HK1116529A - Flashing method using air infiltration blocking skirt - Google Patents

Description

Rain shielding method using air permeation to block lower hem

Background

1. Field of the invention

The present invention relates to an air infiltration blocking skirt (skert) and a method for using an air infiltration blocking skirt.

2. Background of the invention

Drainage methods commonly used in the installation of windows, doors, and other fenestration products ("windows") used in building construction employ sill pans (silpan) that open at the front (outside) of the window and seal at the back (inside) of the window. This allows moist air and wind driven rain to penetrate the window-wall interface from outside the building. The result of this is that the thermal performance of the window is reduced as the frame of the window is now exposed to the outside air, and at the same time the ageing of the internal seal, which is the main protective seal keeping air and water out of the building interior, is accelerated.

Windows may be particularly susceptible to air and water intrusion under the sill when subjected to high wind loads, such as with high rise buildings and geographic areas experiencing exposure to severe wind and wind driven rain. Because the windowsill pan is open to the front or outside of the building and sealed at the rear, there is no seal to prevent outside air (which may have a sufficiently different temperature and humidity than the air inside the building) from penetrating the exterior plane of the window, especially when the building exterior is subjected to high wind loads and wind-driven rain. This exposure affects the durability of the internal seal over time. Especially commercial and rimless windows, are more susceptible to air penetration under the bottom frame of the sill due to the inherent design of these windows, since they do not have protective edges that block the wind. Wind driven rain between the window frame and the sill pan introduces moisture into the internal seals and the window frame flashing (flashing) and may affect thermal performance, seal durability and proper drainage.

Summary of The Invention

The present invention relates to a method for flashing a window during installation of the window into a wall opening, by using an air infiltration blocking skirt comprising a sheet of weather resistant sheet material, a skirt having a top edge, a bottom edge and two side edges, and having a width at least equal to the width of the window and a length sufficient for the skirt to extend below the lowest part of the wall opening, wherein:

a) the top edge of the skirt is continuously connected along its width to the lower part of the window,

b) the window is mounted in an opening in the wall,

c) the side edges of the skirt are sealed to the wall whereby the skirt covers the exterior surface of the wall below the window and the bottom edge of the skirt is not completely sealed to the wall, thus maintaining the drainage channel.

The invention also relates to an air infiltration blocking skirt for use in the above method.

Definition of terms

The term "sill pan" refers to a shallow receptacle located in the sill portion of a rough wall opening in a building, which is open to the exterior of the building and sealed within the interior of the building, for drainage purposes.

The term "window" is used herein interchangeably with the term "fenestration product" to refer to any window or other fenestration product (e.g., door, vent, utility supply box, etc.) that is installed in a wall opening within a building.

The term "window sill" or "sill" refers to the bottom of a window frame. The window sill is generally horizontal.

The term "flashing" is used herein to alternatively refer to any rain-shielding product, such as self-adhesive rain-shielding products or other weather-resistant types suitable for use in building construction.

The term "flanged window" refers to a window, door, or other fenestration product that includes an edge or studded fin to cover any space between the window frame and the rough wall opening. The edges or fins may be integral with the door and window product or may be continuous.

The term "rimless window" refers to a window that does not include an edge or studded fin to cover any space between the window frame and the rough wall opening.

Brief Description of Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate presently contemplated embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is an installation front view (outside of a building) of a window using an air infiltration blocking skirt according to the present invention.

Figure 2 is an installation side view of a rimmed window using an air infiltration blocking skirt according to the invention.

Figure 3 is an installed side view of a rimless window using an air infiltration blocking skirt according to the present invention.

Detailed Description

Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Like reference symbols are used to designate like elements throughout the several views.

The present invention relates to a new rain shelter method that uses an air infiltration blocking skirt to prevent wind driven rain water from entering a wall opening in a building between an opening or sill pan and a window (or other fenestration product) mounted in the opening, and to reduce air infiltration past the plane of the exterior of the window while allowing moisture to drain from within the wall opening to the exterior of the building under the air infiltration blocking skirt below the window.

An air infiltration blocking skirt installed according to the present invention is shown in fig. 1. The air infiltration blocking skirt is intended to be mounted over, among other things, weather resistant materials typically employed in exterior covering materials, such as Tyvek ® HomeWrap ® available from nauer dupont (dupont) of wilmington, terawa. The air infiltration blocking skirt 10 (also referred to as "skirt") is comprised of a piece of weather resistant sheet material that is at least the full width of the opening in the wall 17. Thus, the skirt width must be wider than the width of the window 12 and sufficiently long for the skirt to extend below the lowest portion of the wall opening so that it can be secured to the wall 17. Preferably, the skirt extends at least about 4 inches below the lowest portion of the wall opening. The skirt may be secured to the wall along each side of the window by a flashing strip 15, as shown in fig. 1, or by other adhesive means along the sides of the window. The air infiltration blocking skirt is not sealed along the bottom of the skirt so that the skirt acts like a one-way check valve, as the skirt allows a drainage channel (as indicated by the arrow in fig. 1) to remain under the window through which water can flow out of the building, but the skirt does not allow wind to drive rain into the building. It should be noted that in order to completely protect the wall from moisture, the sill portion of the wall opening is advantageously covered with a sill flashing 13 by standard procedures known to builders and window installers.

Fig. 2 shows a side view of the window installation when the window 12 is a flanged window. A piece of deformable self-adhesive tape 10a, such as dupont's straighurflash ® flashing (available from dupont) or some other suitable adhesive tape, is placed on the top edge of the weather-resistant sheet material 10b of the skirt, leaving at least about 1 inch of adhesive remaining exposed. The exposed adhesive adheres to the outside of the edge on the sill of the window or to the bottom of the window frame sill as in the case of the rimless window in fig. 3. In each case, the adhesive continuously seals the skirt to the window along its entire width. The window is then put in place and the flashing side pieces are adhered along both sides of the window, sealing the window to the wall. As shown in fig. 1, the flashing side pieces are advantageously adhered to the wall over the skirt bottom, thus nailing the skirt edge down onto the wall. The drainage channel is maintained because the skirt is not sealed along the bottom edge of the skirt 10. The presence of the skirt covering the wall below the window blocks wind driven rain and air flow from penetrating the outer plane of the window.

The air infiltration blocking skirt may be made of any suitable weather resistant sheet material. Flash spun (flashspun) polyethylene sheets such as Tyvek ® HomeWrap ® (available from dupont) may be used.

A piece of adhesive tape having good adhesiveness is applied under the entire lengths of the left and right sides of the installed skirt to prevent the wind from damaging the skirt during the building construction of the building. For example, a self-adhesive flashing such as the StraightFlash ® from DuPont (available from DuPont) may be used.

Claims (7)

1. A method for sheltering a window from rain during installation of the window into a wall opening using an air infiltration blocking skirt comprising a sheet of weather resistant sheet material, the skirt having a top edge, a bottom edge and two side edges and having a width at least equal to the width of the window and a length sufficient for the skirt to extend below the lowermost portion of the wall opening, wherein:

a) the top edge of the skirt is continuously connected along its width to the lower part of the window,

b) the window is mounted in a wall opening,

c) the side edges of the skirt are sealed to the wall,

whereby the skirt covers the outer surface of the wall below the window and the bottom edge of said skirt is not completely sealed to the wall, thus maintaining the drainage channel.

2. The method of claim 1, wherein the air infiltration blocking skirt has a length sufficient for the skirt to extend at least about 4 inches below the lowest portion of the wall opening.

3. The method of claim 1, wherein the window is a rimless window having a lower surface and the air infiltration blocking skirt is attached to said lower surface of the window.

4. The method of claim 1, wherein the window is a flanged window having a lower edge including an outward side and an inward side, and the air infiltration blocking skirt is attached to the outward side of the window edge.

5. An air infiltration blocking skirt for use in a fenestration product in a wall opening of a building, comprising a weatherproof sheet material, and having a top edge and a bottom edge, wherein the top edge of the skirt has an adhesive surface adapted for use in attaching the skirt to the bottom end of the fenestration product, and the skirt is at least as wide as the wall opening and is of sufficient length to extend below the lowest portion of the wall opening.

6. The skirt of claim 5 wherein said length is sufficient to extend at least about 4 inches below the bottom of the wall opening.

7. The skirt of claim 5 wherein said weatherproof sheet material is a flash spun polyethylene sheet.