Sill pan

Abstract

A method for forming a sill pan is provided that includes the measurement of a width and length of an opening sill to be sealed. A piece of flexible sill pan material is cut based on the measured opening sill. Fold lines and cuts are created in the piece to form the sill pan. The resulting sill pan is readily formed to have at least one attribute of self-adherence, draining without shims, nail hole self-sealing, and provision of dams without resort to frame cutting.

Claims

1. A method for forming a sill pan, said method comprising: measuring a width and length of an opening sill to be sealed; cutting a rectangular piece of flexible sill pan material based on the measured opening sill, said sill pan material having a first surface, a second surface opposite to the first surface, an inner edge, an outer edge, and a pair of side edges, where the inner edge and the outer edge are parallel to each other and perpendicular to the side edges of the flexible sill pan material; creating a set of fold lines in said rectangular piece of flexible sill pan material to define a back dam along the inner edge, a downward flap along the outer edge, and a seat between said back dam and said downward flap of the sill pan; placing said seat on the sill; vertically supporting said back dam with a metal angle; and placing a toe bead of sealant at a fold line between said seat and said back dam wherein creating said set of fold lines comprises: creating a first fold line on said first surface that defines a height of said back dam at a first distance measured from the inner edge; creating a set of two second fold lines on said first surf ace that are perpendicular to said first fold line and are parallel to said side edges at a second distance measured from both of said side edges; and creating a third fold line on said first surface parallel to said first fold line at a third distance as measured from the outer edge that defines a width of said seat of said sill pan for seating a window frame, and said downward flap.

2. The method of claim 1 wherein said second surface of said flexible sill pan material is waffled or dimpled.

3. The method of claim 1 wherein said flexible sill pan material is an aluminum membrane.

4. The method of claim 1 wherein said flexible sill pan material comprises a butyl backed adhesive.

5. A method for forming a sill pan, said method comprising: measuring a width and length of an opening sill to be sealed; cutting a rectangular piece of flexible sill pan material based on the measured opening sill, said sill pan material having a first surface, a second surface opposite to the first surface, an inner edge, an outer edge, and a pair of side edges, where the inner edge and the outer edge are parallel to each other and perpendicular to the side edges of the flexible sill pan material, and where the second surface of said flexible sill pan material is waffled or dimpled; creating a set of fold lines in said rectangular piece of flexible sill pan material to define the sill pan, wherein creating said set of fold lines comprises creating a first fold line on said first surface that defines a height of a back dam at a first distance measured from the inner edge, creating a set of two second fold lines on said first surface that are perpendicular to said first fold line and are parallel to said side edges at a second distance measured from both of said side edges, and creating a third fold line on said first surface parallel to said first fold line at a third distance as measured from the outer edge that defines a width of a seat of said sill pan for seating a window frame, and a downward flap; cutting said set of two second fold lines that extend from the outer edge until the third fold line; and cutting said first fold line from opposing sides from said side edges until said second fold lines to form opposing ends.

6. The method of claim 5 further comprising: folding said first fold line upward to create the back dam that is perpendicular to said seat; and folding said set of two second fold lines upward to form two side flaps and end dams that are perpendicular to said seat.

7. The method of claim 6 further comprising: bending said side flaps outward and perpendicular to said end dams; and bending said opposing ends upward to seal against said end dams.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGS. 1A-1D illustrate a method for forming a sill pan from a sheet material according to embodiments of the invention; and

(2) FIG. 2 is a side perspective cut away view of an installed sill pan according to embodiments of the invention.

DESCRIPTION OF THE INVENTION

(3) The present invention has utility for sealing window and door joints and provides a material and method of forming and application of the seal that can be used for a sill pan that has the advantages of a self-adhered membrane, but can drain without shims, and has sufficient sealing materials to seal around nail holes, while being thin enough to properly function and provide end and back dams without cutting the material.

(4) Embodiments of the inventive sill pan may be formed from a waffled aluminum membrane that has a thick butyl backed adhesive on the back, or other materials that inhibit moisture and can be used in the inventive method of forming sill pans. The waffled aluminum membrane is sold as a roll good that can be cut with scissors. The roll goods can be taken to an application or construction site and cut to size as required. In the inventive method for forming a sill pan, instead of cutting and sealing to form the pan, the material is folded to form the end and back dams so there is no hole or bonded surface. In the inventive method, the end dams and back dams of a sill pan may be formed to any required height. In forming the sill pan, the waffled aluminum membrane material is rigid enough to stand up by itself, so that the majority of a backing may be removed leaving the last one-inch, so the material can be turned up when the sill trim at the back of the window interior is installed. Alternatively in an embodiment, the back dam may be formed with a metal angle to which the back dam can be immediately bonded creating a free standing back dam. The waffle pattern on the face of the aluminum membrane creates a drainage course. If water were to travel through the window the pan will pick it up. The waffle pattern in the membrane material allows the water to drain to the exterior without putting the window to be sealed on shims. The pan can be sloped by gently sloping the sill framing or adding a continuous wood chair with very gentle sloping. The thick butyl backing of the membrane material acts to seal around penetrations. The aluminum surface is compatible with all materials currently in use as a flashing material. Packaged as a rolled good, the aluminum membrane allows for the expansion of the sill to the exterior to any amount the installer requires.

(5) In installations where metal sills are usually exposed, embodiments of the inventive sill pan are more appropriate for a nail-on window that used to be sealed with a nailing flange on all four sides. The concept used by builders today is to leave the sill open to allow and water that enters to drain out instead of entering the building, but to avoid air from entering the building to create an exterior air barrier. The waffled aluminum membrane material achieves the desired sealing performance by allowing drainage at the bottom, and sealing the window to the back dam with a butyl or polyurethane seal. Self-adhered membranes typically have a polyethylene face that serves as a water impervious barrier, and is not a good surface for sealant bonding. However, while the aluminum face of the waffled aluminum membrane material, used in embodiments of the inventive sill pan, also has a zero perm it still also provides a good sealing surface. The aluminum membrane is thick enough to provide rigidity, but thin enough to cut with scissors and to create a thin profile.

(6) Referring now to the figures, FIGS. 1A-1D illustrate an inventive method for forming a sill pan 32. It is noted that a waffled or dimpled aluminum membrane is the material used in the example embodiment shown; however additional sheet materials may be used to carry out the inventive method. In FIG. 1A, a rectangular sheet of flexible sill pan material 10 with the dimple or waffle side 12 showing is laid out and cut to a required size for a window sealing application. In general the inner 11 and outer 13 edges are along the long dimension of the cut sheet 10. In FIG. 1B, the smooth surface 14 of the flexible sill pan material 10 is shown, and the surface is measured and marked as follows with a first fold line 16 that defines the height of a back dam 20 at a first distance measured from the inner edge, and a second fold line 18 that defines a rectangular area 17 on opposing sides of the flexible sill pan made up of folded segments 26 and 28 (see FIG. 1C) that define side flaps and the end dams, respectively. The first fold line 16 is parallel to the long side of the rectangular sheet 10. The pair of second fold lines 18 are perpendicular to the first fold line 16 and are parallel to short side dimension of the sheet 10 at a second distance (D2) measured from the side edges 19. In FIG. 1C, a third fold line 22 is added that is parallel to the first fold line 16 at a third distance (D3) as measured from the outer edge, and bisects the sheet 10. Fold line 22 defines the width of the seat 30 of sill pan 10 for seating the window frame, and the downward flap 24 that extends down the wall 34 (see FIG. 2) below the window sill. The fold along third fold line 22 also creates a drip edge. Additionally in FIG. 1C, the back dam 20 is folded upward along fold line 16 relative to the seat 30. In FIG. 1D, a cut is made along second fold lines 18 that extend from the outer edge 13 until the third fold line 22, and the segments 26 and 28 that form the side flaps and the end dams, respectively are bent upward and perpendicular to the seat 30. The side flaps 26 are subsequently bent away from the seat 30 and made perpendicular to the end dams 28. The opposing ends 15 of back dam 20 that are defined by the area between the inner edge 11, first fold line 16, and second fold lines 18 are folded upward after a small cut is made to first fold line 16 that extends from the side edges 19 to the second fold line 18. The upward opposing ends 15 seal against the end dams 28. The entire sill pan 32 formed above is now ready to be placed in the opening for the window sealing application.

(7) FIG. 2 is a side perspective cut away view of an installed sill pan 32 in a building wall opening 34 prior to placement of a window frame (not shown) according to embodiments of the invention. As shown the downward flap 24 extends down the wall 34. Metal angle 36 provides vertical support to back dam 20, and seat section 30 of the flexible sill pan 32 fits onto the sill 38 of the window opening. A toe bead of sealant 40 is placed at the right angle bend between the seat 30 and back dam 20. When placing the window frame the bottom rear edge of the window frame is set into the toe bead of sealant 40.