of footings each having a base and a column rising from said base; at least one floor panel cover having first and second header joists each having a main wall with two members extending from said main wall with each member having a flange to form a C cross-section channel, said first and second header joists being parallel to each other with the respective channels facing each other, said first and second header joists have a plurality of space notch pairs in respective flanges, and a plurality of beams each having a main wall with two members extending from said main wall with each member having a flange to form a C cross-section channel, each of said beams fits into a respective notch pair in said first and second header joists such that said beam is perpendicular to said header joists; a plurality of columns having two vertical members each having a main wall with two members extending from said main wall to form a U cross-section channel, a first flat piece connected to each of said two vertical members such that the channels of said two vertical members face each other, said first flat piece extends below said vertical members to attach to said floor panel, and a second flat piece connected to each of said vertical members such that a substantially rectangular channel is formed; a plurality of wall panels each having a floor member having a main wail with two members extending from said main wall with each member having a flange to form a C cross-section channel, said floor member having a series of spaced notch pairs along its length including a notch pair at its ends, two border members each having a main wall with two members extending from said main wall with each member having a flange to form a C cross-section channel, each of said border members fits into one of said notch pairs at the end of said floor member and extend perpendicular to said floor member,