US20050011140A1

US20050011140A1 - Window flashing assembly

Info

Publication number: US20050011140A1
Application number: US10/900,747
Authority: US
Inventors: Dale Ackerman; Katarzyna Ackerman
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-05-09
Filing date: 2004-07-28
Publication date: 2005-01-20

Abstract

A window or door flashing assembly includes a weather resistive barrier that covers a portion of a wall around a rough opening. The barrier may be comprised of adhesive saturated open cell foam or scrim laminated between layers of impervious film A tapered sealing gasket that engages the inner surface of the door or window nailing flange or molding seals exterior air and moisture from the interior of the building. The barrier may extend into the rough opening and integrate with a sill pan.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation-in-part of prior U.S. patent application Ser. No. 10/114,756, filed Apr. 2, 2002, which is a continuation-in-part of U.S. patent application Ser. No. 09/567,866, filed May 9, 2000 now U.S. Pat. No. 6,305,130, the benefit of the filing dates being claimed under 35 U.S.C. § 120.

FIELD OF THE INVENTION

The present invention relates to building materials in general, and in particular, to seals, flashing, sill pans and flashing membrane for doors and windows.

BACKGROUND OF THE INVENTION

One of the most common failure points where water enters a building's envelope is around windows and doors. Water penetration is one of the most significant factors leading to premature failure of structures. Many windows and doors, whether they are aluminum or vinyl, are secured in the building's rough opening by a continuous nailing flange. As an example, the window is placed in the rough opening from the outside and secured using nail or screw fasteners that are driven through the window's nailing flange.
Installation methods vary significantly and range from as little as building paper lapping over or under the window flange to flashing materials being shingled in the rough opening prior to window installation, installation of sill pans, application of caulking installed from a tube caulk gun under the window flange, and various flashing or adhesive tapes applied over the window flange. Installation is often performed from ladders or scaffolding at various levels above the ground. Flashing materials are often misaligned or applied in an inconsistent manner that leaves wrinkles or voids in the material leading to leaks, i.e., direct water pathways to the underlying building materials. Adhesion to the numerous substrates is a major problem.
Current flashings are assembled from numerous separate components that when installed cover each other, making inspection of the completed flashing assembly extremely difficult. Further, since there is often a time lapse between installations of the various components, they are often damaged by wind, rain, or other mechanical disturbances.
Current materials used in flashing do not satisfy the various needs of sealing windows and doors nor a flashing barrier around the rough opening. Adhesive tapes provide a self sealing function for nail and staple penetrations. Unfortunately, they do not adhere to many substrates used in construction, are relatively expensive and many are incompatible with components they are adhered to. There application is extremely sensitive to moisture and cold with primers often being used with questionable success. Further, because they are often adhered directly to the buildings sheathing vapor diffusion is limited. This can result in decay of the underlying sheathing.
In other instances, materials used as the flashing barriers are of thin gauge materials made from polyethylene or polypropylene. Products like these provide little water penetration protection for nails and staples.
In products that are in current use adhesive caulking is typically applied between the window nailing flange and the building sheathing. Unfortunately caulk is rarely applied consistently or correctly and even when it is the continual expansion and contraction of components causes adhesive failure and opportunity for ultimate water penetration to the buildings structure. Further caulk adhesion failure is contributed to by low temperature and moisture at the time of installation.
Adhesive barriers applied over the nailing flange are often incompatible with the windows flange. They also often have insufficient thickness that when compressed around and over fasteners they do not create a proper seal.
Many windows eventually leak in areas of the window assembly or provide inadequate opportunity to seal the window at the outer wall face of the assembly. Other windows do not have a continuous window flange. In these instances a sill pan assembly must complement the flashing installation. Current sill pans are often custom fabricated from metal, are fabricated from self adhering flashing material while a few are manufactured from plastic materials. These methods variously; do not adequately provide sufficient support for the window assembly, do not provide adequate interface to other flashing materials, are difficult to seal to the window, are not adaptable to various window widths, do not provide a channel that allows water to be separated from the window frame or do not slope to the exterior of the building to assist moisture drainage.
The object of window and door flashing assemblies and sill pans is to adequately interface to surrounding weather resistive barriers, seal staple and other fastener penetrations, seal the window assembly to the flashing membrane, provide drainage at the sill when window leaks occur, adapt to various window depths that range from full sill width to as little as 1½″, protect window and structure materials from degradation and comply with the multitude of window and door manufacture and industry standards.
Given these problems, there is a need for an improved method of ensuring a weather-tight barrier for window installations.

SUMMARY OF THE INVENTION

The present invention is a flashing assembly for sealing around doors or windows. The present system combines integrated components that minimize material failure or installation error that will allow exterior water or air to penetrate the interior building structure. The object of the assembly is to provide an adaptable system that provides for vapor flow under the flashing, provides sealing redundancy and maximizes sealing performance. This current invention minimizes the number of components required in field installation.
The flashing assembly preferably includes a flashing membrane made from a adhesive saturated open cell foam laminated between solid film sheets with vapor flow creases that are positioned behind a nailing flange of a window or door. The foam adhesive flashing membrane is adhered to the building sheathing by staples or similar fasteners. The foam adhesive flashing membrane provides a water seal around nail and staple penetrations without use of exposed asphalt or butyl adhesives tapes that are often incompatible with other components and whose performance is inhibited by extreme temperatures and moisture. The sealing characteristic of the foam adhesive flashing membrane is enhanced by the adhesive being squeezed into the open cell structure during manufacture. The integration of the foam and adhesive also helps physically stabilize the adhesive at higher temperatures. While high density foam has strong sealing characteristics without an adhesive, its use in this application is uneconomic. The fabrication of the foam adhesive flashing membrane causes the wall side of the membrane to develop creases as it is straightened against the wall providing the opportunity for vapor to escape from behind membrane. The wall side film may be impressed with a pattern prior to fabrication to the foam further enhancing the films ability to be held off the wall.
The under flange seal is bonded to the flashing membrane or directly to the window flange, in its preferred embodiment having slanted parallel fins with serrated teeth, is compressed between the window or door nailing flange and the sheathing of the building thereby eliminating the use of caulk. The taper allows the sealing gasket to be uniformly compressed by the nailing flange while minimizing flange distortion and elevation from the wall. The serrated teeth of the sealing gasket enhance its ability to keep moisture and air from passing by the gasket.. The uniform size of the under flange seal provides consistent high performance by utilizing compression to create a seal, adapting to window flange movement and variations of the substrate. Field installation of caulk is inconsistent, generally too small in volume, does not adhere to many flashing materials and often does not cure prior to expansion that results in seal failure.
Integration of the over flange seal to the flashing membrane eliminates the requirement of sealing the two components in the field in adverse weather conditions. A factory seal is more reliable and only requires the seal to then be adhered to the window flange itself I the field. Use of closed cell foam adhesive assures compatibility and high bonding performance to the flange and full encapsulation of flange fasteners.
Integration of a sill pan to the flashing system that allow moisture to drain through channels to the exterior of the building structure, adapts to all window depths and manufactures support requirements, interlocks the sill base and molded corners while integrating to other flashing components provides additional moisture penetration protection with the simple easily installed components of the current invention. No other current system addresses all the required design considerations to comply with manufacture and industry standards.
Combining flashing membrane and closed cell foam adhesive with a release liner provides a flashing component that provides compatibility, broad temperature range and sealing performance not available from other current self adhering flashing systems. These systems are often insufficient in thickness to encapsulate flange fasteners, do not adhere in both hot and cold conditions and are blended for either a hot or cool environment while many weather patterns will expose the flashing system to both over the life of the installation.
The present inventions flashing components adapt the various versions currently accepted by industry standards at levels of performance and ease of installation unavailable by any other combination of products available.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 illustrates an extruded tapered profile seal that seals between a window flange and the wall sheathing.
FIG. 2 illustrates an extruded tapered profile seal with scalloped fins.
FIG. 3 illustrates an extruded tapered profile seal with fins.
FIG. 4 illustrates how a window flange flexes under stress.
FIG. 5 illustrates the fabrication path for foam adhesive flashing membrane.
FIG. 6 illustrates a profile of foam adhesive flashing membrane.
FIG. 7 illustrates flashing membrane with adhesive strip.
FIG. 8 illustrates an isometric view of FIG. 7.
FIG. 9 illustrates a profile of flashing membrane with an extruded tapered profile seal with fins, an inner flashing flap and an outer flashing flap.
FIG. 10 illustrates an isometric view of FIG. 9.
FIG. 11 illustrates a profile of flashing membrane with an extruded tapered profile seal, an outer flashing flap, and outer flange flap.
FIG. 12 illustrates an isometric view of FIG 11.
FIG. 13 illustrates flashing membrane, an outer flashing flap and adhesive tape positioned over a window nailing flange.
FIG. 14 illustrates an extruded tapered profile seal adhered to the inner surface of a window flange.
FIG. 15 illustrates a flashing membrane with inner flap, outer flap with an adhered extruded tapered profile seal positioned within the window rough opening and over the exterior wall sheathing. Adhesive tape is positioned over the window flange.
FIG. 16 illustrates FIG. 15 with the adhesive tape over the window flange replaced by an outer flange sealing flap that is integrally formed or bonded to the flashing membrane.
FIG. 17 illustrates an extruded sill pan base with parallel drain channels, exterior sloped drain channels formed to full width of sill and a variable window width rear sealing leg.
FIG. 18 illustrates the exterior sloped drain channels of FIG. 17 formed at partial width of sill for most vinyl and aluminum windows.
FIG. 19 illustrates an isometric view of sill pan molded corner with interlock teeth and sloped jamb gap.
FIG. 20 illustrates the reverse view of FIG. 19.
FIG. 21 illustrates the combined isometric view of the sill pan base and molded corner.
FIG. 22 illustrates an exploded view of the flashing assembly with sill pan.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is a window flashing assembly that provides an improved barrier to moisture.
FIG. 1 demonstrates a cross section of the under flange seal 6 from closed cell foam 1 that is formed at a width approximate to the width of a window nailing flange and is tapered 36 from one side to the other. As is demonstrated in FIG. 4 it is essential that the seal tapers to correspond with the compression strength of the nailing flange to avoid excessive flange deflection. In addition to stressing the flange, contrary to industry and manufacture standards, the flange elevation away from wall sheathing makes installation of trim around the window difficult. Current flashing systems rely on caulk to seal the window to the flashing membrane. Sealing caulks currently in use have a cure time varying from a few days to a few weeks. Testing shows that when these caulks are placed between materials having a low perm rating such as many flashing membranes and a window flange cure periods lengthen considerably. During the period that caulk is curing it is exposed to weather conditions that often cause areas of the seal to fail. Expansion, wind and rain are contributing factors. Caulk is rarely applied in the proper location and at the proper volume to affect a consistent seal. Caulk also often does not adhere to many of the flashing membranes in use or the other substrates utilized in many current systems. The present inventions under flange seal that is easily placed in the proper position, is consistent in volume and has consistent sealing performance regardless of environmental conditions is a significant improvement over existing methods. In some instances the under flange seal can be applied to areas of the window flange prior to shipment further reducing the opportunity for field errors. Ellingson in U.S. Pat. No. 4,720,936 defined various seal configurations related to door and window components that are regularly opened and closed like a door against the door frame. Ellingson does not address or suggest solutions for the unique issues of permanently sealing a window or door flange against exterior wall sheathing and flashing membranes.
FIG. 2 demonstrates the tapered 36 closed cell foam 1 under flange seal 6 with scalloped seal fins 29 and alternatively with added seal fin teeth 30. The scalloped shape and teeth provide independent surfaces to mate with the surface to be sealed with the sealing teeth providing additional higher tension points that inhibit passage of moisture or air. This variation may be formed from sheet foam thereby reducing manufacturing cost and introducing the option to use materials like polypropylene that may be heat bonded directly to the flashing membrane rather than being bonded by adhesives.
FIG. 3 demonstrates the tapered 36 closed cell foam 1 under flange seal 6 with angled seal fins 31 and alternatively with added seal fin teeth 30. The angled seal fins maximize potential seal depth while minimizing required compression.
FIG. 4 demonstrates a window assembly 39, the window flange inner surface 41 with an under flange seal 6 positioned for adhesion to the window flange 40. The window flange is manufactured as shown at 40 b while 40 a demonstrates typical deflection of the flange. The point furthest from the window 39 frame deflects the greatest amount. The design of the under flange seal therefore must correspond in density and shape to provide the maximum sealing potential while minimizing deflection. Testing demonstrates that an under flange seal that is not tapered as in the current invention results in the flange being significantly deformed and elevation of the flange off the wall sheathing resulting in difficulty in installation of window trim
FIG. 5 demonstrates fabrication of foam adhesive flashing membrane 9. A high strength film laminated to a low density foam 10 is fed through adhesive saturation rollers 28 where a sealing adhesive like butyl, bituminous, or synthetic 32 is compressed into the foam leaving sufficient surface residue that an outer film 23 will adhere to the assembly as it is fed over the vapor flow crease forming roller 11 as it is fabricated together with a compression roller 3. The completed assembly will block moisture, stabilize the adhesive by suspension in the foam or scrim, provides excellent seal around penetrations through the fabricated flashing membrane 8. Since this assembly is formed over a curved surface one side will crease when laid flat. Since this membrane does not adhere directly to wall sheathing or the window assembly, will seal the 200 typical nail and staple penetrations around a window or door and has creases that facilitate vapor movement it is a simple, economic and superior alternative to materials currently on the market. Pacific in U.S. Pat. No. 6,035,582 defines a foam film laminate material for flashing application constructed from closed cell foam without adhesive and no vapor seal crease. The present invention is superior as testing shows that foam required in the Pacific application must be high in density resulting in an uneconomic system for window assemblies. Further the fabrication defined by Pacific does not indicate formation of vapor seal creases.
FIG. 6 is a cross section of flashing membrane 8 fabricated to form a foam adhesive flashing membrane 9 comprised of an inner polyolefin film 12, open cell foam 22 and an outer film 23 that is formed with vapor flow creases 38.
FIG. 7 is a cross section view of flashing membrane 8 with an outer flashing flap 25 and a closed cell foam with adhesive and release liner 2. FIG. 8 is an isometric view of FIG. 7. Many current flashing materials that adhere over the window flange do not adequately encapsulate fasteners; do not perform in wide temperature ranges and discolor window assemblies. The current inventions use of a closed cell foam adhesive with poly release liner exceeds current product, like Fortifiber EZ Seal, performance in all of these areas.
FIG. 9 is a cross section view of flashing membrane 8 with an outer flashing flap 25, an inner flashing flap 13 and an under flange seal 6. FIG. 10 is an isometric view of FIG. 9. Combination of the flashing membrane with under flange seal combines the advantages of the previously described advantages in avoiding use of caulk while improving installation efficiency.
FIG. 11 is a cross section view of flashing membrane 8 of foam adhesive flashing membrane 9 with an outer flashing flap 25, an integrally formed or bonded outer flange sealing flap with adhesive and release liner 24, and an under flange seal 6 such seal formed of closed cell foam 1 having a tapered profile 36 angled sealing fins 31 with seal fin teeth 30. FIG. 12 is an isometric view of FIG. 10. This variation of the flashing assembly combines the advantages described in FIG. 9 with the addition of the integrally formed or bonded outer flange sealing flap with adhesive and release liner. Since the sealing flap is bonded in a controlled manufacturing environment performance of the over flange seal is improved significantly. The flap must only adhere to the window flange itself to be effective unlike all other systems that are exposed to weather environment and installation error at the time they are bonded to the weather membrane.
FIGS. 13, 14, 15 and 16 demonstrate a wall section with window sill 42, exterior wall sheathing 5, window assembly 39 having an integrally formed flange 40 having an inner surface 41.
FIG. 13 demonstrates placement of flashing membrane 8 with and outer flashing flap and a closed cell foam with adhesive and release liner 2 in relation to the window and wall.
FIG. 14 demonstrates placement of an under flange seal 6 in relation to the window and wall. In this application the seal will be compressed by the window flange inner surface 41 against the exterior wall sheathing 5 or flashing membrane (not shown).
FIG. 15 demonstrates placement of flashing membrane 8 with inner flashing flap 13, an outer flashing flap 25, and an under flange seal 6 in relation to the window and wall. Foam adhesive flashing tape with release liner 46 is positioned to seal over the top of the window flange 40 while overlapped onto the outer flashing flap 25.
FIG. 16 demonstrates placement flashing membrane 8 with inner flashing flap 13, an outer flashing flap 25, an integrally formed or bonded outer flange sealing flap with adhesive and release liner 24, and an under flange seal 6.
FIG. 17 is an isometric view of the full sill width extruded sill pan base 7 with lateral sill drain channels 45 having stepped depth 4 matching the exterior sloped drain channels 43 that are repeated along the length of the sill pan base, nail slot drain channel 21 is positioned to align with typical window nail slots, window flange support 35 assures stable fastening of the window flange across the sill, a molded corner interlock 44 provides alignment of the molded sill pan corner. A rear sill sealing leg 27 is adjusted to the window frame width and caulked into position or has an adhesive with release liner 33 to bond with the sill pan base 7. Sill pans are currently installed in an insignificant number of windows in the United States, however industry standards are being developed that will recommend their use for all windows. The current invention provides several layers of redundant protection against air and moisture intrusion into a building structure. The over flange seal, under flange seal, inner flap and seal of the inner side of the window frame to the inner flap all combine to limit sealing failure at the window and flashing membrane interface. Utilization of a sill pan protects against leaks within the window assembly itself and provides a relief valve for all other potential failures by allowing penetrated moisture to escape to the exterior. In Williams U.S. Pat. No. 6,401,401 numerous components are fabricated in the field, without use of a separate window shim manufacture support requirements that vary from 1″ to 3″ from the corner being suspended are not met, development of sloped drainage while providing level shim or window frame support is difficult, integration with interior trim and varying window widths require adaptation of the design by the installer. In Wark U.S. Pat. No. 6,385,925 the assembly must be specifically adapted to accommodate varying window frame depths, the window frame support is fragile expensive and intermittent rather than continuous as required by some major window and door manufactures. The volume of air infiltration at the sill is also significant due to the large area of opening between the sill pan and the window flange. The current inventions sill pan base is rugged, a simple extrusion of PVC or similar materials, can be cut to manufactures defined length for continuous support, allows moisture to drop to the bottom of the lateral sill drain channels minimizing exposure to wood window components, provides intermittent drainage relief to the exterior that is controlled in volume, covers the entire sill width making interior trim identical to current practice where sill pans are not installed and readily adapts to window frame widths ranging from full wall to the narrowest of frames.
FIG. 18 demonstrates the extruded sill pan base 7 with lateral sill drain channels 45, and an exterior sloped drain channel 43 formed to a width slightly greater than common vinyl and aluminum windows. The horizontal width of the rear sill sealing leg 27 is of sufficient width to cover the inner end of the exterior sloped drain channel 43 when installed for the described style of window.
FIG. 19 is an isometric view of the molded sill pan corner 34 having an exterior wall panel 20 having a sill pan interlock tabs 17, jamb panel 16 and sill panel 18 having a jamb gap sloped drain channel 14 and sill base interlock teeth 15. A significant portion of moisture entering the sill pan area falls into the pan at the rough opening jamb gap and drains to the exterior by the wall panel jamb gap drain channel 47. It is essential that this area be sloped to the exterior while allowing for suspension of the window frame at each corner to allow for expansion movement while meeting the requirements described at FIG. 17 for the sill pan base. In Wark the window frame supports are intermittently glued to the sill pan base during the manufacture process making end support imprecise, the molded corner is glued in the field in a manner that can lead to failure in addition to the previously described deficiencies. Williams does not directly address the sloped drainage and support issues. Other fabricated sill pans are formed from metal and flexible flashing tapes requiring significant field skill and labor for successful installation. The current invention sill pan molded corner is sloped at the rough opening gap that is drained by drainage channel, interlocks with the sill pan base where a butyl or other flexible adhesive insures successful seal while the window compresses the joint further ensuring the seal. The molded corner lateral interlock teeth can be positioned at varying positions providing the required variance in window frame support for most windows. The sill pan interlock tabs 17 on the molded sill pan corner further assures proper alignment of the parts. The sill pan corner is supported at the sill jamb corner to assure proper alignment of the assembly. The installation of the rear jamb sealing leg accommodates variation in the length the installer cuts the rear sill sealing leg.
FIG. 20 is an isometric reverse view of the molded sill pan corner 34 shown in FIG. 19 that additionally demonstrates the sill panel support leg 19.
FIG. 21 demonstrates the integration of the sill pan base 7 shown in FIGS. 17 and 18 and the sill pan molded corner 34 shown in FIGS. 19 and 20 with the addition of the rear jamb sealing leg 26 formed from material of the rear sill sealing leg 27 or sealing leg with adhesive and release liner 33.
FIG. 22 is an isometric exploded view of the window flashing assembly. The current window flashing assembly adapts to a wide variety of installation requirements. The under flange seal 6 can be installed directly to the inner surface of the window flange 41. The extruded sill pan base 7 and molded comers 34 can be utilized for further protection. Variations in flashing membrane 8 including utilization of the inventions foam adhesive flashing membrane 9 can be installed with or without an inner flashing flap 13. The flange may be sealed over the top with either an assembly providing an outer flange sealing flap with adhesive & release liner 24, a closed cell foam adhesive tape with release liner 46 or a flashing membrane with adhered closed cell foam adhesive with release liner 2. Murphy U.S. Pat. No. 6,725,610 requires field fabrication of a large number of components that contribute to installation error, utilizes flashing membranes that do not address sealing nail and staple penetrations that often exceed 200 per window, relies on caulk, as other systems do, to seal the window to the flashing membrane and does not provide for moisture release at the sill. Further, the components in Murphy do not adapt to design variations.
As can be seen from the above, the present invention provides a simple, convenient and cost effective mechanism for improving the flashing of windows.
While the present invention has been described with respect to its preferred embodiments, those skilled in the art will recognize that various changes may be made without departing from the scope of the present invention. It is therefore intended that the scope of the invention be determined solely from the following claims and the equivalents thereto.

Claims

1. The window arid door flashing assemblies under flange seal is constructed from compressible closed cell foam formed in varying widths approximate to the width of manufactured window and door nailing flanges;

and said under flange seal being tapered in depth across its width.

2. The under flange seal of claim 1 tapered surface is scalloped facilitating use of denser foam while maintaining optimal compression.

3. The tapered under flange seal of claim 1 is comprised of a series of slanted fins providing several individual barriers inhibiting moisture and air penetration.

4. The tapered under flange seal of claim 3 whose fins each have serrated teeth on the outer portion of the fin providing additional individual barriers inhibiting moisture penetration.

5. The under flange seal of claim 1 is adhered or bonded to a flashing membrane;

and the under flange seal is positioned on the flashing membrane such that when said flashing membrane is shingled around the rough opening the under flange seal is compressed between the windows nailing flange and the buildings sheathing;

6. The flashing membrane of claim 5 is adhered or bonded to the flashing membrane in such manner that an inner flashing flap may remain inward from the under flange seal with such inner flap being folded into the window or door rough opening.

7. The flashing membrane and under flange seal of claim 5 includes an outer flange sealing flap with adhesive and release liner that is integrally formed or bonded to the flashing membrane in such position that when the release liner is removed and the sealing flap is folded to the flashing membrane the outer sealing flap adhesive extends over the window nailing flange covering and adhering to nailing slots and fasteners.

8. A flashing membrane consisting of a layered composite made from a film that is laminated to cellular foam or scrim material saturated with a bituminous, butyl, synthetic rubber or acrylic based adhesive;

and that is laminated with a forming roller over the adhesive with an additional layer of impervious film such that as the composite is straightened vapor flow creases are formed in the additional film layer.

9. The flashing membrane of claim 8 with an adhered or bonded closed cell foam with exposed adhesive and release liner affixed along the length of one edge of the flashing membrane.

10. The flashing membrane of claim 8 where the tapered under flange seal of claim 1 is bonded or adhered to the length of the flashing membrane.

11. An extruded sill pan base extending the approximate width of the rough opening framing with lateral sill drain channels formed at regular intervals across the width of the base with such lateral sill drain channels formed at incremental depths moving from the inner to outer side of the sill rough opening;

and said extruded sill pan base having periodic exterior sloped drain channels;

and a sill pan window flange support integrally formed with the extruded sill pan base at an approximate 90 degree angle to the sill pan base that is greater in width than the typical window flange.

12. The sill pan base of claim 11 having a lateral nail slot drain channel extending the length of the sill pan base that is positioned such that the window flange nail slots overlay the drain channel.

13. The sill pan base of claim 11 having corner interlock grooves along the length of the lower inner side of the sill pan base and the lower inner side of the sill pan window flange support.

14. A molded sill pan corner oppositely formed for the right side and left side of the window rough opening formed from thin gauge plastic having an L shaped wall panel integrally formed at the inner sides of the L shape with a sill panel and jamb panel that oppose the wall panel at approximately 90 degrees with the sill and jamb panel being similarly joined;

and said sill panel having integrally formed sill base interlock teeth shaped such that when pressure is applied said teeth snap into the sill pan base lateral drain channels of claim 11 forming a water tight seal of the drain channel, said interlock teeth allowing adjustment of sill window frame support at the comers of the window from approximately 1″ to 3″ in length;

and said sill panel having an integrally formed exterior sloped jamb gap drain channel that adjoins the interlock teeth and the jamb panel.

15. The molded sill pan corner of claim 14 having a sill panel support leg that is an extension of the jamb panel past the intersection of that panel and the sill panel such that the corner is supported on the window or door sill rough framing.

16. The molded sill pan corner of claim 14 having a wall panel drain channel extending downward from the sill panel jamb gap drain channel to the lower edge of the L shaped wall panel.

17. The molded sill pan corner of claim 14 having sill pan interlock tabs that snap over the molded interlock channel of the sill pan base of claim 11.

18. An L shaped rear sill sealing leg where the longer leg of the L when adhered to the lateral sill drain channels of claim 11 spans several channels sufficient in width to allow adjustment of the rear seal to adapt to various window frame depths while the shorter L leg provides sufficient height to form a seal to the window frame, such adhesion functions being provided by tube caulk or a pre-applied adhesive with application release liner.

19. The rear sill sealing leg of claim 18 further formed by joining or molding two segments together at 90 degrees to form a jamb sealing leg that mates to the lower jamb corner of the flashing membrane positioned in the window rough opening framing, the sill panel of claim 14 and the rear sill sealing leg of claim 18 thereby forming a seal at each corner of the sill pan assembly.