WO2002090702A1

WO2002090702A1 - Enveloped foam shim, fenestration installation kit and method for installing a fenestration

Info

Publication number: WO2002090702A1
Application number: PCT/US2001/014591
Authority: WO
Inventors: Kerry R. White; Kevin S. Heichel; Neal F. Mcmahon; Runyuan Bai; Michael Arne
Original assignee: Andersen Corporation
Priority date: 2001-05-04
Filing date: 2001-05-04
Publication date: 2002-11-14

Abstract

An enveloped foam shim for placement between a frame of a fenestration unit and a rough opening in a building structure is provided. A method of installing a fenestration unit utilizing an enveloped foam shim is also provided. A Fenestration unit installation kit is also provided.

Description

ENVELOPED FOAM SHIM , FENESTRATION INSTALLATION KIT AND METHOD FOR INSTALLING A FENESTRATION

Field of the Invention

The invention generally relates to fenestration units and the installation 5 thereof within a rough opening in a building structure. More specifically, the invention relates to the use of an enveloped foam shim between the fenestration unit and the rough opening.

Background

10 Background installation methods for installing fenestration units into rough openings have typically involved the use of a wood or plastic shim between the fenestration unit and the rough opening.

Summary of the Invention

15 An enveloped foam shim for placement between a frame of a fenestration unit and a rough opening in a building structure is provided. A method of installing a fenestration unit utilizing an enveloped foam shim is also provided. A fenestration unit installation kit is also provided.

20 Brief Description of the Drawings

Figs. 1A-1D are perspective views of the enveloped shim

Fig. 2A is a perspective view of a packaging system (with the package sidewall partially broken away for a roll of enveloped shim stock wound on a core.

Fig. 2B is a side-view of the package of Figure 2 showing adhesive backed 25 hold down tab 220.

Fig. 3 A shows a threaded screw fastener adapted to practice the self- centering installation method of the invention.

Fig. 3B shows alternative thread patterns standard thread (325) and modified buttress thread (320) for screw fasteners shown in Fig. 3 A. 30 Fig. 4A1-A3 shows preparation for installation and an installed window according to the present invention.

Fig. 4B shows a completed window installation using the enveloped shim and self-centering method of installation. Fig 5 shows the 10-year creep displacement for the window installation shown in Fig 4 for climatic conditions in Arizona for foam stiffness of 383 Pascals per meter and a screw span of 76 centimeters.

Fig 6 shows the 10 year creep displacement for the window installation shown in Fig 4 for climatic conditions in Minnesota for a foam stiffness of 383 Pascals per meter and a screw span of 76 centimeters.

Detailed Description of the Invention

For purposes of the invention, an elongate foam strip is any compressible member capable of being positioned between a framework of a rough opening and a frame of a fenestration unit such as a window or door. An elongate foam strip may include open cell foams, closed cell foams, reticulated foams and any other compressible member. The cross section of an elongate foam strip may be many different shapes including rectangular, oval, circular and others. For purposes of the invention, a lateral surface of an elongate foam strip includes all surfaces other than the ends of the elongate foam strip. In a foam strip having a rectangular end cross section, there are four lateral surfaces (as discussed below, two major and two minor surfaces). Alternatively, if the elongated foam strip is oval or circular in cross section, there is only one lateral surface on such an elongated foam strip.

For purposes of the invention, a film envelope is any film that covers a portion of the lateral surfaces of a foam strip wherein the film envelope is substantially impervious to air infiltration in the direction running from outside the building structure to inside the building structure. Figure 1A shows an embodiment of the enveloped foam shim (100) including open-celled foam strip (101), film envelope (102), envelope overhang top & bottom (103), film attachment means (115), front major surface (110) and rear major surface (112), right minor surface (111) and left minor surface (113), top end surface (114), and bottom end surface (116). Figure IB shows another embodiment of the enveloped foam shim having pressure-sensitive adhesive layer (104) applied to rear major surface (112) the PSA layer is covered and protected by release liner (105). Figure 1C shows the enveloped elliptical foam shim of Figure IB being drawn from a roll (120).

Figure ID shows a enveloped foam shim of Fig. IB having a rectangular cross section being withdrawn from roll Figure 2A shows a perspective view of a packaging system (with the package sidewall partially broken away for a roll of enveloped shim stock of Figure 1C wound on core (204) supported within carton (210) to permit rotation of the core for dispensing shim by pulling on the end of the shim stock. Open-celled foam (201) enclosed in thermoplastic film envelope (202). Carton (210) has flap (205) to provide ready access to contents.

Figure 2B shows how the exposed end (214) of the shim can be temporarily secured to the roll of shim stock by PSA adhesive backed tape strip (216), which may conveniently include a tab (218) to facilitate removal of strip (216). When it is desired to dispense a length of shim, the tab (218) is lifted, and tape strip (216) releases and the required length of shim pulled from the roll and cut using shears or utility knife. The tape strip can be repositioned on the cut end of the roll and the tab (218) pressed into contact with roll to keep it from unwinding further.

Figs. 3A and 3B show a threaded screw fastener with alternative thread patterns adapted to practice the self-centering installation method of the invention. FIGS. 3A-3B are schematic illustrations of fastener and thread details useful in practicing the self-centering installation method with the enveloped, open-cell foam shims, h this application, the composite thermoplastic frame member is fastened to the wooden rough opening members through a given thickness of enveloped foam shim. By expanding the bearing surface area of engagement between the fastener and the thermoplastic polymer composite frame members, a larger than conventional diameter fastener head 310 acts to stiffen the assembly. This helps to compensate for the leveraging or cantilevering that occurs across the generally unsupported fastener length passing through the shim. This leveraging can amplify pull-out, turning, and bending forces at the connection between the rough opening framing member and the mechanical fastener. Further, it is desirable that the diameter of the fastener point 350 be smaller than the minor diameter 340 of the fastener shank. This ensures a tight engagement between the fastener and the rough opening framing member. Another factor influencing the pullout value of a threaded fastener is the depth of the thread (i.e., the difference between the outer thread diameter 330 and the minor shank diameter 340). In general, the larger the difference, the greater the pullout resistance. Further, tooth profile is important. FIG. 3B compares the profiles of a standard screw thread 325 and a modified buttress thread 320. The modified buttress thread has a steeper thread with almost a flat top surface, versus the nearly symmetrical top and bottom slopes of the standard screw thread profile 325. This design contributes to greater torque resistance to loosening as well as higher pullout values. Fig. 4 shows the position of an outside stop and the attachment of the enveloped foam shim to vertical surface of the rough opening using staples to supplement the PSA shown in Figures 1C & ID and Figure 2A. At low temperatures PSA may not stick to the opening or window frame and stapling the shim may be necessary to effect attachment of shims to the rough opening or frame surfaces.

Fig. 4B shows the installation of a replacement of a double-hung window frame (404) within a rough construction opening (402) using the enveloped foam shim (410) and plurality of screw fasteners (405) and self-centering installation method of the invention. The envelope surrounding the lateral surface of open- celled foam shim minimizes air and moisture infiltration thus improving the energy efficiency of the installation by minimizing the intrusion of warm, cold, or moisture laden air into the interior of the structure. For installation of casement or glider window frames header gap (406) is filled with enveloped foam shim and adjusted using screw fasteners in the same manner as the vertical surfaces of double-hung windows. If bow 407 becomes excessive due to improper fastener spacing, high foam stiffness, or greater than anticipated thermal fluctuations in the use environment, may cause the installation to fail because the sash seizes within the frame.

Lateral Surface of the enveloped foam shim is defined as: The sum of the major and minor surface area:

Lateral Surface Area = 2(major surface + minor surface) for shims of rectangular cross-section shown in Figures lA-lC. Open Celled Foam

The open celled foams useful in practicing the invention include: any compressible thermoplastic foam including: PNC, PET, Polyurethane (PU), polyolefm (polyethylene, polypropylene, including minor amounts of alpha-olefin and diene monomers, vinyl polymers including styrene monomers. Open celled poly(ether-urethane) foam was used to prepare the examples arising from the finite- element-analysis described in more detail hereinbelow.

Reticulated Foam Reticulated foam can also be used to practice the invention.

The term "reticulated foam" is used herein as it is commonly used among those skilled in the art, to denote solid foamed materials where all intervening walls have been removed from the cells of the foam, leaving a network consisting essentially of interconnected fibers along the outlines of the cells formed during the foaming. This is achieved by known foam processing procedures applied to the foam after the cells have been formed. These procedures generally involve the use of caustic or thermal treatments of the foam that remove all "window walls" separating the cells, throughout the foam. Accordingly, such foams are limited to plastics that are susceptible to such treatments, since not all foamed plastics are.

Reticulated foams are thus distinct from foams in which the window walls are merely broken, or foams in which only the outermost window walls or skin have been removed by physical means. Reticulated foams, by virtue of their total lack of window walls, are highly permeable to gas and liquid alike, offering little resistance to fluid flow, indeed much less than those foams in which the window walls have been retained.

The pore size of the reticulated foam may vary. The present invention is of particular interest, however, for use with reticulated foams having from about 20 to about 65 pores per inch (50-165 pores per cm), measured linearly. Mechanical and Thermal properties of foams:

The data required for performing the finite element analysis, can be found in Polymeric Foams by Klempner and Frisch, Hanser Publishers, 1991. The entire disclosure of which is hereby incorporated by reference.

The following discussion is taken from Ashby & Jones, Engineering

Materials 2- An Introduction to Microstructures, Processing, and Design, Second edition, Butterworth-Heinemann, pages 252-265, the teaching of which is hereby incorporated by reference.

When foam is compressed, the stress-strain cure shows three regions. At small^' strains the foam deforms in a linear-elastic way: there is then a plateau of deformation at almost constant stress; and finally there is a region of densification as the cell walls crush together.

At small strains the cell walls at first bend, like little beams of modulus E_S) built in at both ends. The deflection can be calculated from simple beam theory for which the stiffness of a unit cell, and thus the modulus E of the foam in teπns of the length 1 and thickness t of the cell walls, which are directly related to the relative density for open cell foams, using:

Gives the foam modulus Ef as: Ef = E_s (p_f/p_s)²

Where E_f E_s and p_f p_s are Young's Modulii and densities of the foam and solid polymers respectively.

Real foams are well described by these formulae.

Note that foaming offers a vast range of modulus: the density ratio , (p_f /p_s ) can be varied from 0.5 to .005, a factor of 10⁺²'by processing thus allowing E to varied by a factor of 10⁺⁴' .

Means for attaching the film envelope to the foam surface include, but are not limited to: Heat staking, stitch bonding, adhesive bonding (application of a pattern of adhesive strips or micro-dots), ultra-sonic welding, selected microwave heating, heated needle thermal bonding.

Acceptable attachment means are those that do not permit tearing of the film envelope or shredding of the foam when the shim is sandwiched between a wooden member (2x4) (2x6) etc. and thermoplastic or thermoplastic composite frame profile and secured with a plurality of screw fasteners. If tearing of the film envelope or shredding of the foam occurs the attachment means is judged unacceptable.

PSA coatings and Release Liners PSA coatings (104 ) and Release Liners (105)

PSA coatings and Release Liners suitable for practicing embodiments of the invention shown in Figs IB, 1C, ID, and 2A are available from 3M (Maplewood, MN -55119) or Avery Dennison Corporation (Diamond Bar, CA-91765)

Figures 5 and 6 illustrate the effects of heat and compression on a fenestration unit frame. Over time fenestration unit frames bow or creep or bend. Generally, the greater the foam shim is compressed in its installed position, the greater the creep or bend or bowing of the frame over a period of time. This effect is shown in Figs. 5 and 6. There is therefore a trade-off in design of a foam shim between higher compression desired to allow proper operation of the shim to hold the window securely within the rough opening and lower compression to minimize bowing otherwise referred to as creeping of the fenestration frame.

The frames used in the experiments shown in Figs. 4A-D, 5 and 6 were all made of Fibrex™ material made by Andersen Corporation. The details of one embodiment method of installing fenestration units into a rough construction opening using an enveloped shim is now described. This embodiment is not to be construed as limiting the scope of the invention provided in the claims appended hereto but rather provides more detailed description of one embodiment: a) Providing: i) A rough construction opening having vertical and horizontal surfaces including a stop on the interior or exterior side of said opening, ii) An Installation stop, iii) A plurality of compressible, enveloped open-celled foam shims, iv) A fenestration unit having a plurality of corner apertures and center apertures adapted to receive adjustable screw fasteners, v) A plurality of adjustable screw fasteners b) Preparing said opening by attaching said installation stops if required and enveloped foam shims to the vertical surfaces of said opening c) Inserting said fenestration unit into said prepared opening by slightly inclining said unit from the vertical so that initial contact between unit and stop occurs at bottom or top of said opening, d) Rotating said unit toward the vertical so that said foam shims slightly compress as the unit comes into contact with said stops, e) Relieving kinks in said shims by vibrating the unit as it is rotated into place or if necessary by using a thin blade spatula to relieve said kinks; f) Leveling said unit; g) Fastening first opposing corners of said unit to corresponding to opening corner by inserting screw fasteners into corresponding apertures in first frame center apertures and tightening screw fasteners, h) Fastening first opposing centers of said unit to corresponding opening centers by inserting screw fasteners into corresponding apertures in first frame center apertures and tightening screw fasteners, i) Adjusting said succeeding opposing fasteners to square said unit and straighten jambs within said opening; j) Measuring the clearance gap between unit and opening adjacent said first center aperture, k) Inserting insulation in non-foam containing clearance gaps, 1) Attaching interior and exterior trim to finish unit installation. A further description of one embodiment method of installing according to the present invention now follows.

Installation Instructions for Enveloped Foam Shim Description: The Renewal Foam Shim refers to the 2.75" wide x 0.5" thick foam encased in a continuous plastic sheath that is designed to be used with Renewal insert windows in lieu of hard shims and fiberglass insulation. The foam is applied to the side jambs or head jamb only; it is never used at the sill.

The installation procedure is as follows:

1. Prepare Opening

Following standard Renewal installation instructions remove the sash, stops, and any hardware to prepare the opening for an interior or exterior installation or create a pocket for the new window.

2. Verify Foam Usage

Measure the frame height and width of the Renewal insert window then measure the opening height and width.

The foam shim can be used if the rough opening height and width is between 1/8" and 3/8" greater than the frame height and width. Do not use the foam if the gap is less than 1/8" as this may cause the frame to bow over time creating operational and performance problems. If the gap is greater than

3/8" the foam lacks sufficient force to compress the frame jambs.

3. Install Foam

Cut a length of foam equal to the side jambs and head jamb. Depending on whether the installation is from the interior or exterior install the foam as follows: • Interior Install: Place the foam in the opening so that the outside edge is spaced about 1/4" from the exterior stop. Beginning at the top or bottom staple the inside edge of the foam to the opening by placing staples every 4" to 6" along the length and within 1/2" of the inside edge of the foam.

• Exterior Install: Place the foam in the opening so that the inside edge is spaced about 1/4" the interior stop. Beginning at the top or bottom staple the outside edge of the foam to the opening by placing staples every 4" to 6" along the length and within 1/2" of the outside edge of the foam.

4. Install Window

Place the window into the opening sill first. Slowly push the frame all the way into the opening. Complete the installation in the normal manner by using the installation screws the straighten the jambs and square the window frame.

The above discussion and embodiments are not to be interpreted as limiting the claims. Rather, the scope of the present invention is provided by the claims below.

Claims

Claims:

1. An enveloped foam shim for placement between a frame of a fenestration unit and a rough opening in a building structure, the foam shim comprising:

(a) an elongate foam strip having first and second end surfaces and one or more lateral surfaces; and

(b) a film envelope covering a portion of the one or more lateral surfaces.

2. The foam shim of claim 1, wherein aportion of the film envelope is attached to a portion of the one or more lateral surfaces of the foam strip.

3. The foam shim of claim 2, wherein the attachment of a portion of the film envelope to a portion of the one or more lateral surfaces comprises heat staking.

4. The foam shim of claim 2, wherein the portion of the film envelope is attached to the portion of the one or more lateral surfaces of the foam strip by an adhesive.

5. The foam shim of claim 1 further comprising attachment means for securing a portion of said film envelope to at least a portion of said one or more lateral surfaces of said foam strip.

6. The foam shim of claim 1 wherein the foam strip comprises open-celled foam.

7. The foam shim of claim 6 wherein the foam strip comprises polyurethane.

8. The foam shim of claim 6 wherein the foam strip comprises polyethylene.

9. The foam shim of claim 6 wherein said open celled foam is reticulated foam.

10. The foam shim of claim 1 wherein the film envelope covers substantially all of the one or more lateral surfaces of the foam strip.

11. The foam shim of claim 1 wherein the film envelope includes an interior side facing the foam strip and an exterior side opposite the interior side, wherein the foam shim further comprises an adhesive attached to at least a portion of the exterior side of the film envelope adapted for attaching the foam shim to a rough opening framework.

12. A method for installing a fenestration unit in a rough opening in a building, wherein the rough opening is formed by a framework that has an inner surface, and wherein the fenestration unit includes a frame having an outer surface that fits within the rough opening such that the outer surface of the fenestration unit faces the inner surface of the framework of the rough opening, the method comprising:

(a) providing a foam shim comprising:

(i) an elongate foam strip having first and second end surfaces and one or more lateral surfaces; and

(ii) a film envelope surrounding a portion of the one or more lateral surfaces;

(b) attaching the foam shim to one of the surfaces comprising the inner surface of the framework of the rough opening and the outer surface of the frame of the fenestration unit;

(c) fastening the frame of the fenestration unit to the framework of the rough opening.

13. The method of claim 12 wherein providing the foam shim includes attaching a portion of the film envelope to a portion of the one or more lateral surfaces of the foam strip.

14. The method of claim 12 wherein attaching the foam shim to one of the surfaces comprising the inner surface of the framework of the rough opening and the outer surface of the fenestration comprises attaching the foam shim to the inner surface of the framework of the rough opening, wherein the method further comprises providing an installation stop and attaching the installation stop to the inner surface of the framework of the rough opening.

15. The method of claim 12 wherein attaching the foam shim to one of the surfaces comprising the inner surface and the outer surface, comprises adhesively attaching the foam shim to one of such surfaces.

16. The method of claim 15 wherein attaching the foam shim to one of the surfaces comprising the inner surface and the outer surface, comprises using a pressure sensitive adhesive to adhesively attach the foam shim to one of such surfaces.

17. The method of claim 12 wherein attaching the foam shim to one of the surfaces comprising the inner surface and the outer surface, comprises stapling the foam shim to one of such surfaces.

18. The method of claim 12 wherein fastening the frame of the fenestration unit to the framework of the rough opening comprises screwing one or more screws through the frame of the fenestration unit and into the framework of the rough opening.

19. The method of claim 19 wherein the screwing step also comprises screwing one or more screws through the foam shim.

20. The method of claim 14 wherein said rough opening has a bottom and a top and wherein the method further comprises inserting said fenestration unit into the rough opening by slightly inclining said unit from the vertical so that initial contact between the unit and the installation stop occurs at the bottom or the top of said opening.

21. The method of claim 20 further comprising wiggling said unit back and forth as it is rotated into the rough opening.

22. The method of claim 12 wherein the fastening step uses a plurality of fasteners and wherein the method further comprises adjusting one or more of the fasteners to square the fenestration unit within the rough opening.

23. A fenestration unit and installation kit comprising:

(a) a fenestration unit having a frame;

(b) an enveloped foam shim for placement between the frame of the fenestration unit and a rough opening in a building structure, the foam shim comprising:

(ii) a film envelope surrounding a portion of the one or more lateral surfaces.

24. The kit of claim 23, wherein a portion of the film envelope is attached to a portion of the one or more lateral surfaces of the foam strip.