1. Field of Invention
The present invention relates generally to modular building construction materials and techniques.
More particularly, the invention relates to a membrane roofing system for buildings constructed from modular units, and a reinforced laminate tape to bridge and seal the gap at the roof between adjacent modules.
2. Description of Prior Art
One technique for constructing a building is to fabricate building modules at a manufacturing location, and then assemble the modules together at the building site. Construction of modular buildings in this manner requires bridging and sealing the gap between adjacent or side-by-side modules, particularly at the roof line, after the modules are secured in position. Building modules of this type are commonly provided with a membrane roofing sheet at the factory. Consequently, after assembly of the modules together in side-by-side relation, the gap between the membrane sheets of adjacent modules must be bridged and sealed to establish a weather proof roof system for the finished building.
Roofing membranes are conventionally made from one or more of the following, and other generally equivalent elastomeric/polymer compositions such as, but not limited to: EPDM, EPR, TPO, PVC, Neoprene, Butyl, Polyisobutylene, Halogenated Butyl, Halogenated Polyisobutylene, Isobutylene, reclaimed butyl, and natural rubber. Roofing membranes are typically provided with a thickness of between approximately 0.030 inch to 0.060 inch, the thickness depending on circumstances and characteristics desired, as well as on the specific composition and processing of the membrane.
In the construction of modular buildings, the gap at the roof line between the adjacent modules is typically less than 4 inches. One common technique to establish a joint between adjacent building modules is to install a stiff bridging member over the gap, and then apply an adhesive-backed protective membrane, typically provided in the form of a rolled tape, over the bridging material and overlapping onto the membrane roofing sheets of the adjacent modules. The tape establishes a water-tight seal between the modules, and the bridging material prevents sagging of the tape into the gap between the modules. Another technique available for sealing the roofing gap between adjacent modules is to use an adhesive-backed tape provided with a stiff, fully cured outer membrane that is reinforced with an embedded scrim.
However, there are drawbacks and disadvantages associated with such prior construction techniques. In the latter case, the reinforced outer membrane produces a non-conforming joint that can exhibit poor sealing characteristics. Consequently, that tape does not readily conform to irregular surfaces, and a high percentage of joints develop leaks, resulting from the imperfect-fitting nature of joints between manufactured modules (e.g., as from manufacturing tolerances), and from inherent uneven edge lifting of adjacent building modules as the modules expand and contract over time. The seal established with the separate bridging material is also a stiff, non-conforming seal that results in the same sealing problems as are experienced with the reinforced outer membrane seal. Use of the separate bridging material also results in substantial additional cost associated with the additional bridging materials and the additional labor and time required for preparation and installation of the bridging materials. As a result of the stiff, non-conforming nature, these prior seal arrangements are also difficult to cut through and disassemble or remove in the event that the modules are to be disassembled, or should inspection or repair of the joint or underlying structure become necessary.
A completed roofing system in which the gaps between adjacent building modules are flexibly sealed without the above-identified drawbacks and disadvantages would be advantageous by reducing leaks and increasing joint reliability, reducing installation costs, and promoting ease of removal, disassembly, inspection and repair activities.
The general aim of the present invention is to provide an improved roofing system for modular buildings.
Another aim of the invention is to provide materials and techniques for bridging and sealing the gaps between roofing membrane sheets of adjacent building modules, without the above-identified drawbacks and disadvantages associated with prior materials and techniques.
An important objective of the invention is to provide for construction of modular buildings without the need to use a separate bridging member spanning across the gap between adjacent modules.
Another important objective of the invention is to provide a roof-joint seal that is less expensive than prior seal arrangements utilizing separate bridging and seal materials.
Another important objective of the invention is to provide a flexible elastomeric seal that bridges imperfect fitting joints commonly associated with adjacent building modules, without sagging into the gap between the modules.
Another important objective of the invention is to provide an elastomeric seal with an integral, flexible, self-supporting bridging material.
Another important objective of the invention is to provide a reinforced, flexible elastomeric laminate seal between the membrane roof sheets of adjacent building modules, thereby completing the roof system of the finished building.
Another important objective of the invention is to provide a flexible elastomeric laminate seal that is also suitable for sealing between walls, concrete and other construction joints.
These and other objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
According to the invention, there is provided a reinforced, flexible, elastomeric, self-bridging laminate tape to bridge and seal the gap between membrane roof sheets of adjacent building modules, and to complete the roof system of the finished building.
One preferred embodiment tape to bridge and seal the joints between construction modules is provided with a tacky elastomeric adhesive membrane, a porous semi-rigid reinforcing scrim layer embedded in the elastomeric membrane such that the elastomer surrounds and extends through the integral openings or porosity of the reinforcing layer, an outer flexible, non-tacky protective membrane permanently adhered to and covering the outer side of the tacky elastomeric membrane, and a release strip temporarily adhered to and covering the inner side of the tacky membrane prior to installation of the tape. The outer non-tacky layer is provided as a separate membrane layer that is permanently adhered to the outer side of the tacky adhesive layer, either as part of the tape manufacturing process or at the job site after application of the tape to the roof. The reinforcing layer is provided in the form of an open-weave, porous, perforated, mesh, or other permeable structure strip that supports the weight of the tape when installed across a gap between modules, and that imparts the desired structural stiffness and flexibility characteristics of the tape. The elastomeric layers can be provided as non-cross-linked, partially cross-linked, or fully cross-linked layers, and they can be uncured, partially cured, or fully cured layers.
One preferred roofing system constructed in accordance with the invention includes membrane roofing sheets installed on adjacent building modules, and an elastomeric self-bridging laminate tape pursuant hereto installed across the gap between the roofing sheets of the adjacent modules. The building modules are secured in position adjacent one another, with factory installed membrane roofing sheets covering the modules. Adjacent edge portions of the membrane sheets are cleaned and primed in preparation for installation of the tape. The self-bridging tape is then laid along the roof joint, spanning across the gap and overlapping the adjacent cleaned and primed edge portions of the roof membrane sheets. The tacky side of the tape is adhered to the roof membranes, and the non-tacky protective layer covering the outer surface of the tacky elastomer is exposed to provide an exposed weather resistant roof surface across the gap. The reinforcing laminate is provided with a width that spans across the width of the gap, and is configured to provide sufficient structural transverse stiffness to prevent the tape from sagging into the gap, while maintaining sufficient flexibility to permit expansion and contraction between the building modules, and rolling and unrolling of the tape without development of leaks along the joint.
While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention.
Reference numerals shown in the drawings correspond to the following:
The present invention relates to a membrane roofing system for modular buildings, such as building 10 shown in
One prior technique for establishing a roofing joint between the membrane sheets of adjacent building modules is shown in
The tape 22 is adhesively secured over the bridging material 20 and to the membrane roofing sheets 14 along the length of the gap. The overlap between the tape and the membrane sheets is typically between 3 to 6 inches, with a more common overlap of approximately 4 inches. Cleaner and tape primer are used to prepare the membrane surfaces for optimum bonding with the tape. One suitable known primer includes a small percentage of butyl adhesive in a solvent base to encapsulate dust and dirt that remains after cleaning and to fill microscopic voids and cracks in the membrane substrate.
The tape 22 is provided in a roll, with release paper (e.g., Kraft paper) on the tacky underside (as installed), the release paper being removed from the tape as it is unrolled over the joint. An outer protective layer is provided over the joint 16, either as an outer layer integral with the tape, or as an additional strip that is adhered onto the outer exposed surface of the tape after the tape is secured in place over the bridging material. The tape (and outer protective layer) are then secured in position on the roof with pressure, typically by rolling a roller along the length and width thereof. The joint 16 is completed by sealing the butting, open and overlapping ends of the tape with a caulk sealant such as indicated at 26.
The roof joint 18 shown in
In accordance with one aspect of the present invention, a self-bridging laminate tape is provided to bridge a gap between adjacent building modules and sealably engage adjacent generally coextensive strips of roof membranes covering the modules at the adjacent edges of the modules, and thereby establish a sealing joint between membrane roofing sheets of adjacent building modules, and to establish a finished membrane roofing system for the modular building.
One embodiment of a self-bridging tape 30 according to the invention is shown in
In carrying out this aspect of the invention, the tape 30, shown in detailed cross-section in
The reinforcing layer 34, alternately referred to herein as scrim, is provided in the form of an open-weave strip of material comprising absorbent or loosely woven cloth, porous fiberglass fabric, wire or plastic screen-like mesh, perforated plastic or metal strip, or other porous or permeable material, e.g., generally flat material with a multiplicity of interstices, through which a non-solid may penetrate or be pressed or otherwise forced. The scrim extends the length of the tape, and is sufficiently wide to span the gap (e.g., 16a, 18a) between the modular building units. As discussed further below, the scrim is designated to produce, in combination with the tacky adhesive and protective outer layer, certain structural and flexibility characteristics in the tape. These characteristics include, but are not limited to supporting the weight of the unsupported center portion of the tape when laid over a gap between adjacent building modules.
The tacky adhesive layer 32 covers each side of the reinforcing scrim 34, and extends through the pores or perforations or openings of the scrim to establish an integral adhesive layer in which the scrim is embedded (see
The protective outer covering 36 and tacky adhesive layer 32 are formed from elastomeric compounds, and are preferably formed from material selected from, but not limited to, one or more of the following elastomer groups: EPDM, EPR, TPO, PVC, Neoprene, Butyl, Polyisobutylene, Halogenated Butyl, Halogenated Polyisobutylene, Isobutylene, reclaimed butyl, natural rubber and Polydimethylsiloxane (PDMS). The protective outer covering 36 and tacky adhesive layer 32 are further provided in either of an uncured condition, a partially cured condition, or a fully cured condition. The protective outer covering 36 is a non-tacky, non-adhesive layer, with a thickness of between approximately 0.030 to 0.060 inch. For aesthetic and functional compatibility, the protective outer covering is typically formed from the same or a similar base compound as the roofing membrane sheets with which the tape is to be used.
The tape 30 is provided in convenient widths for the roof joints to be bridged and sealed. With a typical roof gap of 4 inches or less between installed building modules, and to establish an overlap between the tape and each of the adjacent roofing membrane sheets at the generally coextensive edges of the building modules of 3 to 6 inches for sealing engagement therebetween, the tape is provided at between 9 to 18 inches wide, with the widest tape enabling overlap onto fresh roof membrane surface for reassembling along joints that were previously disassembled. To establish seal joints in new building construction, with a 4 inch gap and a 4 inch overlap, the preferred tape is provided with a width of 12 inches. Thus, a tape that is provided to bridge a specified maximum gap between adjacent building modules and to sealably engage adjacent generally coextensive strips of the roof membranes covering the modules will include an elastomeric adhesive layer 32 having a width substantially equal to the specified maximum gap (e.g., 4 inches in the examples discussed above) plus the aggregate widths of the coextensive edge strips of the roof membranes (e.g., 6 to 12 inches, or 8 inches in the examples discussed above), and a reinforcing layer 34 having a width of at least approximately 4 inches.
The tape 30 is characterized as being (i) sufficiently flexible longitudinally to permit its being provided in a roll for storage, shipment, handling and unrolling onto the roof, and (ii) sufficiently flexible transversely (a) to conform to uneven edges between adjacent modules, and (b) to permit relative movement between the edges of the modules, without developing leaks, yet (iii) sufficiently rigid transversely when laid across the gap between adjacent modules to establish a self-supporting, non-sagging bridge over the gap. The scrim, in cooperation with the outer protective layer and the tacky adhesive layer, are specified to meet these characteristics.
The optimum tape hereof results in the center of the applied tape being fully self-supporting, with essentially zero sagging in the center of the tape. However, those skilled in the roofing membrane arts will recognize that the benefits of the invention will be achieved provided the scrim is specified such that the center of the tape sags no more than between approximately ¼ inch and ½ inch when applied over the roof gap. In other words, a tape that exhibits a maximum of this small deformation will not detrimentally affect the performance of the roofing system established therewith. Accordingly, a tape in accordance with the invention is sufficiently rigid transversely to form a self supporting bridge resistant to detrimental sagging (greater than approximately ½ inch) into the gap between the building modules when positioned over the gap with the tacky lower side adhered to the coextensive edge strips of the roof membranes.
In one preferred embodiment, the tape 30 is formed with a tacky adhesive layer (32) that is a blend comprising primarily butyl in an uncured condition mixed with other polymers, some of which are in a semi-cured condition, resulting in a semi-cured adhesive layer, the adhesive layer having a width of 9 to 18 inches, and a thickness of 0.040 to 0.050 inch; a reinforcing layer (34) in the form of a plastic polypropylene (or polyethylene) screen-like mesh (see
These designations result in a self-supporting tape that exhibits the previously identified characteristics, and that is capable of reliably bridging and sealing gaps between adjacent modules. Alternate preferred designations of the tape constituents will meet the performance characteristics of the above-designated tape construction. However, it will be understood that the stiffness and flexibility characteristics of the scrim material will be the primary factors in obtaining characteristics comparable with the above-designated embodiment.
A preferred method of forming the above-designated self-bridging tape 30 is a continuous conveyor-type process that includes the following:
(A) providing the release paper on a linearly moving conveyor,
(B) extruding the butyl adhesive blend (from processing mixers) onto the moving release paper,
(C) introducing the scrim onto the exposed face of the adhesive mixture and the elastomeric protective layer onto the scrim layer,
(D) passing the stacked release paper, adhesive layer, scrim and elastomeric protective layer continuously through one or more sets of opposing rollers to embed the scrim into the adhesive layer and to establish an initial adhesion between the adhesive layer and the elastomeric protective layer, and
(E) rolling the tape into tight rolls of predetermined lengths for stocking and delivery purposes.
Alternate methods of forming a self-bridging tape in accordance herewith will be readily devised by those skilled in the adhesive manufacturing arts. By way of example, and without limiting effect, the finished layer of reinforced tacky elastomer may be provided by extruding a first adhesive layer onto the release paper, laying the scrim strip onto the first adhesive layer, and then extruding a second adhesive layer onto the scrim such that the two adhesive layers will merge into a cohesive reinforced layer upon passing through the pressure rollers.
In carrying another aspect of the invention, the seal joints 42 and 44 of the finished roof system 40 of the building 10 are established by
(A) preparing strips along the edges of adjacent membrane roofing liners 14 with a cleaner and tape primer,
(B) optionally installing insulation in the gap 16a, 18a to reduce heating and cooling losses from the building,
(C) unrolling the self-bridging tape 30 along the length of the gap between the adjacent modules, positioning the tape to overlap the cleaned and primed membrane surfaces, for an overlap of approximately 4 inches, and removing the release paper 38 from the underside of the tape as it is unrolled into position over the gap,
(D) securing the tape to the membrane sheets, in position over the gap, with pressure applied to the outer protective cover such as with a roller along the length and width thereof, and
(E) sealing the butting, open and overlapping ends of the tape with a caulk sealant 26.
In an alternate embodiment, the self-bridging tape 50, shown in detailed cross-section in
In a second alternate embodiment, the self-bridging tape 60, shown in detailed cross-section in
In accordance with yet another aspect of the invention, the self-bridging tape disclosed herein may also be used to bridge and seal gaps between other structural construction members. For example, the tape may be used to seal gaps between walls, floors, concrete and other joints encountered in construction of buildings and other similar structures. The tape 60 without the protective cured layer may be used, for example, to bond a metal cap in position on the roof of a building, and may be used in combination with a tape 30, 40 having the cured layer for such purposes. The tape may also be used to seal joints such as in concrete sewer pipes, concrete culverts, concrete vaults. And the tape may be used to seal construction joints between the same as well as different substrates, including metal-to-metal, wood-to-wood, metal-to-wood, wood-to-concrete, metal-to-concrete, and rubber or plastic to itself or to any of the above-mentioned substrate materials. In particular, it has been learned that the reinforced tape hereof, made with adhesive butyl blends, is suitable to bond to each of these, properly cleaned, and primed as required, substrates. Alternately, as will be recognized by those skilled in the adhesive arts, a tacky adhesive layer of an alternate composition may be preferred for certain ones of these substrates. In such instances, the adhesive butyl will be replaced by a tacky adhesive composition identified above to provide better adhesion with such substrates.
From the foregoing, it will be apparent that the present invention brings to the art a new and improved roofing system for modular building construction, and a unique tape which, by virtue of its self-bridging self-supporting, yet flexible characteristics, bridges and seals the joints between the membrane sheets of adjacent construction modules, and establishes a finished membrane roofing system therefor, without the need for a separate bridge material or a stiff reinforced outer protective layer of prior roof-joint bridging systems. Accordingly, the invention eliminates the material and labor costs associated with cutting and installing separate bridging material of prior joint sealing arrangements, provides a seal with increased flexibility to reduce leakage associated with prior arrangements, and promotes ease of removal for disassembly, inspection and repair.
This application claims priority under 35 USC §119(e) to U.S. Provisional Patent Application 60/423,069 filed Nov. 1, 2002, the entirety of which is incorporated by reference herein. This application is a continuation of U.S. patent application Ser. No. 10/701,153 filed Nov. 3, 2003, which is incorporated by reference herein. Reference to sequence listing, table, or computer program listing appendix submitted on a compact disc: N/A. Statement regarding federally sponsored research or development: N/A.
Number | Date | Country | |
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60423069 | Nov 2002 | US |
Number | Date | Country | |
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Parent | 10701153 | Nov 2003 | US |
Child | 13344707 | US |