Patent Application
20180202161
The present invention relates to a reinforcing plate for sistering joist and a method of sistering the joists. In particular, the invention relates to a reinforcing plate for attaching to wood joists to enhance the structural integrity of the joists and the method related thereto.
Over time, joists lose some of their resiliency and tend to sag. This results in floors that also sag or become bouncy as people walk over them. Even new homes built to proper code will have some deflection, particularly if joists must span long areas. Joists push down or deflect slightly with weight and then spring back upward after the weight moves. The joists need further stiffening to relieve the up and down motion.
In addition, in existing structures, it is often the case that the integrity of joists has been compromised due to the improper drilling or cutting of the joists incurred during initial construction or previous renovations. Older buildings were often “under structured” utilizing joists that were wide by insufficiently deep to carry live and dead loads without sagging over time. In such cases, the joints need to be reinforced to provide the structural integrity required to support the structure.
Structural lumber used throughout the world for constructing buildings is available on the market in a plurality of forms and wood species. However, due to the orthotropic properties of wood, some species cannot be used efficiently in many applications and/or under particular conditions. Also, visual grading of structural lumber using as criteria exterior wood appearance restricts the use of an important quantity of slightly affected structural lumber to applications in which the stresses involved are considerably lower. A considerable amount of structural lumber is also discarded due to natural imperfections such as shrinkage, cracks, knots, orientation of the fibers, warping, etc.
It would be beneficial to provide a joist sistering plate and method which can be used to provide additional structural integrity to existing wood joists. In addition, it would be beneficial to provide such a joist sistering plate and method which can be used with new construction and with existing or old construction.
An object is to attach a plate made of metal or similar material to a joist to enhance the structural integrity of the joists.
An object is to provide a plate which can be used in new construction or which can be used in existing construction.
An object is to provide a plate which has predrilled holes, allowing for various types of conduits to be easily inserted through the plate.
An embodiment is directed to a reinforcing plate for use in sistering to a wood member to create a composite floor joist. The reinforcing plate includes preformed first openings and preformed second openings. The preformed first openings are provided proximate to edges of the reinforcing plate and are dimensioned or configured to allow for attachment members to be inserted therethrough to attach the reinforcing plate to the wood stud/joist. The preformed second openings are larger than the first opening and are dimensioned to allow for building materials to extend therethrough. The reinforcing plate resists bending stresses and increase the shearing resistance of the wood stud/joist.
An embodiment is directed to a joist or stud used to support a structure. The floor joist includes a wood member and a rigid reinforcing plate. The wood member has a first surface and an oppositely facing second surface, end surfaces extend between the first surface and the second surface, edge surfaces extend between the first surface, the second surface, and the end surfaces. The rigid reinforcing plate is mounted to the first surface of the wood member. The rigid reinforcing plate has longitudinal edges positioned proximate to or adjacent to the edge surfaces of the wood member. The rigid reinforcing plate includes preformed first openings spaced from the longitudinal edges, the first openings allow for building materials to extend therethrough. The longitudinal edges of the rigid reinforcing plate do not cooperate or interfere with the edge surfaces of the wood member. The reinforcing plate is mounted to the wood member to resist bending stresses applied to the floor joist and to increase the shearing resistance of the floor joist.
An embodiment is directed to a method of sistering a joist or stud. The method includes: mounting a first rigid reinforcing plate to a first surface of a wood member; and inserting pipe and/or electrical conduit through preformed first openings provided in the first rigid reinforcing plate, the first openings being spaced from longitudinal edges of the first rigid reinforcing plate, the longitudinal edges of the first rigid reinforcing plate do not cooperate or interfere with edge surfaces of the wood member. The first rigid reinforcing plate is mounted to the wood member to resist bending stresses applied to the floor joist or stud and to increase the shearing resistance of the floor joist or stud. The method may optionally include adhering the reinforcing plate to the wood member with an adhesive to form a composite floor joist, inserting mounting members through preformed second openings provided proximate the longitudinal edges of the first rigid reinforcing plate to form a composite floor joist, or both.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
The description of illustrative embodiments according to principles of the present invention is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments of the invention disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation unless explicitly indicated as such. Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Moreover, the features and benefits of the invention are illustrated by reference to the preferred embodiments.
Accordingly, the invention expressly should not be limited to such preferred embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features, the scope of the invention being defined by the claims appended hereto.
As best shown in
The wood or joist member 12 has a first surface 16 and an oppositely facing second surface 18. The wood member 12 also has end surfaces 23, 25 and edge surfaces 24, 26. The end surfaces 23, 25 extend between the first surface 16, the second surface 18, the edge surface 24 and the edge surface 26. The edge surfaces 24, 26 extend between the first surface 16, the second surface 18, the end surface 23 and the end surface 25. In the embodiment shown in
In the embodiments shown in
In accordance with the present invention, the reinforcing plate 14 is fixedly secured to the wood member 12 of the joist 10. To fixedly secure the reinforcing plate 14 to the wood member 12 of the joist 10, the reinforcing plate 14 is formed at predetermined intervals and throughout the length thereof with preformed openings 28 which are dimensioned to receive attachment members 30, such as screws or through bolts, therein. The openings 28 are dimensioned to allow the thread of the screws to pass through the opening 28 and to be driven into the wood member 12. The heads of the screws have a larger diameter than the openings 28, thereby allowing the screws 30 to properly secure the reinforcing plate 14 to the wood member 12. In addition to, or alternatively, other fixation means such as bolts, nails, formed teeth, adhesive, etc. may also be used. Regardless of the type of fixation, it should be understood that very strong fixation of the reinforcing plate 14 to the wood member 12 of the reinforced floor joist 10 substantially over the entire length of the reinforcing plate 14 is required to enable the reinforcing plate 14 to carry out its function, that is, strengthening the wood member 12 of the joist 10. In various embodiments, the securing members 30 may be positioned in each opening 28. In other embodiments, securing members 30 may be positioned in a plurality of openings 28, with no securing members 30 being positioned in other openings 28. In various embodiments the reinforcing plate 14 may also be adhered to the wood member 12 with an adhesive to form the composite reinforced floor joist 10.
Alternatively, as shown in
The reinforcing plate 14 includes openings 40. The openings 40 are dimensioned to be larger than openings 28 to allow for electrical wiring, plumbing, conduit or other materials or devices to extend therethrough. In the embodiments shown, the openings 40 are spaced periodically along the entire length of the reinforcing plate 14. In some embodiments, the openings 40 are spaced equidistant from each other. However, other configurations and positioning of the openings 14 may be used. Regardless of the configuration, the openings 40 must be spaced and or positioned to allow sufficient material to be provided across the length and width of the reinforcing plate 14 so that the integrity and performance of the reinforcing plate 14 is maintained or not drastically reduced, thereby allowing the reinforcing plate 40 to support or resist the bending stresses applied to the joist 10 without failure of the reinforcing plate 14 or the reinforced floor joist 10.
The openings 40 in the representative illustrative embodiments are round. However, the openings 40 may be oval, rectangular, square or other shapes without departing from the invention. The size of openings 40 may vary according to the application and size of the reinforcing plate 12. For example, the height of the openings 40 may be no more than ⅔ of the height of the reinforcing plate 14, may be no more than ½ of the height of the reinforcing plate 14, may be no more than ⅓ of the height of the reinforcing plate 14.
The openings 40 are provided to allow for each of installation of the electrical wiring, plumbing, conduit or other materials or devices therethrough. As the gauge of the material used for the reinforcing plate 14 must be sufficient to stabilize the wood member 12 by resisting bending stresses and the like, it may be difficult to properly drill through the reinforcing plate 14 to accommodate the electrical wiring, plumbing, conduit or other materials or devices. By providing the openings 40, drilling of the reinforcing plate 14 is not required. In addition, as the positioning of the openings 40 is properly controlled in the reinforcing plate 14, improper location of the openings 40 which may occur during site drilling is eliminated, thereby ensuring the integrity of the reinforcing plate 14 and its ability to withstand the bending stresses and the like.
With the reinforcing plate 14 secured to the wood member 12, the reinforced floor joist 10 will act as a composite member to take advantage of the increased resistive properties of the reinforcing member 14. The composite reinforced floor joist 10 resists and transverse shear generated as a result of bending.
In use, the reinforced floor joist 10 is generally supported at its ends. If the reinforcing plate 14 is positioned in the central portion (as shown in
In the embodiment shown in
Although the above description is directed mainly to the reinforcement of joists (horizontal load bearing members) made of wood, the concept of the reinforcing plate 14 in accordance with the present invention is also applicable to any other type of elongated structural wood members, for example studs (vertical load bearing members) and other members used for constructing the walls, trusses and other structures of a building. For example, the concept of the reinforcing plate 14 may be used to reinforce elongated structural wood members subjected to direct tension, or to direct compression, direct shearing and any combination thereof. It is also within the scope of the present invention to use the reinforcing plate 14 to reinforce any type of reconstituted wood.
The reinforcing plates 14 can be easily installed on the site to reinforce an already erected structure to improve its structural resistance. This allows wood members or joists which have been compromised by improper notching or drilling to be reinforced without the need of using an additional wood joist for sistering. As the reinforcing plate 14 is mounted to the side surfaces of the existing wooden horizontal joist, the reinforcing plate 14 does not engage or interfere with the top and bottom edge surfaces of the joist. Consequently, as the top and bottom edge surfaces are not altered or compromised, conventional construction methods can still be used for building the floor and ceiling.
Using the reinforcing plates 14 in the manner described above compensates for natural defects in wood, such as, but not limited to: shrinkage; cracks; localized weakness caused by knots; skips; checks and shakes; resin pockets; pulled grain; grain deviation; holes; decay; warping; and curvature. In addition, the reinforcing plates 14 reinforce the periphery of any opening made into the elongated structural wood member for passing electrical wires, plumbing or other conduits.
Use of the reinforcing plates 14 also protects against deflection, shearing and dampens the vibratory and oscillatory phenomenon inherent to the long span floor structures.
With new joists, the reinforcing plates 14 allow the wood member 12 to be smaller in width and thickness than previous wood members, while still maintaining the load capacity and structural integrity required. For example, the use of the reinforcing plates 14 allow the width and thickness of the wood member 12 to be reduced by 10% or more, thereby saving large quantities of wood. The loss of mechanical properties caused by the reduced width and thickness of the wood member 12 is compensated by the reinforcing plates 14. In addition, woods of less quality can be used, as the reinforcing plates 14 provide the mechanical properties required.
In the above description, the reinforcing plates 14 are made of sheet metal. It is within the scope of the present invention to use metals or metallic alloys other than steel. Additionally, while illustrative embodiments of the reinforcing plate 14 are shown, the reinforcing plate 14 may have different shapes, widths and/or thicknesses without departing from the scope of the invention.
The method of sistering the wood member 12 and reinforcing plate 14 to form a composite floor joist 10 includes the steps of: mounting a rigid reinforcing plate to a wood stud by inserting mounting members through preformed first openings provided proximate to edges of the reinforcing plate; and inserting conduit, such as pipe and/or electrical wiring, through preformed second openings provided in the reinforcing plate. Wherein the reinforcing plate is mounted to the wood stud to resist bending stresses applied to the floor joist and to increase the shearing resistance of the floor joist. The method may optionally include adhering the reinforcing plate to the wood stud with an adhesive to form a composite floor joist.
To understand the concept of reinforced wood, one should know that most wood species are weaker in tension than in compression. When wood is reinforced, the tension and compression stresses are supported by the metal of the reinforcing plate 14 to improve the mechanical performance of the wood member. Use of reinforcing plate 14 will easily multiply the resistance of an elongated structural wood member to compression, tension, bending, crushing and shearing by 1.5 or more.
As an example, joist members made of wood of identified species and with no reinforcing plate were tested by calculation to find the maximum allowable loads each member could support over various spans without yielding. Next, joist members made of wood of the same identified species and with one reinforcing plate were tested by calculation to find the maximum allowable loads each member could support over various spans without yielding. Finally, joist members made of wood of the same identified species and with two reinforcing plates, with one reinforcing plate on either side of the wood, were tested to find the maximum allowable loads each member could support over various spans without yielding. The following table displays the percent increase in load capacity from the original member with no reinforcing plate to a member with one reinforcing plate and from the original member with no reinforcing plate to a member with two reinforcing plates.
In addition to providing load capacity increases obtained from the composite beam, equivalent beam depth or height values are calculated from the maximum load capacities. The following table displays the effective equivalent beam depth increases in inches.
This demonstrates the advantages of using a composite beam to add additional load resistance to a wood stud or member. The load capacity increases are substantial, in the case of Hemlock and Spruce, tripling the amount of load the beam can be subject to. This method of reinforcing a structural member has the added benefit of relative ease of manufacture and production, along with being an environmentally friendly substitute for creating high strength joist members in lieu of using only wood. In the case of a two-sided Hemlock or Spruce 2×8′ composite member spanning 12 feet, 750 in3 of wood is saved by utilizing the composite as opposed to the equivalent wood only member.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention as defined in the accompanying claims. In particular, it will be clear to those skilled in the art that the present invention may be embodied in other specific forms, structures, arrangements, proportions, sizes, and with other elements, materials, and components, without departing from the spirit or essential characteristics thereof. One skilled in the art will appreciate that the invention may be used with many modifications of structure, arrangement, proportions, sizes, materials, and components and otherwise, used in the practice of the invention, which are particularly adapted to specific environments and operative requirements without departing from the principles of the present invention. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being defined by the appended claims, and not limited to the foregoing description or embodiments.
| Number | Date | Country | |
|---|---|---|---|
| 62447586 | Jan 2017 | US |
