Patent Publication Number: US-6701685-B2

Title: Waterproof roofing barrier

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a water barrier for a shingled roof that is applied to the roof deck, adjacent the eave of the roof, to prevent damage to the roof deck and an interior of a building from wind-blown rain and/or water buildup caused by ice dams or the accumulation of pine needles and leaves along the eave of the roof, and, in particular, to a waterproof roofing membrane, for application adjacent the eave of a roof, that includes an adhesive strip for bonding a lowermost course of asphalt shingles to an upper surface of the waterproof roofing membrane. 
     In cold climates, the eaves of a house roof or a building with a similar roof structure are normally colder than the upper portion of the roof. This difference in temperature often results in the buildup of snow and water at the eaves of the roof which freezes to form ice dams at the eaves. Water backs up behind the ice dams and, left standing behind the ice dams, leaks down around the nails securing shingles to the roof deck and damages the roof deck and the interior of the home or other building. In warmer climates a buildup of pine needles and leaves along the eaves of a roof can also form a dam that causes a water buildup on the roof which, left standing, leaks down around the nails securing shingles to the roof deck to damage the roof deck and the interior of the home or other building. 
     To prevent potential costly water damage from water buildup on a roof, waterproof roofing membranes are installed on the roof deck along the lengths of the roof eaves and extending upward from the lower edges of the roof eaves. To provide a waterproof barrier that protects the vulnerable part of the roof from water buildup caused by the presence of ice dams or pine needle and leaf dams, these waterproof roofing membranes are typically about 36 inches wide; are bonded to the deck along the lengths of the roof eaves; and seal around the shanks of nails used to secure asphalt shingles to the roof deck. Examples of such waterproof roofing membranes are waterproof roofing membranes sold by Johns Manville International, Inc., under the trade designations “ROOF DEFENDER” waterproofing membranes and “NORDSHIELD and SURE GRIP” waterproofing membranes. 
     When applying a lowermost course of asphalt shingles to a roof deck over one of these waterproof roofing membranes, a typical procedure followed by roofers to help seal and hold down the lowermost course of asphalt shingles at an eave edge, where the lift from winds may be the most severe, includes the following steps. Tabs are cut off or removed from a number of asphalt shingles whose combined length equals the length of the eave. The remainder of each asphalt shingle, typically about half of the asphalt shingle in width, is inverted or turned upside down so that the adhesive on what is normally the underside of the shingle, typically used to help secure the asphalt shingle to an underlayment, faces upward and these half shingles are nailed to the roof deck along the lower edge of the eave for the length of the eave. The first or lowermost course of full size asphalt shingles is then applied over these partial asphalt shingles and nailed to the roof deck with the adhesive on the now upper surfaces of the inverted partial asphalt shingles bonding to the undersides of the lowermost course of full size asphalt shingles to help seal and hold the lowermost course of asphalt shingles in place on the roof deck. While this procedure for applying the lowermost course of full size asphalt shingles to a roof deck is effective, the procedure is labor intensive and time consuming and there has remained a need to help seal and hold down a lowermost course of asphalt shingles on a roof deck that eliminates or greatly reduces the time and labor required to prepare the roof for the application of the lowermost course of full size shingles to the roof deck. 
     SUMMARY OF THE INVENTION 
     The waterproof roofing membrane of the present invention provides an inexpensive, labor and time saving solution to the above discussed problems. The waterproof roofing membrane of the present invention, which prevents water damage to a roof deck and an interior of a building through leakage from water buildup on an asphalt shingled roof, is preferably made of a fibrous mat, e.g. a glass fiber mat, saturated with a bituminous material. The waterproof roofing membrane is both waterproof and seals around nail penetrations through the membrane to form a watertight barrier. 
     The waterproof roofing membrane includes a first major surface with an adhesive thereon for bonding the waterproof roofing membrane to a roof deck along a lower portion of the roof deck adjacent the lower edge of the eave of the roof deck and a second major surface with an adhesive strip thereon for sealing a lowermost course of asphalt shingles to the membrane and helping to hold down this course of shingles which is more susceptible than other courses of shingles to being lifted off the roof deck by high winds. Preferably, the adhesive on the first major surface of the waterproof roofing membrane is coextensive with the first major surface of the membrane. A release sheet or film, which is removed immediately prior to applying and bonding the waterproof roofing membrane to a roof deck, covers the adhesive during storage, shipment and handling. Preferably, the adhesive on the second major surface of the waterproof roofing membrane is a strip of adhesive extending for the length of the membrane adjacent a lateral edge of the membrane adapted to be the lower lateral edge of the membrane, i.e. a lateral edge of the membrane that extends along the lower edge of a roof eave when the membrane is installed. The adhesive strip is a generally continuous layer or a patterned layer. A release sheet or film, which is removed immediately prior to applying and bonding the lowermost course of asphalt shingles to the waterproof roofing membrane, covers the adhesive layer during storage, shipment and handling. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of a first major surface of a waterproof roofing membrane of the present invention with the release sheet partially peeled away from the surface. 
     FIG. 2 is a schematic view of a second major surface of a waterproof roofing membrane of the present invention with the release sheet partially peeled away from adhesive strip on the surface. 
     FIG. 3 is a schematic end view of the waterproof roofing membrane of FIGS. 1 and 2. 
     FIG. 4 is a schematic perspective view of a waterproof roofing membrane of the present invention being applied to a lower portion of a roof deck adjacent a lower edge of the roof deck with the release sheet being peeled away from the membrane immediately prior to applying and bonding the membrane to the deck. 
     FIG. 5 is a schematic perspective view of a waterproof roofing membrane of the present invention that has been applied to a lower portion of a roof deck adjacent a lower edge of the roof deck with the release sheet that covers the adhesive strip on the second major surface of the membrane being peeled away from the adhesive strip immediately prior to applying and bonding a first course of asphalt shingles to the membrane. 
     FIG. 6 is a schematic perspective view of a waterproof roofing membrane of the present invention that has been applied to a lower portion of a roof deck adjacent a lower edge of the roof deck with a part of a first course of asphalt shingles bonded to the adhesive strip of the membrane. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As schematically shown in FIGS. 1-3, the waterproof roofing membrane  20  of the present invention includes a first major surface  22  with an adhesive  24  thereon for bonding the waterproof roofing membrane to a roof deck along a lower portion of the roof deck adjacent the lower edge of the eave of the roof deck and a second major surface  26  with an adhesive strip  28  thereon for sealing a lowermost course of asphalt shingles to the membrane and helping to hold down this course of shingles which is more susceptible than other courses of shingles to being lifted off the roof deck by high winds. Typically, the waterproof roofing membrane  20  is about thirty six inches wide, and comes in lengths of about thirty three feet or sixty seven. The first and second major surfaces  22  and  26  of the waterproof roofing membrane  20  are defined by the length and width of the waterproof roofing membrane. 
     The waterproof roofing membrane  20  is made of a woven or non-woven fibrous mat, e.g. a glass fiber mat, which has been saturated by a bituminous material. The waterproof roofing membrane is both waterproof and seals around nails passing through the membrane to form a watertight barrier. Examples of waterproof roofing membranes which can be used as the membrane of the waterproof roofing membrane  20  of the present invention, are waterproof roofing membranes sold by Johns Manville International, Inc., under the trade designations “ROOF DEFENDER” waterproofing membranes and “NORDSHIELD and SURE GRIP” waterproofing membranes. 
     Preferably, the adhesive layer or coating  24  (hereinafter “layer”) on the first major surface  22  of the waterproof roofing membrane  20  for bonding or adhering the waterproof roofing membrane to a roof deck is coextensive with the first major surface  22  of the membrane and is formed by the mastic or bituminous material with which the fibrous mat of the membrane is saturated. 
     A release sheet or film  30  covers the adhesive layer  24  during the storage, shipment and handling of the waterproof roofing membrane  20 . The release sheet  30  may be made of kraft paper, a polymeric film or some other sheet material which has the major surface that is in contact with the adhesive layer  24  treated with a silicone, a fluorocarbon polymer such a “TEFLON” or some other release agent with non-sticking properties that enables the release sheet  30  to be easily peeled away from the adhesive layer  24  immediately prior to applying and bonding the waterproof roofing membrane  20  to a roof deck. 
     Preferably, the adhesive on the second major surface  26  of the waterproof roofing membrane  20  is a continuous or patterned strip  28  of adhesive about one to about six inches wide, more preferably about two to about four inches wide, and extending for the length of the membrane. Preferably, the adhesive strip  28  is located intermediate a longitudinal centerline  32  of the waterproof roofing membrane and a lateral edge  34  of the waterproof roofing membrane adapted to be a lower edge of the waterproof roofing membrane with the lower edge  36  of the adhesive strip  28  being from about two inches to about seven inches from the lateral edge  34  of the waterproof roofing membrane  20 . Preferably, the adhesive used to form the adhesive strip  28  on the second major surface  26  of the waterproof roofing membrane  20  is a mastic or other sticky substance that causes a course of shingles to bond or adhere to the waterproof roofing membrane  20  when the shingles are applied to the waterproof roofing membrane. 
     A release sheet or film  38 , which preferably has a width about equal to the width of the adhesive strip  28 , covers the adhesive strip  28  during the storage, shipment and handling of the waterproof roofing membrane  20 . The release sheet  38  may be made of kraft paper, a polymeric film or some other sheet material which has the major surface that is in contact with the adhesive strip  28  treated with a silicone, a fluorocarbon polymer such a “TEFLON” or some other release agent with non-sticking properties that enables the release sheet  38  to be easily peeled away from the adhesive strip  28  immediately prior to applying and bonding a course of shingles to the waterproof roofing membrane  20 . 
     FIGS. 4 to  6  schematically show the waterproof roofing membrane  20  of the present invention being applied and bonded to a roof deck  40  and a lowermost course of shingles  42  being applied and bonded to the waterproof roofing membrane  20 . As shown in FIG. 4, the waterproof roofing membrane  20  is being unrolled from of roll  44  of the waterproof roofing membrane and applied and bonded to the roof deck  40 . The waterproof roofing membrane is applied to a lower portion of the roof deck  40 , adjacent the lower edge  46  of the roof or eave, with the lower lateral edge  34  of the waterproof roofing membrane at or adjacent and extending for the length of the lower edge  46  of the roof or eave. Immediately prior to applying and bonding the waterproof roofing membrane  20  to the roof deck  40 , the release sheet  30  is peeled away from the adhesive layer  24  on the first major surface of the waterproof roofing membrane to expose the adhesive layer  24 . 
     With the waterproof roofing membrane  20  bonded to the roof deck  40  and covering a lower portion of the roof deck adjacent the lower edge  46  of the roof or eave, as shown in FIG. 5, the release sheet  38  is removed from the adhesive strip  28 . Next the lowermost course of shingles  42  is applied and bonded to the waterproof roofing membrane  20  by the adhesive strip  28 , as shown in FIG. 6, and the lowermost course of shingles  42  and additional courses of shingles  48  are secured to the roof. 
     In describing the invention, certain embodiments have been used to illustrate the invention and the practices thereof. However, the invention is not limited to these specific embodiments as other embodiments and modifications within the spirit of the invention will readily occur to those skilled in the art on reading this specification. Thus, the invention is not intended to be limited to the specific embodiments disclosed, but is to be limited only by the claims appended hereto.