Patent Grant
8820034
1. Technical Field
The present disclosure relates generally to reduced thermal bridging across structures and building components. More particularly, the disclosure relates to reduced thermal bridge studs, plates, and other building components.
2. Background
Building codes in the United States, Europe, and elsewhere are becoming more and more restrictive with regard to energy use than in times past. It is anticipated that as time passes, many of the building codes will require more insulation, less air leakage, higher performance windows and doors, and other like components in order to reduce energy usage.
When used for framing, commonly-used 2×4s, 2×6s, 2×8s, 2×10s, 2×12s, etc. are typically made of solid wood. Such solid wood studs and plates may transfer significant heat energy through framed walls. Builders typically attempt to avoid thermal bridging by building double walls on the outer perimeter of buildings or by using other complicated framing configurations. This approach may be effective but can double the labor and material for framing. Builders typically may use complex methods to join the double walls at the top plate to roof interface to achieve structural integrity. This double wall approach can also be costly and time consuming.
In some cases, builders may also use single or multiple layers of rigid foam insulation on the outside of a building's sheathing to reduce thermal bridging. This approach can also be very labor intensive and the materials can be costly. Following the application of the rigid insulation, builders typically then install vertical battens that are used to attach the building siding. These vertical battens are attached to the building wall using long screws. This building approach is also typically costly and labor-intensive.
What is needed, therefore, is a building method that is less labor-intensive and less costly than the foregoing approaches, while resulting in a relatively low thermal bridge.
In one embodiment, a low thermal bridge building component is disclosed. The low thermal bridge building component includes at least two flanges and a web joining the at least two flanges and maintaining the outer surfaces of the at least two flanges in a roughly parallel configuration. The web has an R-value between 12 and 54 and comprises a perforation.
In another embodiment, a low thermal bridge wall component is disclosed. The low thermal bridge wall component includes at least two flanges and a web joining the at least two flanges and maintaining the at least two flanges in a roughly parallel configuration. The web has a single, integral web member. The web member is the only member that joins the at least two flanges.
The present disclosure will now be described more fully with reference to the accompanying drawings, which are intended to be read in conjunction with both this summary, the detailed description, and any preferred or particular embodiments specifically discussed or otherwise disclosed. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of illustration only so that this disclosure will be thorough, and fully convey the full scope of the disclosure to those skilled in the art.
In the following description, reference is made to the accompanying drawings that form a part thereof, and in which is shown by way of illustration specific exemplary embodiments in which the embodiments of the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that modifications to the various disclosed embodiments may be made, and other embodiments may be utilized, without departing from the spirit and scope of the disclosure. The following detailed description is, therefore, not to be taken in a limiting sense.
One method of reducing energy usage in a building is to reduce conductive heat loss from thermal bridging through the exterior wall structure of the building. Thermal bridging may be reduced through the use of construction materials having relatively high thermal resistance, by reducing the cross-sectional area of wall structures, or through a combination of both. In the context of this disclosure, a cross-sectional area is defined as the intersection of the building component or element in question with a plane that is parallel to a wall or similar construction into which the building component or element may be integrated. As such, within the context of this disclosure, a cross-sectional area may typically be roughly perpendicular to a direction of heat transfer conduction through the construction component. One objective of the low thermal bridge building components is to reduce thermal bridging and resulting energy loss through these components in buildings. The low thermal bridge components disclosed herein may significantly reduce conductive heat transfer and thus reduce the energy required to heat or cool a residential, commercial, or other type of building.
Low thermal bridge studs, plates, and other building components disclosed herein may allow builders to use standard construction techniques. Construction time and procedures may be similar to conventional wall framing using standard construction techniques with dimensional lumber. Construction costs may also be similar to standard construction costs using dimensional lumber. Walls constructed using building components and methods disclosed herein can be thick and thus allow for thick insulation having high R-values, while still being light weight and using less wood for framing compared to conventional techniques.
As shown in
A standard 8 foot long dimensional lumber stud has a cross-sectional area of approximately 144 square inches (1.5 inches×96 inches). The low thermal bridge building component 1 has a much smaller cross-sectional area than a traditional standard dimensional lumber stud. In the embodiment depicted in
Embodiments of the present disclosure having less material volume than similarly-sized traditional dimensional lumber may, as a result, weigh less than similarly-sized traditional dimensional lumber. Table 1 illustrates typical weights for various dimensional lumber beams.
In comparison, similarly-sized embodiments of the present disclosure may weigh substantially less than typical dimensional lumber beams. Table 2 depicts measured weights for building components according to the present disclosure.
The conductive heat transfer through a wall stud is directly proportional to the cross-sectional area of the stud. If the cross-sectional area is reduced, the heat transfer may be reduced proportionally. Therefore, the embodiment depicted in
In a typical installation, building component 1 may be installed within a wall with each flange 3 abutted and affixed to a wall surface. For example, one flange 3 may be affixed to drywall panels forming an interior wall. That flange 3 would accordingly comprise an inner-facing flange 3 and the flange 3 surface which abuts the drywall panels may comprise a peripheral inner-facing surface. Likewise, the other flange 3 may be affixed to exterior wall panels at the peripheral outer-facing surface of that flange 3. However, it is to be understood that the peripheral inner-facing surface and the peripheral outer-facing surface of building component 1 might not necessarily be affixed to an interior or exterior wall, respectively.
In embodiments of the present disclosure, the webs 2 and flanges 5 may be constructed using dimensional lumber or engineered materials such as oriented strand board (OSB), plywood, laminated veneer lumber (LVL), laminated strand lumber (LSL), rim-board, glued laminated lumber (glulam), like materials, or combinations thereof. Use of engineered materials may provide increased dimensional stability in comparison to dimensional lumber. Dimensional stability may also be improved in components where dimensional lumber is used because the movement of one flange 3 can be counteracted by the other due to the webs 2 that connect the flanges 3. Alternatively, the flanges 3, webs 2, or both may be manufactured from other materials such as aluminum, steel, or plastic or plastic composites. The web may also be made of honeycomb, rigid foam insulation, or other insulating material to reduce the thermal bridge between the flanges 3. As will be understood by one of ordinary skill in the art having the benefit of this disclosure, other materials of manufacture may be suitable for the web 2 and flanges 3. Such materials fall under the scope of this disclosure.
Dimensional lumber used for framing buildings may be prone to cupping, bowing, twisting, and crowning. This dimensional instability may cause the dimensional lumber to be more difficult to frame for doors and windows because it may be difficult to keep the door and window rough openings square, level, plumb, and flat for window mounting and door hanging. Embodiments of low thermal bridge building components according to the present disclosure may be more dimensionally stable, which could allow for easier and better installation of doors and windows. This advantage may be especially pronounced where engineered wood products are used for the flanges 3 of the building components. The use of flanges 3 that are wider than dimensional lumber may also provide a wider nailing surface, which may result in fewer nail misses during construction.
Webs 2 may be cut from dimensional lumber or from the types of engineered wood products mentioned above. For embodiments that comprise holes 5 in the webs 2, such holes can be drilled, punched, or made using other methods. These holes 5 may further reduce the heat transfer through the web 2 by reducing the cross-sectional area of each web 2 without significant reduction of the strength of the web 2 or the web-to-flange joint. Web 2 thickness and width can be selected to meet the structural requirements of the assembly and the insulation requirements of the building's walls. The flanges 3 can be made from dimensional lumber or engineered wood products. The groove 9 can be cut using a dado blade on a table saw or other suitable milling technique. The cross-sectional dimensions of the flanges 3 are selected to meet structural and rigidity requirements of the assembly. For example, buildings that are constructed in areas with high snow loads may need larger flanges 3 to meet structural buckling requirements. The strength and/or rigidity of the flanges 3 may be based on their area moment of inertia. For a rectangular lateral cross-section of a flange member 3, the mathematical formula for the area moment of inertia is:
where:
I is the moment of inertia of the flange member 3;
b is the side-to-side thickness of the flange member 3; and
d is the depth of the flange member 3 in the direction that a force is applied.
This equation shows that a small increase in the depth can greatly increase the strength and rigidity of the flange 3 when it is subjected to bending or column loading because the depth is cubed in the equation. The flange 3 dimensions may also be selected to allow for fastening of sheet material (e.g. OSB or the like) and/or siding to the outside flange 3 and materials such as sheetrock or wood products to the inside flange 3. Use of wide flanges 3 may reduce the chance for nails or screws to miss the studs during attachment of sheeting products.
Building component embodiments according to the present disclosure may be constructed by applying glue to grooves 9 and then forcing the webs 2 and flanges 3 together using clamps or other suitable means, thereby forming joints 4 between web 2 and flanges 3. The width of groove 9 may be selected to allow for a forced fit with the webs 2 so that the assembly retains its integrity after the clamping force is removed. Assembly fixtures may be used during assembly to maintain the dimensional integrity of the low thermal bridge building component 1 (in other words, maintaining the component flat, straight, etc.). In alternative embodiments, the webs 2 are nailed and/or stapled to the flanges 3. In addition or alternatively, the webs 2 are placed in mortised holes that are a partial or full depth of the flanges 3.
As an example, if 2 inch diameter holes 13 are spaced to leave ½ inch of web 12 material between the holes, the resulting cross-sectional area of the assembly is approximately 10 square inches for an 8 foot long stud. Accordingly, such a building component has a cross-sectional area that is approximately 6.94% of a standard dimensional lumber stud and thus will have only approximately 6.94% of the conductive heat transfer of a dimensional lumber stud. Various hole 13 sizes and/or spacing may achieve different results.
Referring to
Embodiments comprising a web 25 that is made of honeycomb or rigid foam may exhibit superior thermal insulating properties relative to traditional building components. For example, one embodiment comprises two wood flanges, each flange having a thickness of approximately 1.5 inches, and a rigid polystyrene web having a thickness of 2.5 inches. A polystyrene web that is 2.5 inches thick may have an R-value of approximately 12.5, using a commonly-accepted R-value of polystyrene of 5/inch. The flanges may have a cumulative R-value of approximately 3.75, using a commonly-accepted R-value of wood of 1.25/inch. Thus, such a building component embodiment may have a total R-value of approximately 16.25. As another example, an embodiment comprises two wood flanges, each flange having a thickness of approximately 1.5 inches, and a rigid polyisocyanurate web having a thickness of 8.25 inches. A polyisocyanurate web that is 8.25 inches thick may have an R-value of approximately 53.63, using a commonly-accepted R-value of polyisocyanurate of 6.5/inch. The flanges may have a cumulative R-value of approximately 3.75. Thus, such a building component embodiment may have a total R-value of approximately 57.38. By varying the thickness of the web and/or flanges or by varying the materials of the web and/or flanges, components having other R-values are conceivable.
An alternate fabrication approach is to spray foam insulation between two flanges 24 that are held flat and parallel by fixtures. This approach may be accomplished without glue or fasteners, as the spray foam may adhere directly to the flanges 24. The continuous web 25 may allow the building component 23 to be cut to any length without compromising the structural integrity of the assembly. Long component 23 lengths may be achieved using embodiments of building component 23.
In operation, embodiments of building components of the present disclosure may be used as studs, plates, headers, or like components in wall assemblies in construction. Building components disclosed herein may take the place of traditional dimensional lumber or engineered wood studs, plates, and/or headers. Referring now to
As one of ordinary skill having the benefit of this disclosure would understand, embodiments presented herein may provide certain useful advantages over traditional building components and techniques. Such benefits may include reduced conductive heat transfer through building walls and thus reduced energy consumption. Another benefit may include a greater degree of design selection flexibility, including the ability to selectively vary wall thickness by selectively altering the size of the webs. Additionally, a thicker wall may permit an increased amount of insulation material to be placed therein. Walls constructed with embodiments of the present disclosure may be lighter in weight than similar sized walls constructed with traditional studs and other components. Lighter walls may be less costly to transport to a building site.
Walls constructed with embodiments of the present disclosure may also use less lumber than similar-sized walls that are constructed using dimensional lumber or other traditional building components. Low thermal-bridging building components of the present disclosure can simplify the construction of highly-insulated buildings and thereby result in reduced construction and material costs.
Although the present disclosure is described in terms of certain preferred embodiments, other embodiments will be apparent to those of ordinary skill in the art, given the benefit of this disclosure, including embodiments that do not provide all of the benefits and features set forth herein, which are also within the scope of this disclosure. It is to be understood that other embodiments may be utilized, without departing from the spirit and scope of the present disclosure.
This application is a continuation-in-part of U.S. patent application Ser. No. 13/778,113, filed Feb. 26, 2013, and titled “LOW THERMAL BRIDGE BUILDING COMPONENTS,” which claims priority to U.S. Provisional Patent Application Ser. No. 61/603,945, filed on Feb. 28, 2012, and titled “LOW THERMAL BRIDGE STUDS, PLATES, AND HEADERS.” This application claims priority to all such previous applications, and the entire contents of such applications are hereby incorporated herein by reference.
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| Number | Date | Country | |
|---|---|---|---|
| 61603945 | Feb 2012 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13778113 | Feb 2013 | US |
| Child | 14104734 | US |
