KR20120099045A - Article for controlling attic moisture - Google Patents

Abstract

To improve the energy efficiency of buildings and to achieve the building's energy efficiency, which is typically achieved by providing an air gap between the breathable membrane and the roof deck by installing an attic tray on the roof rafters to conserve energy passing from the living space into the building attic and out of the building top. Attic trays are disclosed that are made of breathable membranes used to control moisture in attic.

Description

ARTICLE FOR CONTROLLING ATTIC MOISTURE}

The present invention relates to improved building building materials for controlling attic moisture and improving the energy efficiency of buildings.

Some types of buildings have a space known as Attic located beneath the roof structure and above a useful living space. In this type of building it is common to use rafters and decking within the attic space. It is typical to use airflow to control the moisture level in the attic by venting air from the building's eaves to the ridge vent at the top of the roof. Air flows by convection from an empty space along the eaves (between the walls of the building and the bottom of the roofline) to an empty space along the ridge (s) at the top of the roof, such as a ridge vent. This flow of air removes moisture from the attic before moisture can accumulate in the attic. Moisture generally enters the vapor form from the living space into the attic. Moisture sources within the living space include human breathing, the use of bathtubs and showers, cooking, indoor plants, and the like.

Typically, 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 good moisture control within the attic, but it is not energy-efficient because the living space is not enclosed and energy from the climate-controlled living space leaks out of the building through the ridge vent with the air flow. .

Expandable foams have been used to insulate and seal the attic. Foam is sprayed under the roof decking and inside the roof rafters, or on the "floor" of the attic. This can effectively seal the attic, but this method does not prevent moisture from accumulating in the attic because the typical foam is not breathable and does not allow air to flow through the attic, which is therefore unacceptable for many climates. A common method of providing attic aeration is a vacuum molded plastic tray having a flange attached on the top edge of the rafters. The design of these products does not allow any change in the space between the rafters, which are formed from rigid materials such as plastic and cardboard which are not vapor permeable. E.I.Wilmington, Delaware, USA. Zatkulak's US Patent Publication No. 2006/0260265, assigned to EI DuPont de Nemours and Company (DuPont), uses a breathable membrane positioned across the top of the rafters to attract attic moisture. A method of controlling is disclosed. In order to securely place the membrane over the rafters, large pieces of the membrane must be handled by the people installing the material. This turned out to be cumbersome. Especially when trusses are used with their accompanying cross braces, it is difficult to attach the membranes to the underside of the rafters, because large pieces of the membranes are difficult to handle in the attic space.

It would be desirable to provide building materials and methods that provide good control of moisture within the attic with a safer and easier installation while eliminating the exchange of air between the living space and the attic.

The invention relates to first and second opposing edges and top and bottom opposing edges, and side supports adhesively attached to the first and second opposing edges, and top overlaps at the top edge—at least A portion coated with adhesive—, and an attic tray comprising a breathable membrane having a bottom overlap at the bottom edge.

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1 shows an assembled attic tray folded in for installation;
2A to 2C.
2A-2C are cross-sectional and side views of an installed attic tray;

Justice

The term "active air space" refers to an air space that allows air to move freely in and out of the air space in response to conditions affecting air flow, such as a thermal gradient.

The term "roof deck" is used interchangeably with the term "roof decking" and is a roofing material (eg, shingle) such as plywood or oriented strand board (OSB). ) Refers to the structural board installed in the upper part.

The term “eave” herein generally refers to the intersection between the roof and the wall of the building.

The term "ridge vent" herein generally refers to the space along their top edges between the different planes of the roof decking, typically protected by a cap.

The term "peripheral building wrap" as used herein refers to the use of a flexible sheet material to wrap an unfinished wall of a building, such as a weather-resistive barrier.

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

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 active flow of air entering the air space from the cornice and exiting the building from the roof ridge. As shown in FIG. 2A, the active air space 6 is the space between the attic tray 1 and the roof deck 10. The active air space removes water vapor as indicated by the arrows from the attic space to avoid moisture buildup in the timber of the rafters 12 and roof deck 10. 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 supports 200 attached to first and second opposing edges, which can be fastened to the rafters. The membrane is typically rectangular and can be shown and described as such herein, but is not limited by shape. In one embodiment, the membrane may be about 50.8 cm (20 inches) wide by 111.8 cm (44 inches) long to form an attic tray having a width for fitting the rafter openings with studs spaced 40.6 cm (16 inches) apart. have.

The side support 200 holds the breathable membrane in place and the main purpose of the support is to provide a reinforcement to the breathable membrane to allow the installer to handle the attic tray without flopping. The side supports can be constructed from rigid or semi-rigid materials, since some flexibility has been found to assist in positioning the attic trays. Some suitable materials are corrugated plastics, cardboard, plastics and wood, such as Coroplast® (available from Coroplast, Inc., Dallas, TX). Preferred material is corrugated plastic. There is no restriction on the size of the support, but it has been found that fragments measuring 7.0 cm (2.75 inches) wide by 111.8 cm (44 inches) long are suitable. The side support may optionally be provided with perforations 210 as shown in FIG. 1 to allow a portion of the side support to bend to form the flange 212. The flange will form a nailing surface for attaching the attic tray to the horizontal surface of the rafters. The large perforations form the attic trays in a manner that allows the side supports to bend inward or outward, as shown in FIGS. 2C and 2B, respectively, allowing installation from the bottom of the attic space or from the top of the roof above. Will be done.

Optionally, a dead folding reinforcement 400 as shown in FIG. 1 may be used to maintain the bent position of the side support. Any material having the ability to hold and hold a fold, known as a dead fold, without spring back can be used as the dead fold reinforcement. Suitable materials are metal wires, metal sheets, biaxially oriented polyester and HDPE sheets. Preferred dead fold reinforcements are made of metal wires. The dead fold reinforcement may run across the connections of the side supports to the transverse supports, across the perforations, or both. When metal wires are used for the dead fold reinforcement, an optional hook shape 400a as shown in FIG. 1 has been found to prevent the wires from running loose.

Optionally, to provide increased rigidity during installation and to prevent the breathable membrane from sagging after installation, a transverse support 300 as shown in FIG. 1 runs from the side support to the side support on the opposite edge along one edge. Can be provided to The transverse support may be about 5.1 cm (2 inches) wide by 36.8 cm (14.5 inches) long.

The attic tray of the present invention is formed by adhesively attaching a support to a breathable membrane, as shown in FIG. Any adhesive known to be bonded to the nonwoven can be used, such as hot melt adhesives and acrylic adhesives. Preferred adhesives are hot melt adhesives, such as the Duro-Tak 4233 hot melt adhesive supplied by Nacan Products Limited, Brampton, Ontario, Canada. The side support and the optional transverse support may be a single structure that is cut from a single piece of material or assembled from several pieces. Perforations to allow bending are disposed with optional reinforcement to hold the fold at the fold between the side support and the transverse support when the attic tray is formed as a unitary structure. The transverse support abuts the side support when formed from the pieces to be assembled. Dead fold reinforcement is preferred for the connection between the side support and the transverse support when assembled from the pieces.

In order for each attic tray to form a continuous breathable membrane with the other attic trays installed in the rafter opening and the wall below, a sealing means for connecting them is required. It has been found that a length of breathable membrane extending from each end of a section of the breathable membrane with a frame by the support provides a suitable means for superimposing one tray on another tray. 1 shows an assembled attic tray having a lower overlap 130 at the bottom of the membrane and an upper overlap 120 at the top of the membrane. The upper overlap includes at least a portion coated with adhesive 110, which may be covered with 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 in the rafters opening, fastening it in place and sealing the connection with any attic tray or adjacent wall surface. The attic trays are arranged as is typically done in a roofing process by completing a predetermined course along one eave of the building structure and then proceeding to install subsequent attic trays in rows above. The upper attic tray, if present, is sealed against the lower attic tray by peeling off the release paper to expose the adhesive strip and pressing the lower overlap 130 of the upper attic tray onto the upper overlap 120 of the lower attic tray. In a situation where no second attic tray touches the end of the first attic tray, the overlap is sealed against the surrounding building wrap. The roof decking is then constructed using typical roofing materials such as sheathing and asphalt shingles. Applying the cladding after each course of the attic trays has been found to be particularly useful. Subsequent courses of the attic trays can be safely installed by the installer by using the cladding as a work platform. The attic tray can also be fastened to the bottom of the rafters. Mounting the attic tray at the bottom of the rafters allows the operator to work from the attic and avoids any fall hazards inherent in roof construction.

In another embodiment of the present invention, the attic tray is formed into a roll. The rolls are nailed and sealed at the top of the roof and spread to the cornice, forming a continuous attic tray.

The present invention utilizes the breathable membrane 100. The breathable membrane may be any vapor permeable material, preferably having a moisture vapor transmission rate of about 20 US perm or greater when tested according to ASTM E96 Method A. The breathable membrane allows moisture to diffuse through the membrane from the attic space into the active air space, where the moisture is transported outward through the ridge vent by the flowing air. The chimney effect formed by the active air space has been found to improve 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 59 N / cm (34 lb / in) in the machine direction and about 52 N / cm (30 lb / in) in the width direction. Preferably, the membrane is oven dried at 48.9 ° C. (120 ° F.) for 3 hours, immersed in water at room temperature for 3 hours, and air for 18 hours at room temperature (22.8 ° C. (73 ° F.). The strength is not lost after exposure to 25 cycles of accelerated aging consisting of drying. Also preferably, the membrane is exposed to UV radiation for 210 hours (10 hours per day for 21 days) at an irradiance of 5.0 watts per square meter at a wavelength of 315-400 nm, without any loss of intensity. There are no signs of damage, where the membrane is kept at a distance of 1 meter from the UV source at a membrane temperature of 60 ° C. (140 ° F.).

One example of a suitable breathable membrane is a two-layer composite sheet having Tyvek® high density polyethylene (available from DuPont) as an inner layer and a durable spunbond polypropylene sheet as an outer layer. Composite sheets can be made by joining two layers with an adhesive and placing them in a thermal calendering process. The temperature of the calendering process should be sufficient to melt the adhesive, and the nip pressure presses the molten adhesive around the two layers of fibers to mechanically fix the two layers together and high peel strength of the composite sheet. Should be sufficient to ensure that

Other examples of materials suitable for use as the breathable membrane of the present invention can be found, for example, under the tradename Roofshield® (A. Proctor Group, Ltd., UK). Spunbond polyolefin nonwoven sheets, including three-layer spunbonded polypropylene fabrics such as roof underlays available. Other materials suitable for use as breathable membranes include nonwoven sheets comprising sheath-core bicomponent melt spun fibers such as described in US Pat. No. 5,885,909, which is incorporated herein by reference; And multiple layers of cis-core bicomponent melt spun fibers and parallel bicomponent meltblown fibers, such as those described in US Pat. Nos. 6,548,431, 6,797,655, and 6,831,025, which are incorporated herein by reference. It is a composite sheet. For example, the bicomponent melt spun fibers may have a sheath of polyethylene and a core of polyester. When a composite sheet comprising multiple layers is used, the bicomponent meltblown fibers have a polyethylene component and a polyester component and can be arranged in parallel along their length. Typically, parallel and sheath / core bicomponent fibers separate the layers in a multilayer arrangement.

Description of typical installation of the tray

1. The flat attic tray was bent along the wire-reinforcing bond of the side support with the transverse support to form the tray.

2. The side supports were folded along the perforations to form flanges.

3. The attic tray was placed in the roof rafters opening starting at one end of the cornice.

4. Staples were driven through the flanges to the top surface of the roof rafters.

5. Staples were driven through the side supports into the inner walls of each roof rafters.

6. Bottom overlap was wrapped around the cornice and superimposed on wall housewrap and sealed with Tyvek tape.

7. Repeat steps 1 to 6 for all the rafter spaces in rows along the eaves.

8. The roof deck plywood was installed across the attic trays using standard nailing specifications.

9. Using plywood decking as the working platform, additional attic trays were installed over the row of installed attic trays previously installed along the cornice.

10. The release tape was removed from the top overlap of the previously installed attic tray and sealed to the bottom overlap of the attic tray installed thereon.

11. Repeat steps 8 to 10 for all remaining rafter openings.

Claims (9)

As an attic tray,
First and second opposing edges and top and bottom opposing edges, and side supports adhesively attached to the first and second opposing edges, and an upper overlap at the top edge—at least in part an adhesive Coated with-an attic tray comprising a breathable membrane having a bottom overlap at the bottom edge. The attic tray of claim 1 comprising at least one transverse support extending from the side support on the first edge to the side support on the second edge and adhesively attached to the breathable membrane. The attic tray of claim 2 comprising perforations in the side supports. The attic tray of claim 3 comprising a dead fold reinforcement across the perforations. The attic tray of claim 4, wherein the breathable membrane is a three layer spunbonded polypropylene fabric. The attic tray of claim 4, wherein the breathable membrane is a two-layered composite sheet of flashspun 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 of claim 4 wherein the breathable membrane is a nonwoven sheet of sheath-core bicomponent melt spun fibers, wherein the sheath is polyethylene and the core is polyester. 5. The breathable membrane of claim 4 wherein the breathable membrane is a composite of a layer of sheath / core bicomponent melt spun fibers and a layer of parallel bicomponent meltblown fibers, wherein the bicomponent is polyethylene and polyester and the sheath / core 2 Attic tray in which the sheath is polyethylene and the core is polyester.

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