Self-adhered roofing components, roofing system, and method

#The subject invention relates to waterproof self-adhering flashing cap strips, end lap connector cap sheets, and corner end lap connector cap sheets; roofing systems utilizing such self-adhering flashing cap strips, end lap connector cap sheets, and corner end lap connector cap sheets; the method of installing roofing systems utilizing such self-adhering flashing cap strips, end lap connector cap sheets, and corner end lap connector cap sheets; and flashing cap strip, end lap connector cap sheet, and corner end lap connector cap sheet assemblies used in the method of the subject invention. Typically, the flashing cap strips are used to interconnect cap sheets at roof surface intersections in the formation of waterproof cap sheet roofing layers; the end lap connector cap sheets are used to connect lengths of cap sheets at the job site; and the corner end lap connector cap sheets are used to connect cap sheets and form flashings at roof corners.

#The central field portions of roofing systems utilizing waterproof self-adhering cap sheets to form the cap sheet layers of the system do not rely on the application of heat by the installer to the overlapping lateral edge portions of successive cap sheets or the application by the installer of secondary adhesives to the overlapping lateral edge portions of the successive cap sheets to form watertight seams between the overlapping lateral edge portions of the successive cap sheets. However, in accordance with current installation procedures at roof surface intersections having a marked change in slope or direction (roof surface intersections such as, but not limited to: roof valleys formed by intersecting roof surface planes of a roof deck, perimeter wall surfaces projecting upward from flat roof decks; roof expansion joints with surfaces projecting upward from the general plane of a roof deck, etc.), installers use a flashing procedure that includes the application of heat and/or a secondary adhesive (preferably both) to the overlapped roofing granule coated lateral edge portions of the self-adhering cap sheets of the cap sheet layer to form watertight flashing seams between the successive cap sheets of the layer. This flashing procedure includes a step referred to as the heat sinking of the roofing granules on the overlapped lateral edge portions. In this step, installers apply heat with a hot air gun or similar heating tool to the roofing granule coated top lateral edge portions of the cap sheets that are to be overlapped by the lateral edge portions of adjacent cap sheets. The installers apply heat to the roofing granule coated top surfaces of these lateral edge portions and heat these edge portions until the self-adhering bitumen in these lateral edge portions is softened and semi-fluid. With the bitumen softened and semifluid, the roofing granules coating the top surfaces of these top lateral edge portions are pressed down into the bitumen to the extent practical to form better bonding surfaces for the flashing seams. After heat sinking the roofing granules on the lateral edge portions of the cap sheets to be overlapped, a secondary adhesive is typically applied between the overlapping lateral edge portions forming the flashing seams between the adjacent cap sheets of the flashings. While the above flashing procedure, if properly performed, makes a watertight seam between the overlapping lateral edge portions of the cap sheets forming a flashing of a cap sheet layer, the flashing procedure is time consuming and the skill of and the care employed by the installer in forming the flashing seam between such lateral edge portions of the cap sheets can greatly affect the integrity and water transmission retarding or barrier characteristics of the flashing seam. While current flashing installation procedures for cap sheet layers at roof surface intersections has been discussed in connection with waterproof self-adhering cap sheets, waterproof cap sheets that are not self-adhering would require the use of the same or similar procedures.

#Currently, as successive lengths of cap sheets must be joined at the job site, the end portions (head laps) of the successive lengths of cap sheets are connected together at the job site by heat sinking the granules on the cap sheet end portion to be overlapped and applying a secondary adhesive between the overlapped end portions of the cap sheets to bond the successive lengths of cap sheets together in a manner similar to the formation of flashing seams discussed above.

#FIG. 1 is a partial schematic view, from above, of a field portion of a self-adhered roofing system that may utilize the self-adhering flashing cap strip of the subject invention at roof surface intersections of the roofing system, the self-adhering end lap connector cap sheet of the subject invention to connect successive lengths of cap sheet used in the roofing system, and the self-adhering end lap connector cap sheet at corners of the roofing system. The view has portions broken away to better show certain of the roofing system components.

#FIG. 2 is a partial schematic perspective view of a base sheet assembly that may be used in the self-adhering roofing system of the subject invention.

#FIG. 3 is a transverse cross section through the base sheet assembly of FIG. 2 taken substantially along lines 3-3 of FIG. 2.

#As shown in FIG. 1, the field portion of a self-adhered roofing system 20 of the subject invention includes waterproof self-adhering base sheets 22 and cap sheets 24 that, preferably, are waterproof fire-retardant cap sheets. The waterproof self-adhering base sheets 22 of the roofing system 20 are self-adhered by watertight bonds both to each other to form inner roofing system layers and to underlying and overlying layers of the roofing system. The waterproof fire-retardant cap sheets 24 may be either self-adhering or non self-adhering. The non self-adhering waterproof fire-retardant cap sheets 24 are more fire-retardant than the self-adhering fire-retardant cap sheets. When non self-adhering waterproof fire-retardant cap sheets are utilized, the cap sheets 24 are adhered to each other, e.g. by a cold applied adhesive, and are adhered to an underlying layer formed of the self-adhering base sheets 22 by the self adhering top major surfaces of the self-adhering base sheets.

#In a preferred embodiment of the invention, the exposed top layer of the self-adhered roofing system 20 is formed by the waterproof fire-retardant cap sheets 24 and the inner roofing system layers of the self-adhered roof system 20 are formed by: one or more layers of the waterproof self-adhering base sheets 22 and a roof deck 26; or one or more layers of the waterproof self-adhering base sheets 22, one or more insulation layers 28, and a roof deck 26. In addition to the one or more inner roofing system layers formed by the waterproof self-adhering base sheets 22, for certain applications, the lowermost layer of the self-adhered roofing system 20, formed by the self-adhering base sheets 22, may be self-adhered to an inner layer formed of conventional base sheets that are in turn bonded by a conventional hot or cold applied adhesive to a roof deck 26 or an insulation layer 28.

#Each self-adhering inner layer of the self-adhered roofing system 20 is formed by a plurality of overlapping waterproof base sheets 22 that are self-adhered to the other base sheets of the self-adhering inner layer to form the self-adhering inner layer. In addition, the self-adhering base sheets 22 of the self-adhering inner layer thus formed are self adhered to overlying and underlying layers of the self-adhered roofing system. As shown in FIG. 1, a self-adhering layer 30 of self-adhering base sheets 22 is self-adhered to an overlying outer layer 32 of the fire-retardant cap sheets 24 and an underlying inner layer 34 of self-adhering base sheets 22 or conventional base sheets. Where the underlying layer 34 is also formed of self-adhering base sheets 22, the underlying layer may be self-adhered to the insulation layer 28, as shown in FIG. 1, to another base sheet layer, or directly to the roof deck 26. The roof deck 26 may be a wood, metal or concrete roof deck.