This invention relates to the construction of a budding using Braced Frame Slab Assemblies Having Heavy Perimeter Rails that comprise Floor Slabs and Wall Slabs formed of heavy perimeter Rails, with Rail Frame Connectors joining the heavy perimeter Rails to form the Floor Slabs and Wall Slabs. Slab to Slab Connectors also secure juxtaposed Floor Slab and Wall Slabs. The structurally interconnected Slabs provide the required structural capacity for the building to resist high lateral shear loads. The prefabricated braced frame Floor Slabs and Wall Slabs can be placed into the building under construction using a crane or other load lifting mechanism.
In the prior art, the stick-built building is a product that is either custom built according to individual specifications, or as a builder's spec, or constructed as one of a plurality of pre-existing models in a housing development. These buildings are built in the traditional manner of using framing members (typically dimensional lumber or steel framing members) to fabricate the building on a foundation at the building site according to a set of architectural plans.
A wall, in the stick-built building, is formed with a bottom plate that rests on the underlying structural component of the building, such as a concrete foundation. The basic light-frame wall of stick-built construction is a plurality of vertically-disposed studs connected to the bottom plate, and a top plate or double top plates that are supported by and connect to the vertically-disposed studs. Openings for windows and doorways may be incorporated into the light-frame wall. There is a need for shear resistance in a wall, but large openings reduce the lateral (shear capacity) of the wall. In the past, one of the earliest methods for bracing a wall against lateral forces was to incorporate bracing into the frame of the wall in the form of diagonal bracing members. However, this solution is limited by the placement of windows and doors. Another simple means of providing lateral resistance is to provide sheathing to the frame. Plywood sheathing and Oriented Strand Board (OSB) are common sheathing materials used today in conventional light-frame construction to provide shear capacity in a wall to resist lateral loads.
Stick-built design differs greatly from the modular and manufactured design of road shippable products. There are few architectural, structural or dimensional limitations with stick-built buildings like those imposed on modular and manufactured design by virtue of the roadway transportation limitations of manufactured structures. Transportation over public roads involves height, width, length and weight restrictions. In stick-built construction, the characteristics of: height, width, depth, roof pitch, roof overhang, gabled, dormered, etc. are all completely open to individual tastes limited only by the governing building code restrictions. For example, the ability to produce standard size buildings with substantial design flexibility is the reason that the majority of homes built today are stick-built homes.
Stick-built construction requires a sequenced building format, where item A must be completed before item B can begin, and in turn, item B must then be completed before item C can begin and so on. For example, the ground level walls must be completed before the second level floor can begin, and the second level walls must be completed before the second level ceiling can begin. While this method of construction has worked for many years, there are inherent inefficiencies in this method that result in significant cost penalties to the building buyer.
As light-frame construction design became more sophisticated, more robust foundation anchors were added to connect the floor and wall pieces to the foundation. It is also realized that certain walls would lift up under moment reactions caused by lateral forces and so the walls needed to be further anchored with brackets called hold-downs, which attach to the studs of the wall and to anchors set into the foundation. With proper design and installation, these conventional methods of providing lateral resistance by applying sheathing, foundation anchors and anchored hold-downs to conventional walls can provide acceptable resistance to most lateral forces. However, proper installation can be a problem using conventional methods. The division of labor on job sites can result in improper connections. Furthermore the installer may cut corners and sacrifice resistance to lateral forces in return for ease of installation or aesthetic considerations.
One prior art system to address this lateral shear load problem is disclosed in U.S. Pat. No. 8,479,470 which teaches a wall in a light-frame building, having within it a sub-component specifically designed to resist lateral forces imposed on the building, such as those caused by an earthquake or by wind loading. A shear-resisting assembly has top and bottom struts and first and second chords and a planar shear resisting element connected thereto. The shear-resisting assembly is connected to the top plate of the wall and is also connected to the underlying structural component. These connections allow lateral forces on the top plate of the wall and on the underlying structural component to be transmitted to the shear-resisting assembly.
The above described problems are solved, and a technical advance is achieved, by the Building Construction Using Braced Frame Slab Assemblies Having Heavy Perimeter Rails of the present invention. This invention relates to the construction of a building using Floor Slabs and Wall Slabs that are formed of heavy perimeter Rails, with Rail Frame Connectors, such as a plurality of heavy threaded screws, joining the heavy perimeter Rails together to form the outside extent of the Floor Slabs and Wall Slabs, each enclosing a predetermined space. The Slab Assembly can then be equipped with joists for floors or studs for walls, and with structural sheathing to provide additional sheer load carrying capacity.
The Slab to Slab Connectors structurally secure juxtaposed Floor Slabs and Wall Slabs to each other. They tie each Slab Assembly to adjoining Slab Assemblies at any location along their juxtaposed Heavy Perimeter Rails by interconnecting the Heavy Perimeter Rails that form the perimeter of Wall Slabs and Floor Slabs. The Floor Slabs are connected to the foundation. The Wall Slabs rest on and are connected to heavy perimeter Floor Slabs by their respective Heavy Perimeter Rails, so all structural loads on the building are transferred to the foundation. The structurally interconnected Slab Assemblies provide the required structural capacity for the building to resist high lateral shear loads. The prefabricated braced frame Floor Slabs and Wall Slabs can be placed into the building under construction using a crane or other load lifting mechanism. These Floor Slabs and Wall Slabs can be constructed on site or manufactured in a factory to include utilities, windows, fitted up components installed in the factory, which avoids the impacts of weather, and on site limitations.
The Rail Frame Connectors and the Slab To Slab Connectors look the same, and they are typically close in size to each other. Functionally, they are 100% different from each other at a strategic level of importance, and this is the reason they are named separately and described independently, herein. At its most basic level, there are both Floor Slabs and Wall Slabs with two realities. First, all Slabs have heavy perimeter Rails. Second, all of the Slabs in a building are structurally interconnected with one another to create full building shear capacity. The heavy perimeter Rails present in all Slabs is the means, in the second case, of interconnecting all the Slabs for the full structural integrated frame of the resultant building.
The Rail Frame Connectors are large screws used to attach the heavy perimeter Rails to one another in a single Slab. They can alternatively be large nails to attach adjacent heavy perimeter Rails to one another in a single Slab. They serve a straightforward purpose to build a Slab with a heavy perimeter Rail to enclose a predetermined space.
In contrast, the Slab To Slab Connectors are totally different in function. A performance criteria of huge importance in a structure is that the whole floor, and whole, complete walls, each function as full shear elements (full walls as an integrated shear element, and concurrently full floors as an integrated shear element). The most basic and universally adhered to detailing for this, in conventional framing, is for OSB or plywood sheathing in an “brick like” pattern such that the whole floor or whole wall behave as a singular structural body. The “brick like” pattern of the OSB sheets, where the edges of the OSB sheets fall over the joists below in a floor or the studs behind in a wall, structurally eliminate the effect of the OSB edges because the shear loads transfer sheet-to-sheet through the studs behind or joists below and the whole floor or wall is effectively “one shear plane”. This is all-important, and buildings would fall down in the first wind storm if not for this.
In a pre-fabricated approach to housing design and construction, where elements of the house are manufactured off site and then shipped to the job as smaller pieces, the biggest structural challenge is, “how do you end up with full floor and full wall integrated shear capacity when you are working with “not full size” floor and wall elements with major discontinuities of structure between them?” The total structure, when complete, has to resist lateral loads, but seemingly the #1 rule was violated in framing with major structural discontinuities within both the full walls and the full floors.
This sets up the unique, non-obvious, critical, performance function of the Slab To Slab Connectors. These diagonally installed heavy fasteners are capable of high load capacity attachment because heavy perimeter Rails are provided on both sides. The Slab To Slab Connectors attach Floor Slabs to adjacent Floor Slabs to create the same total integrated full floor shear capacity as the “brick like” sheathing pattern in customary stick construction, despite the seemingly crazy condition of total structural independence of 4-8 Floor Slabs (where the all-important full floor shear diaphragm appears impossible). The same consideration is present with the full walls in that the Slab to Slab Connectors integrate multiple Wall Slabs into a comprehensive total wall shear element. The same consideration is also present with the connection of multiple Floor Slabs in a total floor, to multiple Wall Slabs in total walls, in that the diagonally installed Slab To Slab Connectors affix the whole set of Slabs together to be a proper shear integrated whole. The Slab To Slab Connectors achieve this, but only because all individual Slabs are detailed with heavy perimeter Rails such that substantial loading could be achieved in these limited number of connection points, in contrast to a multitude of “low load” connection points as is present with common nailing of studs in conventional construction.
Further, the Slab To Slab Connectors can penetrate finished walls on the inside with drywall installed on the Wall Slabs. A hole the size of a quarter would need to be patched later, which is no big deal. So the Slab To Slab Connector means of integrating pre-manufactured, Slab elements together results in both total structural performance AND the ability to complete Slabs to a substantial level of finish in the more efficient factory setting and still be able to make the basic structural frame attachments at a later time in the field.
The Slabs (also termed Slab Assemblies herein) can also further resist shear when they incorporate sheathing panels which provide shear capacity in the Slab Assemblies, but the sheathing does not have to be continuous across the full structure, since the Rail Frame Connectors and Slab to Slab Connectors create an adequate load path. The resultant Slab Assembly, for example, is a high performance shear element to transfer shear load incrementally along length of the Wall Slab and/or Floor Slab as if it was continuously sheathed even though it is not. The rigidized Slab Assemblies, optionally including the fitted up components, can be hoisted into position for insertion in the building under construction and later permanently attached to adjoining Slab Assemblies with Slab to Slab Connectors freely placed on common Heavy Perimeter Rails securing adjacent Heavy Perimeter Rails together to create a total shear box.
The sequential, mutually exclusive and disjunct subcontractor operations of the prior art can therefore be replaced with a partitioning of the construction process to functionally complete the construction of predetermined Slab Assemblies at a manufacturing facility. Thus, electrical, plumbing, insulation and the finishing may be started earlier than in the traditional stick-built building process while some operations, such as exterior siding, can be done from the exterior of the dwelling when the primary Slab Structure is in place.
Significant time savings can be attained since this subassembly operation is weather independent and Slab Assemblies or large subassemblies can be produced, and then moved with a plurality of hoisting devices. Additionally, significant material cost savings are realized due to an ability to bulk purchase materials and supplies directly from manufacturers without mark-ups to middlemen. Since shipment is also direct from the manufacturers to the manufacturing site, there is far less breakage and damage losses because material handling has correspondingly been reduced. Labor savings are achieved by the hoisting devices which enable a worker to move large quantities of raw materials from the delivery vehicles to storage areas integral to the production lines and hence into the shell of each dwelling being assembled. The manufacturing operation is executed within the environmentally controlled volume that is encompassed by the exterior shell of the manufacturing facility. The use of precision tools, preformed jigs, substantial hoisting devices and hydraulic assemblies are justified and cost-effective since large numbers of quality dwellings are being produced in a short time frame. The use of substantial hoisting devices in the manufacturing facility reduces the labor content, speeds up the manufacturing process as well as enables the use of heretofore nontraditional structural concepts.
Connectors—There are two classes of Connectors: Rail Frame Connectors and Slab to Slab Connectors. Rail Frame Connectors are the hardware, screws, bolts, plates or similar mechanical attachment means utilized to interconnect the heavy perimeter Rails that form the perimeter of Wall Slabs and Floor Slabs while the Slab to Slab Connectors structurally affix adjacent Slab Assemblies to each other, such that a structurally adequate load path is provided to transmit loads from one Slab Assembly to those adjacent to it.
Floor Slab—a pre-fabricated, framed floor component of interconnected perimeter Rails and equipped with joists. The Floor Slab derives shear strength from sheathing applied to the upper or lower surface, including the heavy Rails forming its perimeter, which is referred to as 2-Dimensional because of its slab-like configuration. Rail—the heavy perimeter member present in Slab Assemblies, attached to and reinforced by the sheathing applied to the Slab Assembly and either the floor joists (in a Floor Slab) or wall studs (in a Wall Slab), that enables the placement of Slab to Slab Connectors that structurally attach the Rails of adjacent Slab Assemblies to each other.
Slab Assembly or Slab(s)—either a Floor Slab, a Wall Slab, or both, attached to adjacent Slab Assemblies by freely placed Slab to Slab Connectors affixing the Heavy Perimeter Rails of each Slab Assembly to another Slab Assembly.
Slab Structure—a building assembled from Floor Slab and Wall Slab components.
Standard Size Dwelling—a “normal” or full size dwelling, presently produced onsite by means of stick building technology. This dwelling has an extensive range of design and floor plan flexibility and includes both one and two story single or multi-family structures.
Stick-Built Home—a dwelling built in the traditional manner of using dimensional lumber as framing members to fabricate the dwelling on a foundation at the building site according to a set of architectural plans which have available an extensive range of design and floor plan flexibility and includes both one and two story structures.
Wall Slab—a pre-fabricated, framed wall component of interconnected perimeter Rails and equipped with studs. The Wall Slab derives shear strength from sheathing applied to at least one vertical surface, including the heavy Rails forming its perimeter, which is referred to as 2-Dimensional because of its slab-like configuration.
The standard framing paradigm used in conventional construction is a “braced frame” structure where the bracing is provided via the OSB sheathing that covers the floors and walls once they are secured in place. Standard framing utilizes a uniform sheathing on both floors and walls (except at door and window openings) to create a braced frame (a.k.a. a diaphragm). The emphasis in this type of construction is the continuity of the OSB sheathing across the full extent of the wall and floor elements. For example, each of the parts in a wall frame is dedicated to a specific purpose—bottom plate, full studs, trimmer studs, headers, top plate, etc. There are no pieces in this structure that support another purpose—i.e. for the primary structural attachment of adjoining independent panelized components.
In contrast, the present Braced Frame Slab Assemblies Having Heavy Perimeter Rails incorporates heavy perimeter Rails for this purpose, which is a fundamental distinction over the standard framing described above. In the present Braced Frame Slab Assemblies Having Heavy Perimeter Rails, there is no need for surface continuity of the OSB panels, either in floors or walls. In fact, all of the Wall Slabs and Floor Slabs are interrupted with joints between adjacent Slab Assemblies. So shear continuity is achieved by the structural connection between independent Slab Assemblies via the interconnection of the perimeter “heavy” Rail frames of this framing system, because customary shear continuity to the edges of full floor and wall elements with continuous OSB is impossible. This is a non-obvious and novel means to create “braced frame” integrity in a whole structure. The Slab Structure does this by interconnecting completely independent Floor Slabs and Wall Slabs by joining their perimeter Rails to achieve the same end to end shear element functionality for the full walls and floors that is required.
Conventional, sequenced, individual trade based conventional frame construction “teaches away” from the present Building Construction Using Braced Frame Slab Assemblies Having Heavy Perimeter Rails. The goal of conventional framing is to minimize the cost of this individual aspect of the whole house—i.e. just the framing part alone. This is why there are no individual pieces that do not have relevance in the required elements for the whole, completed home. If there were such pieces, they would by definition be wasteful if one looked at the frame without consideration of the entirety of the construction more broadly.
In the present Building Construction Using Braced Frame Slab Assemblies Having Heavy Perimeter Rails, the frame not only provides the structural integrity for the finished structure, but it also is a primary means of streamlining many (otherwise) independent aspects of construction. Completed, closed-Wall Slabs can be made with the present Braced Frame Slab Assemblies Having Heavy Perimeter Rails, off foundation in a more efficient plant setting or on-site assembly area, so now incremental efficiency is gained in overall time as well as time, material and logistics related costs to install: electrical, insulation, drywall, siding, windows and doors, plumbing, etc.
The perimeter Rails are different and bigger than traditional framing elements, and serve a unique function that is not present in standard framing. They are also similar to one another, i.e. the Heavy Perimeter Rails in a Floor Slab serve the same purpose and are configured in the same perimeter arrangement as the Heavy Perimeter Rails in a Wall Slab, so the names that identify each unique piece carry a commonality with regard to the balance of related pieces.
The word “Rail” connotes a member of size and significance that is different than customary framing pieces in houses. A “Rail” is strong, and an identity element different than the pieces around it that enclose a predetermined space. It can be horizontal (in floors or in the top or bottom of a wall), or vertical (at the terminus of walls). All Wall Slab Assemblies have: a “Head Rail” or “Heavy Head Rail” at the top, depending on whether it was a Wall Slab without windows or one with windows; a “Toe Rail” at the bottom; “Wall End Rails” at the side of all Wall Slab. On Floor Slabs there are “Floor Edge Rails” on all four sides of all Floor Slab. In all instances of Wall Slab and Floor Slab creation there are Rails at the perimeter. In all instances of connection—of any two Slab Assemblies together—a Rail in one Slab is affixed to a Rail in an adjoining Slab. In traditional construction, framing typically uses dimensional lumber, such as 2″×4″ or 2″×6″ members to create the wall frames. In contrast, the present Braced Frame Slab Assembly Having Heavy Perimeter Rails makes use of Rail members that are heavy to provide a source of stability in the joining of the Wall Slabs and Floor Slabs. These Rail elements can be sawn lumber of greater dimensions than traditional framing members, or manufactured elements, for example, such as Glulam or VersaLam members manufactured by Boise Cascade, or even steel members. These “heavy Rails” provide the sound structure that allows the joining of Slab Assemblies in a secure, solid manner noted above. The Rails also enable the Wall Slabs and Floor Slabs to be capable of hoisting and handling without damage to the Wall Slabs and Floor Slabs and their installed components.
In
The interconnection of Wall End Rails 113 and 103 is preferably accomplished by the use of two screws in one location, at different angles from each other (90 degree offset is strongest), to lock that location in place at a high load capacity (as shown in
In the manner described above with respect to braced frame Wall Slab 100, braced frame Wall Slab 200 consists of a Heavy Head Rail 201 which spans the space between Wall End Rails 203, 204 which are affixed to Toe Rail 202. All of these Rails are members of size (dimensions) that are greater than used in conventional framing construction and/or of a material that is stronger than untreated lumber. The Heavy Head Rail 201 spans the distance between Wall End Rails 203, 204 and functions to rigidly interconnect these elements with the Heavy Head Rail 201 optionally being heavier than the Head Rail 101 noted above due the voids created by the presence of a window 206 and a door frame 205 to thereby provide additional rigidity to the Wall Slab 200. As noted above, the interconnection of Heavy Head Rail 201, Toe Rail 202 and Wall End Rails 203, 204 is accomplished by the use of countersunk long screws (not shown) which penetrate deeply into Wall End Rails 203, 204 to secure these elements together.
It should be noted that for large spans, typically, builders use an intermediate beam (not shown) in the middle of the floor structure, framing one side of Floor Slabs into it on both sides. In this way we create a largely column free space in the building and provide the necessary support for the floor.
The heavy perimeter Rail framing elements in the braced frame Wall Slab Assemblies are different and bigger than traditional framing elements, and serve a unique function that is not present in standard framing. They are similar to the Rails in the Floor Slab, i.e. the heavy perimeter members in a Floor Slab serve the same purpose and are configured in the same perimeter arrangement as the heavy perimeter members in a Wall Slab. The heavy perimeter is the connection element used to secure all Assemblies to one another, with the interconnection being effected by the use of specialty Slab to Slab Connectors that inherently create concentrated loads requiring the Heavy Perimeter Rails. The Slab to Slab Connectors are heavy threaded screws, freely placed at any location along the common Rail boundary between Slabs.
Filing Document | Filing Date | Country | Kind |
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PCT/US2019/049595 | 9/4/2019 | WO | 00 |