US20080120935A1

US20080120935A1 - Vapor retarder fastening strip

Info

Publication number: US20080120935A1
Application number: US11/461,206
Authority: US
Inventors: Michael J. Lembo
Original assignee: Certainteed LLC
Current assignee: Certainteed LLC
Priority date: 2006-07-31
Filing date: 2006-07-31
Publication date: 2008-05-29

Abstract

An article for use in securing a vapor retarder to a structure includes a support member having first and second major surfaces, the first major surface oriented for receiving fasteners for fastening the member and vapor retarder to the structure and a gasket disposed on the second major surface.

Description

FIELD OF THE INVENTION

The present invention relates to building structures and more particularly to methods and systems for attaching vapor retarders to building structures.

BACKGROUND OF THE INVENTION

Moisture problems in walls have been attributed to water vapor diffusion and air leakage. Control of air movement and water vapor diffusion, therefore, is a major factor in building performance, as measured by how well a building functions during its lifespan. Depending on local climate, air leakage and water vapor diffusion through walls can result in excessive efflorescence, spalling of masonry, frozen pipes, condensation and ice buildup in cavities, wet and dysfunctional insulation, mold growth as well as rain penetration, high energy costs and poor control of the building environment.
Building designs often rely on the use of vapor barriers or retarders, such as polyethylene film, to control water vapor movement in the building envelope. The vapor barrier retards the diffusion of water through the assembly of materials in a wall. The rate at which water vapor migrates or diffuses through a material depends on two factors: the difference between the water vapor pressure in the air inside the building and that in the outside air, and the resistance that materials present to the migration of water by diffusion. A vapor barrier is a material that offers a higher resistance to the diffusion of water vapor than most other materials. Polyethylene film of sufficient thickness is the material most commonly used for this purpose; however, other materials such as aluminum foil, some paint products, some insulation mastic adhesives and some mastic coatings have been used as vapor barriers. Smart or adaptive vapor barriers—barriers that change permeance dependent on the humidity of the surrounding area—are also utilized. The moisture diffusion control property of a material is its water vapor permeance.
For the vapor barrier to control condensation resulting from vapor diffusion, it must be placed on or near the warm side of the insulation, which is normally the high vapor pressure side. Water vapor diffusion is one of the mechanisms by which water can be transported into a wall or roof cavity. The provision of a vapor barrier within the wall or roof assembly satisfies only part of the requirement of controlling moisture entry into building enclosures. The other significant mechanism is air leakage. Both mechanisms may, however, operate at the same time.
As mentioned, a vapor barrier is usually placed on the warm side of the insulation. It may also be positioned part way into the insulation batt, for satisfactory performance, it should be no further in than the point at which the temperature of the inside air drops to its dew point. While it is preferable that the air barrier system be placed on the warm side of an insulated assembly, it is not an essential requirement as it is with the vapor barrier. The position of the air barrier in a wall or roof is more a matter of suitable construction practice and the type of materials to be used.
Vapor barriers are typically installed over insulation batts placed in the cavities between wall studs. The vapor barrier sheets are secured to the studs with tacks, nails or staples, which puncture the membrane. These punctures can have a deleterious affect on the integrity of the vapor barrier.
Still further, the preferred method of installing drywall over the insulation is to at least partially attach the drywall to the wall studs with an adhesive. The adhesive holds the drywall in place while the installer secures the drywall to the studs with nails, staples or other fasteners. Most vapor barrier sheets will not accept the adhesive used to hold the drywall in place. This complicates the installation process as the drywall must be secured by hand until a sufficient number of fasteners are driven into the wall studs.

SUMMARY OF THE INVENTION

An article for use in securing a vapor retarder to a structure is provided. The article includes a support member having first and second major surfaces, the first major surface oriented for receiving fasteners for fastening the member and vapor retarder to the structure and a gasket disposed on the second major surface.
The article helps to preserve the integrity of the vapor barrier by sealing around punctures formed in the retarder layer. Still further, the fastening strip facilitates use of vapor retarder products with adhesive drywall applications. In embodiments, the fastening strip provides a much improved surface (vis a vis the vapor barrier) for receiving adhesive, either pre-applied or applied during installation, for mating with installed drywall. Still further, the fastening strip can be used as a shim for shimming up studs for providing a flat surface for receiving the drywall.
A wall structure is also provided. The wall structure comprises a plurality of structural supports having an insulation material disposed therebetween. At least one vapor retarder sheet is disposed over the structural supports and between the insulation material and an interior facing surface of the wall structure. The at least one fastening article includes a support member having first and second major surfaces, and a gasket disposed on the second major surface, the fastening article disposed over at least one of the structural supports with the gasket disposed on the vapor retarder. At least one fastener is disposed through the fastening article and the vapor retarder into the structural supports for securing the vapor retarder and fastening article.
A method is also provided, including the following steps: (a) installing a vapor retarder in a wall, floor or ceiling of a building, the vapor retarder being installed across a cavity defined between at least two structural supports; (b) providing at least one fastening article comprising a support member having first and second major surfaces and a gasket disposed on the second major surface, the fastening article disposed over at least one of the structural supports with the gasket disposed on the vapor retarder; and (c) driving at least one fastener through the fastening article and the vapor retarder into the structural support for securing the vapor retarder and fastening article.
The above and other features of the present invention will be better understood from the following detailed description of the preferred embodiments of the invention that is provided in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate preferred embodiments of the invention, as well as other information pertinent to the disclosure, in which:

FIG. 1 is a diagram of a first exemplary wall structure having a vapor barrier;

FIG. 2 is a diagram of a second exemplary wall structure having a vapor barrier;

FIG. 3 is a partial view showing a vapor retarder film fastening strip of the present invention installed over a vapor retarder;

FIG. 4A is a partial front view of the fastening strip with a release strip partially removed;

FIG. 4B is a partial rear view of the fastening strip showing a gasket thereon;

FIG. 4C is a cross-sectional view of the fastening strip taken along lines C-C of FIG. 4B;

FIG. 5A is a partial cross-sectional view of a wall structure having a first embodiment of an installed fastening strip;

FIG. 5B is a partial cross-sectional view of a wall structure having a second embodiment of an installed fastening strip.

DETAILED DESCRIPTION

This description of the exemplary embodiments 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, 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 and do not require that the apparatus be constructed or operated in a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” 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.
FIG. 1 shows a first configuration of a brick facade building wall structure 100 in which the fastening strip described herein can be used. The wall structure 100 includes the exterior ambient environment 102, brick 104, an air space 106, building paper 107, a 0.625 inch Oriented Strand Board (OSB) sheathing 108, a 3½″ thick fiber glass insulation batt 110 in a cavity formed between support structures (e.g., studs) (not shown), a vapor retarder layer 112, such as an adaptive vapor retarder film, drywall 114, latex paint 116, and the interior environment 118. Although the exemplary configuration is shown with a very short height, the exemplary structure can extend from the bottom to the top of an exterior wall.
FIG. 2 shows another exemplary configuration of a building wall structure 200 including, from left to right, an exterior ambient environment 202, a stucco finish 204, a “TYVEK®” spun bonded polyolefin air barrier house wrap 206 (sold by DuPont Corporation of Wilmington, Del.), an exterior sheathing 208, a 3½″ thick fiber glass batt 210, an adaptive vapor retarder film 212, an interior gypsum wallboard 214, an interior coating such as latex paint 216, and the building interior environment 218. These constructions are typical for low-rise commercial projects. Although the exemplary configuration is shown with a very short height, the exemplary structure can extend from the bottom to the top of an exterior wall.
FIG. 3 shows a fastening strip 10 of an embodiment of the present invention installed over a vapor barrier sheet 12 and affixed to a support structure, such as a wooden stud 14 using fasteners 16. FIG. 4A is a front plan view of an embodiment of the fastening strip 10 and FIG. 4B is a rear plan view thereof. FIG. 4C is a cross-sectional view of the fastening strip 10 taken along lines C-C. An exemplary strip has a width W of 1.5″ or less, and more preferably of about 1.0″. The length L of fastening strip 10 can vary as needed. In one embodiment, the length L can be about equal to the height of the wall, e.g., about 3-30′, more preferably between about 8-10′. Alternatively, fastening strip 16 can be provided in shorter lengths, such as between 2-3′ and multiple fastening strips can be installed over a single stud 14.
As best seen in the cross-section of FIG. 4C, an exemplary fastening strip 10 includes a support member, such as planar member 18, a gasket 20 and an optional layer of adhesive 22. Planar member 18 may comprise any low cost material adapted to receive adhesive layer 22, such as plastic, metal (e.g., steel, aluminum), wood, particle board or other composite material. Planar member 18 has a planar first major surface 17 and a second major surface 19. Second major surface 19 may also be planar or be formed with one or more grooves or recessed areas for receiving a gasket, described in more detail below. Planar member 18 provides a planar surface for application of adhesive 22 and for receiving fasteners 16. In exemplary embodiments, the planar member 18 has a thickness of less than or equal to about ½ inch, and more preferably less than or equal to about ¼ inch, and still more preferably less than or equal to about ⅛ inch and most preferably of about 1/16 inch.
A gasket member 20 is coupled to the second major surface 19 of the planar member 18, such as by an adhesive layer (not shown), melt bond, friction or form fit or other bond. The gasket 20 preferably comprises a compressible material that forms a vapor-tight seal around nail (or other fastener) punctures in the vapor retarder 12. In embodiments, the gasket member 20 comprises synthetic or natural rubber, silicone, polyurethane foam or an epoxy. The gasket preferably has a thickness of less than or equal to about ¼″, and more preferably of less than or equal to about ⅛″, and more preferably of about 1/16″. As shown in FIG. 4B, in one embodiment, the gasket 20 is provided as a continuous band of material that forms a seal around the periphery of the second major surface 19 of the fastening strip 10, forming a sealed area therein. Of course, multiple gaskets can be formed on the fastening strip to provide multiple sealed areas that surround punctures. In an alternative embodiment, as shown in, for example, FIG. 5B discussed below, the gasket can be provided as a continuous strip of material that is coextensive or substantially coextensive (e.g., from 75-110% of the surface area of) with the major surface 19 of planar member 18.
Turning again to the frontal view of FIG. 4A, the major surface 17 of the planar member 18 has an adhesive layer 22 thereon. In embodiments, adhesive layer 22 is pre-applied to the surface 17 during manufacture and protected by a release strip 24 until use. The release strip may comprise, for example, a strip of polyethylene, silicone or wax coated paper or vinyl. A primer for the release strip may or may not be used depending on the selected release strip and adhesive. In an alternative embodiment, the adhesive layer 22 is not pre-applied to the planar member 18 but the surface 17 of planar member 18 comprises a material and/or has a surface texture that readily accepts an adhesive layer, which is applied during installation. Exemplary adhesives include pressure sensitive adhesives, such as a double-sided tape like Scotch adhesive transfer tape 969 by 3M Corporation of St. Paul, Minn., acrylic based solvent borne adhesives such as Morstik™ by Rohm&Haas of Philadelphia, Pa. or 0175 Adhesive by Velcro USA of Manchester, N.H., water based adhesives such as Robond™ by Rohm&Hass, and rubber based adhesives such as Velcro USA's 19 adhesive or Tempo™ (0114) adhesive and Liquid Nails® Drywall Adhesive BC-150 available from ICI Paints of Cleveland, Ohio.
FIG. 5A is an enlarged partial cross-sectional view of fastening strip 10 installed over a vapor retarder 12 with fasteners, i.e., staple 16A, securing the vapor retarder 12 and fastening strip 10 (as shown in FIGS. 4A-4C) to a stud 14. Drywall 30 is disposed over the fastening strip 10 and adhered thereto by adhesive layer 22. Band-type gasket layer 20 forms a seal around the perimeter of the area 32 where fastener 16A punctures vapor barrier 12.
FIG. 5B is an enlarged partial cross-sectional view of a second embodiment of a fastening strip, labeled as 10A. The features shown in FIG. 5B are identical to those shown in FIG. 5A only the gasket member 20A is shown as a continuous strip of material (as described above) through which the fastener 16A passes. In this embodiment, the gasket 20A forms a seal more proximate (e.g., directly over or adjacent) to the puncture locations 32.
As described above, the fastening strip described herein helps to preserve the integrity of the vapor barrier by sealing around punctures formed in the retarder layer. Still further, the fastening strip facilitates use of vapor retarder products with adhesive drywall applications. The fastening strip provides a much improved surface (vis a vis the vapor barrier) for receiving adhesive, either pre-applied or applied during installation, for mating with installed drywall. Still further, the fastening strip can be used as a shim for shimming up studs for providing a flat surface for receiving the drywall. Fastening strips as described herein can even be provided in different thicknesses for this use, or have a thickness that can be varied either by using additional thin shims added to the front major surface of the fastening strip, such with an adhesive or adding additional thickness to the gasket material of the fastening strip.
An installation method using the fastening strip described herein is now described. First, one or more insulation batts are installed in a cavity defined between structural supports, such as vertical wooden studs. A vapor retarder sheet is then disposed over the insulation batts, on the interior facing side of the wall structure, and across at least two studs spaced by the cavity. At least one fastening strip is provided. More preferably, at least one fastening strip is provided for each stud to which the vapor retarder is to be secured. The fastening strip can be provided with pre-applied adhesive layer 22 and/or a release liner 24. The fastening strip is aligned vertically over the vapor retarder along the stud and one or more fasteners, preferably a plurality of spaced fasteners (such as staples, screws or nails), is driven through the fastening strip, into and through the vapor retarder and into the stud, thereby securing both the fastening strip and vapor retarder. The gasket(s) on the fastening strip provides one or more seals around the nail/staple punctures formed in the vapor retarder. This step is preferably repeated at each stud to secure the vapor retarder. As described above, the fastening strips may also be used as shims to provide an aligned surface to which the drywall is provided. Next, adhesive is applied to the major surface 17, if not pre-applied. If the fastening strip is manufactured with an adhesive layer and provided with a release liner, the release liner is removed (either before or after the fastening step) to expose the adhesive layer. Drywall is then disposed over the wall structure and in contact with the adhesive layer. The adhesive layer at least temporarily secures the drywall to the wall. Nails, screws or other fasteners are then driven through the drywall and the fastening strip and into the studs to secure the drywall. Finishing steps are then performed as will be understood by those in the art. An analogous method applies for installation of a vapor retarder in a ceiling or floor of a building.
Although the invention has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly to include other variants and embodiments of the invention that may be made by those skilled in the art without departing from the scope and range of equivalents of the invention.

Claims

1. An article for use in securing a vapor retarder to a structure comprising:

a support member having first and second major surfaces, said first major surface oriented for receiving fasteners for fastening said member and vapor retarder to said structure; and

a gasket disposed on said second major surface.

2. The article of claim 1, wherein said gasket comprises a continuous strip or band of compressible material.

3. The article of claim 1, wherein said gasket comprises synthetic or natural rubber, silicone, polyurethane foam or epoxy.

4. The article of claim 1, further comprising a layer of adhesive disposed on said first major surface.

5. The article of claim 4, further comprising a release strip disposed over said adhesive layer.

6. The article of claim 1, wherein said member has a thickness of 0.5″ or less and a width of 1.5″ or less.

7. The article of claim 1, wherein said member has a thickness of 0.25″ or less and a width of 1.0″ or less.

8. The article of claim 1, wherein said first major surface is planar.

9. A wall structure, comprising:

a plurality of structural supports having an insulation material disposed therebetween;

at least one vapor retarder sheet disposed over said structural supports and between said insulation material and an interior facing surface of said wall structure;

at least one fastening article comprising a support member having first and second major surfaces, and a gasket disposed on said second major surface, said fastening article disposed over at least one of said structural supports with said gasket disposed on said vapor retarder; and

at least one fastener disposed through said fastening article and said vapor retarder into said structural supports for securing said vapor retarder and fastening article.

10. The wall structure of claim 9, wherein the wall structure further comprises brick, building paper, oriented strand board sheathing, and interior drywall.

11. The wall structure of claim 9, wherein the wall structure further comprises stucco, a polyolefin house wrap, exterior gypsum sheathing, and interior drywall.

12. The wall structure of claim 9, wherein said gasket comprises a continuous strip or band of compressible material.

13. The wall structure of claim 9, wherein said gasket comprises rubber or epoxy.

14. The wall structure of claim 9, further comprising a layer of adhesive disposed on said first major surface.

15. The wall structure of claim 14, further comprising a release strip disposed over said adhesive layer.

16. The wall structure of claim 14, further comprising drywall adhered to said first major surface with said adhesive.

17. The wall structure of claim 9, wherein said member has a thickness of 0.5″ or less and a width of 1.5″ or less.

18. The wall structure of claim 9, wherein said member has a thickness of 0.25″ or less and a width of 1.0″ or less.

19. A method, comprising:

installing a vapor retarder in a wall, floor or ceiling of a building, said vapor retarder installed across a cavity defined between at least two structural supports;

providing at least one fastening article comprising a support member having first and second major surfaces and a gasket disposed on said second major surface, said fastening article disposed over at least one of said structural supports with said gasket disposed on said vapor retarder; and

driving at least one fastener through said fastening article and said vapor retarder into said structural support for securing said vapor retarder and fastening article.

20. The method of claim 19, wherein said gasket comprises a continuous strip or band of compressible material.

21. The method of claim 19, wherein said gasket comprises natural or synthetic rubber, silicone, polyurethane foam or epoxy.

22. The method of claim 19, wherein said fastening article further comprises a layer of adhesive disposed on said first major surface with a release strip disposed over said adhesive layer, said method further comprising the step of removing said release strip and adhering drywall to said first major surface.

23. The method of claim 19, further comprising the step of applying a layer of adhesive to said first major surface and adhering drywall to said first major surface.

24. The method of claim 19, further comprising the step of shimming said wall structure with said at least one fastening strip and installing drywall over said fastening strip.

25. The method of claim 19, wherein said at least one fastener is driven through said gasket.