JP2013508575A - Articles and methods for controlling moisture - Google Patents

Abstract

Attic trays made from breathable membranes, where the trays are installed above the roof rafters, thereby providing the presence of a gap between the breathable membranes and the roof deck, thereby allowing the attic from the normal living space An attic tray used to control moisture in the attic of the building and improve the energy efficiency of the building, achieved by allowing energy to enter and exit from the top of the building.

Description

  The present invention relates to an improved building material that controls attic moisture and increases building energy efficiency.

  Some types of buildings have a space known as the attic located directly below the roof structure and above the useful living space. In this type of building, it is common to use rafters and decking in the attic space. It is common to control the moisture level in the attic by using airflow to ventilate air from the building eaves to the ridge vent at the highest point of the roof. Air can flow by convection from an open space along the eave (between the building wall and the bottom of the roof contour) to an open space along the ridge at the top of the roof, for example, a ridge vent. . This air flow removes moisture from the attic before it can accumulate in the attic. Moisture typically enters in the form of steam from the living space. Sources of moisture in the living space include human breathing, use of bathtubs and showers, cooking, and indoor potted plants.

  Usually, the attic is open to the flow of air from the living space and from the outside of the building surrounding the eaves. This allows for excellent moisture control in the attic, but the living space is not sealed, and energy from the environmentally controlled living space leaks out of the building vent with the airflow to the outside of the building. Inefficient.

  Intumescent foams have been used to insulate and seal the attic. The foam is sprayed under the roof decking and inside the roof rafters or on the attic “floor”. This effectively seals the attic, but this method prevents moisture from accumulating in the attic because normal foam is not breathable and does not allow air to flow through the attic. Therefore, this is not acceptable for many climates. A common method of enabling attic ventilation is a vacuum molded plastic tray with a flange attached to the top edge of the rafter. These product designs do not take into account any deformation of the space between the rafters, which are formed from rigid materials such as plastic and cardboard that are not vapor permeable. E. I. US Patent Application Publication No. 2006/0260265 to Zatkulak, assigned to DuPont de Nemours and Company, Wilmington DE (DuPont), controls attic moisture using a breathable membrane placed on top of a rafter. A method is disclosed. In order to ensure that the membrane is laid on the rafters, the person installing the material must handle the large membrane. This proved to be cumbersome. It is difficult to attach the membrane to the underside of the rafters, especially when trusses are used with their accompanying cross braces, because it is difficult to handle large membranes in the attic space.

  It would be desirable to provide a building material and method that eliminates the exchange of air between the living space and the attic while allowing for safer and easier installation and better control of moisture in the attic.

  The present invention is a breathable membrane having a first edge and a second edge facing each other, and a top edge and a bottom edge facing each other, and a side support portion is adhesively attached to the first edge and the second edge facing each other An attic tray comprising an air permeable membrane, an upper overlap upper portion and at a lower overlap lower portion, at least partially coated with an adhesive.

FIG. 3 is an assembled attic tray folded for installation. A side view of the installed attic tray is shown. Sectional drawing of the installed attic tray is shown. Sectional drawing of the installed attic tray is shown.

Definitions The term “active air space” refers to an air space in which air can move freely in and out depending on conditions affecting air flow, eg temperature gradients.

  The term “roof deck” is used synonymously with the term “roof decking” and a structure in which a roofing material (eg roofboard) is installed, such as plywood or oriented strand board (OSB). Refers to the board.

  As used herein, the term “eave” generally refers to the intersection between a roof and a building wall.

  As used herein, the term “ridge vent” generally refers to the space along their top edge between different planes of roof decking, usually protected with a cap.

  As used herein, the term “peripheral building wrap” refers to the use of a flexible sheet material that covers unfinished walls of a building, such as a weather resistant barrier.

  The term “rafter” is used herein to refer to separate structural load-bearing elements that form the upper part of a building attic (commonly referred to as joists, beams, trusses).

  The term “rafter opening” is used herein to refer to the space between adjacent rafters.

  The present invention provides an attic tray to form an active air space directly under the roof deck for the effective flow of air from the eaves into the air space and out of the roof ridge. As shown in FIG. 2A, the active air space 6 is a space between the attic tray 1 and the roof deck 10. The active air space removes water vapor from the attic space as indicated by the arrows so that moisture does not accumulate on the rafters 12 and the roof deck 10 wood. The present invention also seals the attic, thereby minimizing air exchange between the living space and the attic and providing significant energy savings.

  As shown in FIG. 1, the attic tray of the present invention includes a breathable membrane 100 having side support portions 200 that can be fastened to rafters attached to opposing first and second edges. Yes. The membrane is generally rectangular and can be shown and described as such herein, but is not limited by shape. In one embodiment, the membrane can be about 20 inches wide by about 44 inches long to form an attic tray that is wide enough to fit a rafter opening with 16 inch core posts.

  The side support 200 holds the breathable membrane in place and the main purpose of this support is to provide reinforcement to the breathable membrane so that the installer can handle it without turning the attic tray over. Is to do. The side supports can be constructed from rigid or semi-rigid materials because some flexibility is believed to help position the attic tray. Some suitable materials are Corroplast® (available from Coroplast, Inc, Dallas TX), cardboard plastic, such as cardboard, plastic and wood. A preferred material is corrugated plastic. Although the size of the support is not limited, it has been found that a 2.75 inch wide by 44 inch long piece is suitable. A flange 212 can be formed by bending a part of the side support part by arbitrarily providing a perforation as shown in FIG. 1 in the side support part. The flange forms a nailing surface for attaching the attic tray to the horizontal surface of the rafter. Large perforations allow the side supports to bend inward or outward, thereby allowing installation from the lower attic space or from the upper roof as shown in FIGS. 2C and 2B, respectively. Attic trays can be formed.

  Optionally, the bent position of the side support can be maintained using a dead fold reinforcement 400 as shown in FIG. Any material known as deadfold, capable of forming and holding a fold without splashing, can be used as the deadfold reinforcement. Suitable materials are metal wires, metal sheets, biaxially oriented polyester and HDPE sheets. A preferred deadfold reinforcement consists of a metal wire. The deadfold reinforcement can extend across the junction of the lateral support to the transverse support, across the perforation, or both. It has been found that when a metal wire is used for the deadfold reinforcement, an optional hook shape 400a as shown in FIG. 1 prevents the wire from loosening.

  Optionally, to increase stiffness during installation and to extend from the side support along one edge to the side support on the opposite edge so that the breathable membrane does not sag after installation. A transverse support 300 as shown in FIG. The transverse support can be about 2 inches wide by about 14.5 inches long.

  As shown in FIG. 1, the attic tray of the present invention is formed by attaching and attaching a support portion to a breathable membrane. Any adhesive known to adhere to nonwovens may be used, such as hot melt adhesives and acrylic adhesives. A preferred adhesive is a hot melt adhesive, such as the Duro-Tak 4233 hot melt adhesive provided by Nacan Products Limited, Brampton, Ontario, Canada. The side support and optional transverse support may be a unitary structure cut from a piece of material or may be constructed from various pieces. When the attic tray is formed as a unitary structure, the perforations that allow bending are located in the crease between the side support and the transverse support and there is any reinforcement to maintain the crease. When formed from a built piece, the transverse support is abutted against the side support. When constructed from multiple pieces, a deadfold reinforcement is preferred for the joint between the side support and the transverse support.

  In order to allow each attic tray to form a continuous breathable membrane and other attic trays to be installed in the rafter opening and the underlying wall, sealing means connecting them is required. is there. A length of breathable membrane extending from each end of the portion of the breathable membrane that is framed by the support provides a suitable means of stacking one tray on top of another. I understood. FIG. 1 shows an assembled attic tray with a lower overlap 130 at the bottom of the membrane and an upper overlap 120 at the top of the membrane. The top overlap incorporates at least a portion that is coated with an adhesive 110 that can be covered by a release paper (not shown). Any adhesive known to adhere to the nonwoven material can be used.

  The attic tray is installed by placing the folded tray in place at the rafter opening and fastening it in place to seal the junction with any attic tray or adjacent wall. The attic tray is placed by completing a course along one eave of the building structure, followed by the subsequent installation of the attic tray, as is usually done in the roofing process. The The upper attic tray, if present, peels the release paper to expose the adhesive strip, and presses the upper attic tray lower overlap 130 onto the lower attic tray upper overlap 120. Of the attic tray is sealed to the lower attic tray. In situations where the second attic tray is not in contact with the end of the first attic tray, the overlap is sealed to the surrounding building wrapping. And roof decking is comprised using normal roof materials, such as a covering material and an asphalt roof board. It has been found particularly useful to apply the coating material after each layer of the attic tray has been installed. Subsequent layers of the attic tray can be safely installed by the installer using the coating material as a working scaffold. It is also possible to fasten the attic tray to the bottom of the rafters. By attaching the attic tray to the bottom of the rafters, the operator can work from the attic and avoid any fall hazard inherent in roofing.

  In another embodiment of the invention, the attic tray is formed into a roll. The roll is nail-fixed and sealed at the highest point of the roof and pulled out to the eaves to form a continuous attic tray.

The present invention utilizes a breathable membrane 100. The breathable membrane can be any vapor permeable material, preferably having a water vapor transmission rate of at least about 20 US perm tested according to ASTM E96 Method A. The breathable membrane allows moisture to diffuse through it from the attic space into the active air space, where the moisture is conveyed out of the building vent by the flowing air. It can be seen that the chimney effect formed by the active air space facilitates the removal of moisture from the attic space. Preferably, the breathable membrane is durable and UV resistant. Preferred membranes have a tensile strength (according to ASTM test method D828) of at least about 34 lb / in (59 N / cm) in the length direction and about 30 lb / in (52 N / cm) in the width direction. Preferably, the membrane is subjected to a 25 cycle accelerated aging test consisting of oven drying at 120 ° F. for 3 hours, immersion in water for 3 hours at room temperature, and air drying for 18 hours at room temperature (73 ° F.). After losing strength. Also preferably, the film has been exposed to UV radiation for 210 hours (10 hours / day for 21 days) at a irradiance of 5.0 watts / m ² at a wavelength of 315-400 nm, where the film is (Held at a distance of 1 meter from the UV source at a film temperature of 140 ° F.) does not lose strength and does not show any visual evidence of damage.

  An example of a suitable breathable membrane is a two-layer composite sheet comprising Tyvek® high density polyethylene (available from DuPont) as the inner layer and a durable spunbond polypropylene sheet as the outer layer. Composite sheets can be made by joining two layers with an adhesive and subjecting them to a thermal calendar process. The temperature of the calendar process should be sufficient to melt the adhesive, and the nip pressure is a composite where the melt adhesive around the fibers of the two layers mechanically locks the two layers together. It should be sufficient to ensure a high peel strength of the sheet.

  Other examples of materials suitable for use as breathable membranes in the present invention include, for example, roof coverings sold under the trade name Roofshield® (available from A. Proctor Group, LTd., UK) A spunbond polyolefin nonwoven sheet comprising a three-layer spunbond polypropylene fabric. Other materials suitable for use as breathable membranes include a sheath-and-sheath such as those described in US Pat. No. 5,885,909, incorporated herein by reference. -Core) non-woven sheets comprising composite melt spun fibers and US Pat. Nos. 6,548,431, 6,797,655 and 6,831 which are hereby incorporated by reference. No. 025, a composite sheet comprising a plurality of layers of core-sheath type composite melt spun fibers and side-by-side type composite melt blown fibers. For example, a composite melt spun fiber can have a polyethylene sheath and a polyester core. When a composite sheet comprising multiple layers is used, the composite meltblown fiber can have a polyethylene component and a polyester component and can be arranged in parallel along its length. Usually, side-by-side conjugate fibers and core-sheath conjugate fibers separate layers in a multilayer configuration.

Explanation of standard installation of trays A flat attic tray was bent along the wire reinforced joint with the transverse support of the side support to form the tray.
2. The side support was bent along the perforations to form a flange.
3. An attic tray was placed at the roof rafter opening starting at one end of the eaves.
4). Staples were driven into the top surface of the roof rafters through the flange.
5. Staples were driven into the inner wall of each roof rafter via the side support.
6). The bottom overlap was wrapped around the eaves, partially over the wall house wrap and sealed with Tyvek tape.
7). Steps 1-6 were repeated for all rafter spaces arranged along the eaves.
8). A roof deck plywood was placed on the attic tray using standard nailing procedures.
9. Using plywood decking as a working scaffold, an additional attic tray was installed above the installed attic tray along the eaves.
10. The release tape was removed from the upper overlap portion of the attic tray previously installed and sealed to the bottom overlap portion of the attic tray installed above it.
11. Steps 8-10 were repeated for all remaining rafter openings.

Claims (9)

  A breathable membrane having opposing first and second edges and opposing top and bottom edges; a side support adhesively attached to the opposing first and second edges; and at least a portion An attic tray comprising an upper overlap portion at the upper edge and a lower overlap portion at the bottom edge, wherein the upper overlap portion is coated with an adhesive.   The one or more transverse supports extending from the lateral support of the first edge to the lateral support of the second edge and adhesively attached to the breathable membrane. The attic tray according to 1.   The attic tray of claim 2, wherein the side support is provided with perforations.   The attic tray of claim 3 comprising a deadfold reinforcement that traverses the perforations.   The attic tray of claim 4, wherein the breathable membrane is a three-layer spunbond polypropylene fabric.   The attic tray of claim 4, wherein the breathable membrane is a two-layer composite sheet of flash spun high density polyethylene sheet and spunbond polypropylene sheet.   The attic tray of claim 4, wherein the breathable membrane is a flashspun high density polyethylene sheet.   The attic tray according to claim 4, wherein the breathable membrane is a nonwoven sheet of core-sheath type composite melt spun fiber, the sheath is polyethylene, and the core is polyester.   The breathable membrane is a composite of a core-sheath type composite melt-spun fiber layer and a side-by-side type composite melt-blown fiber layer, and each composite is polyethylene and polyester. In the core-sheath type composite fiber, the sheath The attic tray according to claim 4, wherein is a polyethylene and the core is polyester.

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