Abstract:
A bulkhead door seal is a sealing device that provides effective sealing of the interface between a bulkhead door assembly and a top of a concrete foundation wall to which it is attached. It prevents air and water from intruding into basement spaces around the bulkhead door assembly. The present invention is made of a flexible material that is very durable in all types of climates and will not break down over time. It is positioned between the bulkhead door assembly mounting flange and the top of the foundation wall. It may be configured with an inner vertical lip so that driving rain will not enter the interior of the door assembly, a flat mounting surface to accept a door assembly mounting flange, and a sloping exterior surface to shed water off the foundation wall. The device may be manufactured in strips that are cut on the building site to custom fit the bulkhead and door assembly.

Description:
BACKGROUND 
     The invention relates generally to watertight and airtight seals and, more particularly, to a sealing device for use at the interface of a bulkhead door assembly and a concrete foundation wall. 
     Basement or cellar doors have a long history of use for providing means for accessing a basement or cellar of a dwelling structure from the outside by way of a set of stairs. Since these basement or cellar spaces beneath the dwelling structure are located wholly or partly below ground level, they were usually damp and seldom occupied as living spaces. As such, there was generally not a requirement for eliminating air and water seepage around the edges of the door or where the door attached to the foundation wall of the dwelling structure. 
     Through the use of modem construction techniques, basements have been made more habitable by eliminating moisture incursion from the surrounding soil and reducing the loss of heat. This improvement enabled the use of basement spaces for additional living space, and typically provided for bedrooms and recreation areas. Furthermore, it is very economical to finish off these spaces. These “finished” basement spaces are normally accessed from the inside of the dwelling. However, most state building codes require that a second means of egress be provided from a basement in case of a fire. Today, approximately 90% of new homes built with a basement have bulkheads that are covered by a bulkhead door assembly. These bulkhead door assemblies are usually fabricated from sheet metal and have flanges that are between 1¼ and 1½ inches wide for attaching the door assemblies to a top of a foundation wall. 
     Bulkhead door assemblies are prone to air and water leaks into the basements they are supposed to protect. The air and moisture causes damage to the door assembly and to the framing and structure of the house to which it is attached. The resulting problems include mold, mildew, and decay of the insulation and wood framing, as well as rust deterioration to the bulkhead door assembly itself. These problems often result from the manner in which the bulkhead door assembly is affixed to a foundation wall. The metal bulkhead door assembly is attached directly to the top of a concrete foundation wall by an attaching flange and is usually bolted down tight. The typical residential foundation wall is 10 inches thick, with about 6½ inches of level concrete wall top exposed to weather on the outside of the door assembly. Because the top of the foundation wall is flat or concave, when it rains, the water sits on the top of the wall and wicks between the concrete and the metal bulkhead door assembly into the basement. Driving rain further enhances the water leakage, which usually occurs more on the front section than on the sides of the door assembly. 
     It is possible to partly solve the problem of water leakage around a bulkhead door assembly by sloping the top of the concrete wall away from the bulkhead mounting flange so that water would tend to drain off the top of the foundation wall. This is not a common practice because of the difficulty and expense of providing the slope at the desired location. Another proposed solution to the leakage problem is to apply a sealant, such as silicone, to the edges of the bulkhead door assembly attaching flange to prevent air and water leakage. This solution is only temporary because the metal door attaching flange expands and contracts with temperature excursions while the foundation wall retains essentially constant dimensions. This movement eventually causes the sealant to pull away from the metal attaching flange, creating a void in the interface allowing water and air to enter. The problem is compounded in colder climates where the water that has entered freezes, causing the void in the sealant to enlarge and allow more air and water to enter. Another problem is that the top of the concrete foundation wall is uneven and not perfectly straight and level. Thus, when the flat metal of the attaching flange is placed over the uneven concrete surface, there are numerous voids between the metal flange and the concrete. These voids allow water and air to enter into the inside of the bulkhead door assembly. Therefore, the leakage problem associated with basement door assemblies has become an important issue in finished basement spaces in modem house construction. 
     For the foregoing reasons, there is a need, therefore for a sealing device that allows a means for effectively sealing the interface between the mounting flange of a bulkhead door assembly and the top of a concrete foundation wall to which it is attached, in order to prevent air and water from intruding into basement spaces. This device must be inexpensive to manufacture, and must be capable of being easily installed at the construction site. 
     SUMMARY 
     The present invention is directed to a device that satisfies these needs. The present invention provides for a sealing device that allows a means for effectively sealing the interface between the mounting flange of a bulkhead door assembly and the top of a concrete foundation wall to which it is attached, in order to prevent air and water from intruding into basement spaces. This device is inexpensive to manufacture, and is capable of being easily installed at the construction site. 
     The present invention is a manufactured sealing strip made from a flexible material, like silicone or neoprene rubber, that is very durable in all types of climates and will not break down over time. It is positioned between the bulkhead door assembly mounting flange and the top of the concrete foundation wall. The device is configured to have a cross section that may have an inner lip so that driving rain will not enter the interior of the bulkhead door assembly, a flat portion on which the metal bulkhead door mounting flange can be positioned, and a sloping surface on the outside of the door assembly to shed water off the top of the concrete wall. The device is manufactured in straight strips and can be cut at the building site to custom fit any bulkhead and door assembly. It is not only capable of providing an air tight and water tight seal when fastened down to the top of the foundation wall, but it also sheds water due to the external sloping configuration. 
     A device having features of the present invention comprises an elongated strip of semi-flexible material having a top surface, a bottom surface, and a thickness, the bottom surface being substantially flat for being adhesively attached to a top of a concrete foundation wall, the top surface having a shape for mating with a side bottom flange and a front channel of a bulkhead door assembly, and the thickness being compressed when the side bottom flange and the front channel is secured by an attachment means to the foundation wall. The elongated strip may be cut to predetermined lengths to match the perimeter dimensions of the side bottom flanges and the front channel of the bulkhead door assembly. Mitered comers may be formed where cut ends of the elongated strips meet at right angles. The formed mitered comers may be sealed with an seal adhesive. The elongated strip may have a width dimension that is substantially less than a width dimension of the foundation wall. The elongated strip may have a width dimension that is approximately equal to a width dimension of the foundation wall. The elongated strip may have a width dimension that is greater than a width dimension of the foundation wall for providing a drip edge that extends beyond the edge of the foundation wall. The adhesive attachment of the bottom surface to the top of the foundation wall may form an airtight and watertight seal. The top surface may have a flat surface for mating with the side bottom flange and the front channel of the bulkhead door assembly. The top surface may be flexibly mated with the side bottom flange and the front channel of the bulkhead door assembly. The mating of the side bottom flange and the front channel may form an airtight and a watertight seal. The shape of the top surface may include a vertical lip interior to the side bottom flange and front channel for blocking moisture seepage. The shape of the top surface may include a downward sloping surface exterior to the side bottom flange and front channel for draining moisture away from the bulkhead door assembly. The top surface for mating with the side bottom flange and the front channel may be recessed from the top of the downward sloping surface. The attachment means may be an expansion bolt. 
     In an alternate embodiment of the invention, a seal for a bulkhead door assembly comprises an elongated strip of semi-flexible material having a top surface, at least one side surface, a bottom surface, and a thickness, the top surface and side surface comprising a hard outer shell of the elongated strip, the interior and bottom surface of the elongated strip comprising a soft inner material, the top surface having a shape for mating with a side bottom flange and a front channel of a bulkhead door assembly, the bottom surface being substantially flat for being adhesively attached to a top of a concrete foundation wall, and the thickness being compressed when the side bottom flange and the front channel is secured by an attachment means to the foundation wall. The elongated strip may have a width dimension that is approximately equal to a width dimension of the foundation wall. The elongated strip may have a width dimension that is greater than a width dimension of the foundation wall for providing a drip edge that extends beyond the edge of the foundation wall. The adhesive attachment of the bottom surface to the top of the foundation wall may form an airtight and watertight seal. The top surface may have a flat surface for mating with the side bottom flange and the front channel of the bulkhead door assembly. The mating of the side bottom flange and the front channel may form an airtight and a watertight seal. The shape of the top surface may include a vertical lip interior to the side bottom flange and front channel for blocking moisture seepage. The shape of the top surface may include a downward sloping surface exterior to the side bottom flange and front channel for draining moisture away from the bulkhead door assembly. The top surface for mating with the side bottom flange and the front channel may be recessed from the top of the downward sloping surface. 
     In an alternate embodiment of the invention, a method for installing a seal for a bulkhead door assembly comprises cleaning a top of a concrete foundation wall, applying an adhesive to the top of the foundation wall, positioning a flat bottom of precut lengths of a bulkhead door seal on the adhesive, mounting a bulkhead door assembly on a top of the precut lengths of the bulkhead door seal, the top having a mounting surface for accepting the bulkhead door assembly, and securing the bulkhead door assembly to the foundation wall by attachment means. The precut length of the bulkhead door seal may be formed by measuring the concrete wall length dimension and cutting the door seal to the length dimension. The comer ends of the precut lengths of bulkhead door seal may be mitered and sealed to form a water tight connection. The method may further comprise providing comer adhesive strips for tighter comer connections between the ends of the precut lengths of bulkhead door seal. The attachment means may comprise forming holes in the seal and concrete wall at predetermined locations, and installing expansion bolts to compress the bulkhead door seal to form an airtight and watertight seal. 
     The present invention provides for a sealing device that allows a means for effectively sealing the interface between the mounting flange of a bulkhead door assembly and the top of a concrete foundation wall to which it is attached, in order to prevent air and water from intruding into basement spaces. This device is inexpensive to manufacture, and is capable of being easily installed at the construction site. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
     FIG. 1 shows an installation of a bulkhead door assembly attached to a concrete foundation wall that is typical of the existing building arts; 
     FIG.  2 A through FIG. 2C show sectional views of the attachment of bulkhead door assemblies to a concrete foundation wall that is typical of the existing building arts; 
     FIG.  3 A through FIG. 3C show sectional views of the attachment of bulkhead door assemblies to a concrete foundation wall that illustrates embodiments of the present invention; 
     FIG. 4 shows a partial view of a comer of a bulkhead door assembly mounted to a concrete foundation wall using existing techniques; 
     FIG. 5 shows a partial view of a comer of a bulkhead door assembly mounted to a concrete foundation wall using embodiments of the present invention; 
     FIG.  6 A through FIG. 6L show some cross-sectional variations of an embodiment of the present invention; 
     FIG.  7 A through FIG. 7F show some cross-sectional variations of another embodiment of the present invention; and 
     FIG.  8 A through FIG. 8C show the steps of installing a bulkhead door assembly on a concrete foundation wall using embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     Turning now to FIG. 1, FIG. 1 shows an installation  10  of a bulkhead door assembly  200  attached to a concrete foundation wall  100  that is typical of the existing building arts. The bulkhead door assembly  200  is usually fabricated of sheet steel and comprises a left side  210 , a top side  270  and a right side  220 . The top side  270  slopes downward to a top front  272 , and has a left door  240  and a right door  250  rotatably attached to it by hinges positioned towards the sides  210 ,  220 . The left door  240  and the right door  250  are shown in the closed position. The left door  240  has a left door front  242  and the right door  250  has a right door front  252 . The foundation wall  100  comprises a left wall  110 , a front wall  130 , and a right wall  120 . 
     Turning now to FIG.  2 A through FIG. 2C, FIG.  2 A through FIG. 2C show sectional views of the attachment of bulkhead door assemblies to a concrete foundation wall that is typical of the existing building arts. FIG. 2A illustrates the right side  220  and the door  250  of the bulkhead door assembly  200  shown in FIG. 1. A side bottom flange  226  is provided for attaching the bulkhead door assembly to the foundation wall  120 . The right side  220  of the door assembly is attached to the right foundation wall  120  by bolts  222  through the side bottom flange  226  located internal to the door assembly. The bulkhead door assembly left side is similarly attached to the left foundation wall. FIG. 2B illustrates the right side  224 , the side bottom flange  226  and door  250  of another type of bulkhead door assembly that has attachment means external to the bulkhead door assembly. The right side  224  is attached to the right foundation wall  120  by bolts  222  through the side bottom flange  226  located external to the door assembly. The bulkhead door assembly left side is similarly attached to the left foundation wall. FIG. 2C illustrates the front part of a bulkhead door assembly. A front channel  280  that connects the left side to the right side of the door assembly is attached to the front foundation wall  130  by bolts  222 . Also illustrated in FIG. 2C is a partial section of the right door front  252  shown in the closed position. 
     Turning now to FIG.  3 A through FIG. 3C, FIG.  3 A through FIG. 3C show sectional views of the attachment of bulkhead door assemblies to a concrete foundation wall that illustrates embodiments of the present invention. The sectional views show the right side bulkhead seal  320  and the front bulkhead seal  330  shaped so that there is an inside vertical lip  321 , a flat attaching surface  322  and outside slope  323 . FIG. 3A illustrates the right side  220  and the door  250  of the bulkhead door assembly  200  shown in FIG. 1. A side bottom flange  226  is provided for attaching the bulkhead door assembly to the foundation wall  120 . Positioned between the bulkhead door assembly right side  220  and the right foundation wall  120  is a right bulkhead seal  320 , a preferred embodiment of the present invention. The right bulkhead seal  320  is attached to the top of the foundation right wall  120  with an adhesive so that this interface is both airtight and water tight. The right side  220  of the door assembly is attached to the right foundation wall  120  by bolts  222  through the side bottom flange  226 , located internal to the door assembly and that extend through the bulkhead seal  320  into the foundation wall  120 . Because of the slope of the bulkhead seal  320  causes water to drain off the bulkhead seal  320 , and the bolts  222  cause a tight fit between the door assembly right side  220  and the bulkhead seal  320 , this interface is also airtight and watertight. The bulkhead door assembly left side is similarly attached to the left foundation wall through a bulkhead seal. FIG. 3B illustrates the right side  224  and door  250  of another type of bulkhead door assembly that has attachment means external to the bulkhead door assembly. Positioned between the bulkhead door assembly right side  224  and the right foundation wall  120  is a right bulkhead seal  320 , a preferred embodiment of the present invention. The right bulkhead seal  320  is attached to the top of the foundation right wall  120  with an adhesive so that this interface is both airtight and watertight. The right side  224  of the door assembly is attached to the right foundation wall  120  by bolts  222  through the side bottom flange  226 , located external to the door assembly and that extend through the bulkhead seal into the side foundation wall  120 . Because of the slope of the bulkhead seal  320  causes water to drain off the bulkhead seal  320 , and the bolts  222  cause a tight fit between the door assembly right side  224  and the bulkhead seal  320 , this interface is also airtight and watertight. The bulkhead door assembly left side is similarly attached to the left foundation wall. FIG. 3C illustrates the front part of a bulkhead door assembly. A front channel  280  of the bulkhead door assembly connects the left side to the right side of the door assembly. Positioned between the front channel  280  and the front foundation wall  130  is a front bulkhead seal  330 , a preferred embodiment of the present invention. The front bulkhead seal  330  is attached to the top of the foundation front wall  130  with an adhesive so that the interface is airtight and watertight. The front channel  280  is attached to the front foundation wall by bolts  222  that extend through the front bulkhead seal  330  into the front foundation wall  130 . Because of the slope of the bulkhead seal  330  and the tight fit between the bulkhead seal  330  and the front channel  280 , this interface is also airtight and watertight. Also illustrated in FIG. 3C is a partial section of the right door front  252  shown in the closed position. 
     Turning now to FIG. 4, FIG. 4 shows a partial view of a comer of a bulkhead door assembly with doors in a closed position and mounted to a concrete foundation wall using existing techniques. Illustrated in FIG. 4 is a left foundation wall  110  and a front foundation wall  130 . The parts of the bulkhead door assembly illustrated in FIG. 4 include the left side  210 , the top side  270 , the top front  272 , the left door  240 , and the left door front  242 . 
     Turning now to FIG. 5, FIG. 5 shows a partial view of a comer of a bulkhead door assembly mounted to a concrete foundation wall using embodiments of the present invention. Although these figures depict the right side of a bulkhead door assembly, the left side and front are similarly attached using the same bulkhead seal configuration. FIG. 5 illustrates a left bulkhead seal  310  attached to a left foundation wall  110  with an adhesive and a front bulkhead seal  330  attached to a front foundation wall with an adhesive. The door assembly left side  210  and the top front  272  are attached to the foundation left wall  110  and the foundation front wall  130 , respectively, by bolts that are located internal to the door assembly and that extend through the bulkhead left seal  310  and front seal  330  into the foundation left wall  110  and front wall  130 . The left seal  310  and the front seal  330  have been mitered at a 45° angle and attached together with a sealing adhesive at the comer  340 . The right side of the bulkhead door assembly is similarly attached to the right foundation wall through a bulkhead seal. 
     Turning now to FIG.  6 A through FIG. 6L, FIG.  6 A through FIG. 6L show some cross-sectional variations of an embodiment of the present invention. All of the figures depict a sectional view of a right side  220  of a bulkhead door assembly attached through a bulkhead seal to the top of a concrete foundation wall  120  by bolts  222  through the side bottom flange  226 . FIG. 6A shows a bulkhead seal  400  that completely covers the top of the foundation wall  120  and has an interior lip  401 , a downward sloping exterior surface  403 , and a flat mounting surface  402  recessed below the interior vertical lip  401  and the exterior surface  403 . FIG. 6B shows a bulkhead seal  405  that completely covers the top of the foundation wall  120  and has a downward sloping exterior surface  407  and a flat mounting surface  406  below recessed below a top of the sloping surface  405 . FIG. 6C shows a bulkhead seal  410  that completely covers the top of the foundation wall  120  and has a flat top mounting surface  411 , and a downward sloping exterior surface  412 . FIG. 6D shows a bulkhead seal  415  that completely covers the top of the foundation wall  120  and has an interior vertical lip  416 , a downward sloping exterior surface  418 , a flat mounting surface  417  recessed below the top of the lip  416  and the top of the sloping surface  418 , and an exterior lip  419  that extends beyond the edge of the foundation wall  120 . The exterior lip  419  forms a drip edge to keep moisture away from the foundation wall  120 . FIG. 6E shows a bulkhead seal  420  that completely covers the top of the foundation wall  120  and has an interior vertical lip  421 , a downward sloping exterior surface  423 , a flat mounting surface  422  recessed below the top of the lip  4211  and an exterior lip  424  that extends beyond the edge of the foundation wall  120 . The exterior lip  424  forms a drip edge to keep moisture away from the foundation wall  120 . FIG. 6F shows a bulkhead seal  425  that completely covers the top of the foundation wall  120  and has an interior vertical lip  426 , a rounded downward sloping exterior surface  428 , and a flat mounting surface  427  recessed below the top of the interior lip  426  and the top of the exterior surface  428 . FIG. 6G shows a bulkhead seal  430  that partially covers the top of the foundation wall  120  and has an interior vertical lip  431 , a rounded downward sloping exterior surface  433 , and a flat mounting surface  432  recessed below the interior lip  431  and the top of the exterior surface  433 . FIG. 6H shows a bulkhead seal  435  that completely covers the top of the foundation wall  120  and has a rounded downward sloping exterior surface  437 , a flat mounting surface  436  recessed below the top of the exterior surface  437 , and an exterior lip  438  extending beyond the edge of the foundation wall  120 . The exterior lip  438  forms a drip edge to keep moisture away from the foundation wall  120 . FIG. 6I shows a bulkhead seal  440  that partially covers the top of the foundation wall  120  and has an interior vertical lip  441  and a flat mounting surface  442  recessed below the interior lip  441  that extends outward from the bulkhead door assembly right side  220 . FIG. 6J shows a bulkhead seal  445  that partially covers the top of the foundation wall  120  and has a rectangular cross-section, a flat interior surface  446 , a flat exterior surface  448 , and a flat mounting surface  447  that is coplanar with the interior surface  446  and the exterior surface  448 . FIG. 6K shows a bulkhead seal  450  that partially covers the top of the foundation wall  120  and has an flat interior and mounting surface  451 , and a downward sloping exterior surface  452 . FIG. 6L shows a bulkhead seal  455  that partially covers the top of the foundation wall  120  and has an rounded downward sloping interior vertical lip  456 , a rounded downward sloping exterior surface  458 , and a flat mounting surface  457  recessed below the top of the interior lip  456  and the top of the exterior surface  458 . There are many other cross-sectional configurations that may vary from those depicted, but that, nevertheless, fall within the scope of the present invention. 
     Turning now to FIG.  7 A through FIG. 7F, FIG.  7 A through FIG. 7F show some cross-sectional variations of another embodiment of the present invention. This embodiment includes a bulkhead seal that comprises a hard outer shell and a softer inner gasket material. Although these figures depict the right side of a bulkhead door assembly, the left side and front are similarly attached using the same bulkhead seal configuration. FIG. 7A shows a bulkhead seal  500  that completely covers the top of the foundation wall  120  and has a hard outer shell  502  and a softer inner gasket material  501 . The hard outer shell  502  may be a vinyl material and the inner gasket material  501  may be neoprene. The cross-sectional shape of the bulkhead seal  500  has an interior vertical lip  503 , a flat mounting surface  504  recessed below the top of the interior lip  503  for attaching a bulkhead door assembly right side  220  with bolts  222  through the side bottom flange  226 , and a downward sloping exterior surface  505 . FIG. 7B shows a bulkhead seal  510  that completely covers the top of the foundation wall  120  and has a hard outer shell  512  and a softer inner gasket material  511 . The cross-sectional shape of the bulkhead seal  510  has a downward sloping exterior surface  514  and a flat mounting surface  513  recessed below the top of the exterior surface for attaching a bulkhead door assembly right side  220  with bolts  222 . FIG. 7C shows a bulkhead seal  520  that completely covers the top of the foundation wall  120  and has a hard outer shell  522  and a softer inner gasket material  521 . The cross-sectional shape of the bulkhead seal  520  has a flat mounting surface  523  for attaching a bulkhead door assembly right side  220  with bolts  222 , and a downward sloping exterior surface  524 . FIG. 7D shows a bulkhead seal  530  that completely covers the top of the foundation wall  120  and has a hard outer shell  532  and a softer inner gasket material  531 . The cross-sectional shape of the bulkhead seal  530  has a continuous donwward sloping top surface  533  that provides an sloping interior surface, a sloping mounting surface for attaching a bulkhead door assembly right side  220  with bolts  222 , and a sloping exterior surface. FIG. 7E shows a bulkhead seal  540  that completely covers the top of the foundation wall  120  and has a hard outer shell  542  and a softer inner gasket material  651 . The cross-sectional shape of the bulkhead seal  540  has a flat top surface  543  that provides a flat interior surface, a flat mounting surface for attaching a bulkhead door assembly right side  220  with bolts  222 , and a flat exterior surface. FIG. 7F shows a bulkhead seal  550  that completely covers the top of the foundation wall  120  and has a hard outer shell  552  and a softer inner gasket material  551 . The cross-sectional shape of the bulkhead seal  550  has a rounded, downward sloping interior lip  553 , a float mounting surface  554  for attaching a bulkhead door assembly right side  220  worth bolts  222 , and a downward sloping exterior surface  555 . There are many other cross-sectional configurations that may vary from those depicted, but that, nevertheless, fall within the scope of the present invention. 
     Turning now to FIG.  8 A through FIG. 8C, FIG.  8 A through FIG. 8C show the steps of installing a bulkhead door assembly on a concrete foundation wall using embodiments of the present invention. FIG. 8A shows a section of a concrete foundation wall  100  for providing access to a basement of a building. An opening in the foundation wall  150  that supports the building is enclosed by a left foundation wall  110  a front foundation wall  130 , and a right foundation wall  120 . A stairway is normally mounted within space enclosed by these foundation walls to provide access to the basement. The tops of the foundation walls  110 ,  120 ,  130  are cleaned and an adhesive  160  is spread evenly over the top surfaces. FIG. 8B shows a left bulkhead seal  310  attached to the top of the left foundation wall  110  with adhesive  160 , a right bulkhead seal  320  attached to the top of the right foundation wall  120  with adhesive  160 , and a front bulkhead seal  330  attached to the top of the front foundation wall  130  with adhesive  160 . Prior to attachment to the foundation walls, the bulkhead seals are delivered to the construction site in the form of long strips. After measuring the length dimension of the tops of the left foundation wall  110 , the right foundation wall  120 , and the front foundation wall  130 , the bulkhead seal strips are cut to appropriate length, mitered at a 45° angle at the comer positions, and positioned on the adhesive  160  on the tops of the foundation walls, as shown in FIG.  8 B. Comer adhesive strips  170  positioned at the comers on top of the foundation walls prior to installing the bulkhead seals provide tighter comer connection between the mitered comers of the bulkhead seals. FIG. 8C shows a bulkhead door assembly  200  installed over the bulkhead seals  310 ,  320 ,  330 . The mitered comers  340  are sealed with an adhesive to provide an airtight and watertight connection. Bolt holes are drilled through the bulkhead seals and into the foundation wall tops at predetermined hole positions in the bulkhead door front and sides, and expansion bolts are installed to secure the bulkhead door assembly  200  tightly to the foundation wall  100 . This provides an airtight and watertight seal between the bulkhead door assembly  200  and the foundation wall  100 . 
     Although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiments herein.