Construction Joist and Joist Assembly

Description

RELATED APPLICATION

The present disclosure claims the filing priority of U.S. Provisional Application No. 63/560,528, titled “Construction Beam and Beam Assembly” filed on Mar. 1, 2024. The '528 application is also hereby incorporated by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a construction joist, joist assembly, and roof and floor construction for a building. More specifically, the invention relates to a joist construction and assembly for constructing components of a non-combustible building structure, such as a house.

BACKGROUND OF THE INVENTION

Wildfires are a major cause of home damage in many areas of the U.S., particularly in the western states. According to an article in Scientific American (“Wildfires Threaten More Homes and People in the U.S. Than Ever Before”, by Stephanie Pappas, Scientific American (a division of Springer Nature America, Inc.), Nov. 9, 2023), the increase in home damage is the result of an increased expansion of building into “wildland urban interface,” or WUI, which it describes as anywhere houses butt up against natural areas.

Grassland fires have been responsible for some of the most devastating losses in recent years. Most recently, from Jan. 7 to Jan. 31, 2025, a series of eight destructive wildfires affected the Los Angeles metropolitan area and San Diego County in California. In Los Angeles County, a report from the UCLA Anderson Forecast estimates that the two largest wildfires from that event—i.e., the Palisades and Eaton fires-caused total property and capital losses ranging between $95 and $164 billion, with insured losses estimated at $75 billion. There have been 29 deaths attributed to those fires. In the fire that leveled the Hawaiian town of Lahaina (August 2023), strong winds aided the fire that tore through hillsides of invasive grasses—and became an urban conflagration that destroyed more than 2,000 structures and killed at least 99 people. In December 2021, the Marshall Fire in Colorado's Boulder County destroyed more than 1,000 buildings and killed two people as it jumped from grasslands to suburban neighborhoods.

As illustrated in the graph of FIG. 1, both the area burned (grey area) and the number of homes (black bars) within the perimeter of such fires has increased significantly since 1990.

As the desire for a wildland urban interface for homes grows, so does the risk of fire damage. And, because the typical family home is built using a high percentage of combustible materials, such as wood, wallboard, and the like, the threat of complete loss due to a fire is very high. Accordingly, there needs to be a way to build houses close to nature, while minimizing the threat of fire damage and calamity.

Home builders and home buyers have turned to looking for homes built with less combustible materials. At present, there are homes that are built with steel framing (not very common) and homes that are built with Insulated Concrete Forms, but they also have to use wood framing, particularly on interior load-bearing walls.

California building codes, which are probably the most restrictive of any in the United States and possibly in the World, defines “Type 1A Non-Combustible” homes in Chapter 6 of the California Building Code 2019 (and International Building Code (IBC) 2018). However, there are no Type I-A single family homes being built. The regulations are very strict and present a difficult requirement to meet. For example, structural walls in a home need to have a minimum 3-hour fire rating, floors a 2-hour rating, and a roof must have a minimum 1.5-hour fire rating. These are very difficult requirements to meet cost-effectively, and literally impossible using wood materials.

Accordingly, a system and method are needed which allows for cost-effective compliance with strict building codes to achieve Type 1A Non-Combustible homes for those living in areas at risk of wildfires. Until the invention of the present application, these and other problems in the prior art went either unnoticed or unsolved by those skilled in the art. The present inventions provide an effective construction joist and building method which achieves multiple goals, including fire resistance, without sacrificing design, style, or affordability.

SUMMARY OF THE INVENTION

There is disclosed herein an improved construction method, including a unique roof and floor framing assembly which avoid the disadvantages of prior construction framing assemblies while affording additional structural and operating advantages.

Generally speaking, the steel construction joist has a 16-inch height and is used for building single-family homes in compliance with Type 1A non-combustible definition in Chapter 6 of the California Building Code (CBC).

The roof and floor framing assemblies include a plurality of steel joists bolted directly to opposing load-bearing walls, and spaced approximately 96 inches apart, a plurality of stiffener flanges may be used on the joists, as well as a plurality of steel braces arranged to connect adjacent joists. A plurality of insulated steel panels perpendicular to and covering the plurality of steel joists and bracing completes the assembly construction. A spacing of 4 to 8 feet between joists provides substantial room for the addition of mechanicals and lighting.

In specific embodiments, the joists may span a distance of 15 to 32 feet between load-bearing support walls. Finally, the plurality of steel joists is arranged perpendicular to the direction of slope for a roof.

These and other aspects of the invention may be understood more readily from the following description and the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of facilitating an understanding of the subject matter sought to be protected, there are illustrated in the accompanying drawings, embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages should be readily understood and appreciated.

FIG. 1 is a graph reproduced from “Rising Wildfire Risk to Houses in the United States, Especially in Grasslands and Shrublands” by Volker C. Radeloff et al., in SCIENCE, vol. 382 (Nov. 9, 2023), showing the impact of wildfires;

FIG. 2 is a perspective view of an embodiment of the disclosed joists and framing assembly as they would be used for constructing a Type 1A non-combustible home;

FIG. 3A is a front view of an embodiment of a knife plate used to bolt the disclosed joist to loadbearing outer walls;

FIG. 3B is a side view of the knife plate of FIG. 3A;

FIG. 3C is a top view of the knife plate of FIG. 3A;

FIG. 4 is a cut-away side view of an embodiment of the disclose joist bolted to an outer support wall using an embodiment of the knife plate of FIG. 3A;

FIG. 5A is a front view of an embodiment of a knife plate used to bolt the disclosed brace to loadbearing outer walls;

FIG. 5B is a side view of the knife plate of FIG. 5A;

FIG. 5C is a top view of the knife plate of FIG. 5A;

FIG. 6 is a cut-away side view of an embodiment of the disclosed brace bolted to an outer support wall using an embodiment of the knife plate of FIG. 5A;

FIGS. 7 and 8 are views showing placement of an embodiment of a plurality of roof joists between two load-bearing walls in a home construction;

FIGS. 9 and 10 are views showing placement of an embodiment of a plurality of bracing used in a construction similar to FIG. 2;

FIG. 11 is a cut-away view of a construction showing embodiments of the disclosed floor assembly and roof assembly;

FIGS. 12 and 13 are views illustrating placement of lighting and mechanicals in a construction similar to FIG. 2;

FIGS. 14 through 16 are views illustrating placement of reinforcement to a construction similar to FIG. 2; and

FIGS. 17 through 20 are views illustrating placement of an embodiment of a plurality of insulated roof panels to a construction similar to FIG. 2.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail at least one preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to any of the specific embodiments illustrated. The use of a “joist” is well-known in the construction industry and, in some instances, may also be referred to as a “beam.” Similarly, “braces” or “bracing” as used herein may also be referred to in the industry as “purlins.”

Referring to FIGS. 2-20, there is illustrated a housing construction joist and assembly, generally designated by numerals 10 and 12, respectively. Roof joists, referenced as 10A, and floor joists, referenced as 10B, are otherwise indistinguishable and often referenced collectively as joist 10. Likewise, a roof assembly 12A and floor assembly 12B, are often collectively referred to as assembly 12. The disclosed and illustrated joist 10 and assembly 12 is for constructing single-family Type 1A Non-Combustible homes in accordance with Chapter 6 of the California Building Code 2019 (and IBC 2018). However, while all the embodiments illustrated are directed to roof and floor construction for a single-family home, it should be understood that the principles of the invention can be more broadly applied to most dwellings, as well as other types of buildings.

With reference to FIG. 2, joist 10 is constructed of a steel material, preferably a steel material having a high-tensile strength and outer walls 20 are comprised of a reinforced concrete. Preferably, each joist 10 is approximately 16 inches in height and spans from a first loadbearing reinforced concrete wall 22 to a second loadbearing reinforced concrete wall 24. Joists 10 are preferably bolted directly to each outer concrete wall 20 and spaced apart a distance in the range of from 4 feet (48 inches) to 8 feet (96 inches). The actual spacing between adjacent joists 10 used in each construction should be determined based on load-bearing requirements of each joist 10, as would be known in the art. In the preferred embodiment, each joist 10 can span up to 32 feet—from a first to a second loadbearing concrete wall, 22 and 24, respectively. The most common span expected for each joist 10 falls in the range of 15 to 28 feet, more specifically in the range of 20 to 26 feet. Of course, shorter spans below 15 feet are contemplated where the loadbearing walls are a shorter distance apart, for example. These long spans between support walls allow interior walls to be constructed from lightweight metals instead of reinforced concrete, which saves considerable time and money in construction.

Referring to FIGS. 3-8, the joists 10 are bolted directly to an outer concrete wall 20 using unique knife plates 40A and 40B. The knife plate 40A, as illustrated in FIGS. 3A-3C, is comprised of four half-inch studs 42 extending perpendicularly from a first side of a base plate 44, and a flange 46 extending from a second (opposite) side of the base plate 44. The studs 42 of the knife plate 40A are embedded in an outer concrete wall 20, as shown in FIG. 4, to allow a joist 10A to be bolted to the flange 46. Similarly, a brace knife plate 40B is used for securing braces 30 to outer concrete walls 20 as well. The knife plate 40B, as shown in FIGS. 5A-5C, is comprised of four half-inch studs 42 extending perpendicularly from a first side of a base plate 44, and a flange 46 extending from a second (opposite) side of the base plate 44. The studs 42 of the knife plate 40B are embedded in the outer concrete wall 20, as shown in FIG. 6, to allow braces 30 to be bolted to the flange 46.

As shown in FIGS. 7-10, each roof joist 10A may be constructed with stiffener flanges 28 to provide rotational stability when used for roof slopes up to 4:12. Further, as shown in FIG. 11, roof joists 10A are arranged to run perpendicular instead of parallel to the direction of roof slope. Metal braces 30 may also be positioned to connect between adjacent roof joists 10A (as well as floor joists 10B) in most applications.

As illustrated best in FIGS. 12 and 13, the joist assembly 12 provides adequate room for mechanical and lighting installation, as no batting is required. The joist 10 enables framing and roofing of a house in about one-third of the time that it normally takes using wood materials. This labor efficiency provides a direct cost savings. As previously noted, the preferred eight-foot spacing between joists 10 and no batt insulation means that there is plenty of clear space for HVAC, lighting fixtures, plumbing, electrical wiring, and fire sprinklers-unlike wood framing having 12″-24″ joist spacing and fiberglass batt requirements causing all the trades to compete with one another for adequate space. The result of using wood framing by comparison is messy and time consuming.

Steel structural roof panels 32 are shown completing the construction in FIGS. 17-20. The use of insulated standing seam metal roof panels 32 provides further resistance to lateral forces, thereby eliminating the need for structural sheathing. In turn, the elimination of structural sheathing enables far greater cost-effective construction of an entirely wood-free residential roofing assembly 12A. Where a floor assembly 12B is constructed, composite decking 34 is preferably used to complete the construction. The composite decking 34 is comprised of steel sheeting with a topping of 3,000 psi lightweight concrete. Obviously, other floor materials may be suitable, so long as they meet requirements for non-combustible construction materials.

The disclosed invention further includes constructing a non-combustible single-family home in compliance with the California code. Beginning with the erection of outer walls 20, these are made from reinforced concrete. These outer walls 20 become the primary load-bearing structures for the home. At each level or story, a floor assembly 12B is built in accordance with the above description. When constructing a home of multiple stories (i.e., two or more stories), it will be necessary to build up the outer walls 20 after each of the multiple floor assemblies 12B is built. A final outer wall construction supports the roof assembly 12A, as shown and described.

In this manner, the joist assembly 12 helps realize a non-combustible minimum 1.5-hour fire rated roof assembly 12A and a 2-hour fire rated floor assembly 12B for a single-family home. The joist assembly 12 eliminates the need for structural sheathing, where plywood is the only feasible sheathing option for single-family homes. Without the disclosed joist 10 and joist assembly 12, building a Type I-A home would be so expensive that it would not be feasible.

The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of applicants' contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.