The present invention relates to a method and device for directing storm water once it has been captured on a flat or low-pitch roof toward the roof's drains and, more particularly, to an inflatable water resistant membrane forming a water repelling barrier for elevating a recessed area of such a roof.
Drainage of flat and low-pitch industrial roofs is complicated by the fact that they typically have low areas where rainwater tends to pool. Pooled water, subject to frequent freeze/thaw cycles, not only stresses the roofing materials and the roof deck but also forms an environment where mosquitoes and other insects can breed and which nurtures the growth of mold and fungus.
Because the roof drains for a typical industrial flat roof are arrayed on 10 to 30 foot centers, low areas can often be found, interspersed between these drains. In order to fill in these low areas and direct storm water toward the drains, tapered roof insulation can be used. Unfortunately, installing tapered roof insulation is a very costly, time-consuming process, entails extensive application of glues formulated from hazardous materials, and generates a tremendous amount of waste.
The object of this invention is to provide a lightweight, inflatable barrier for directing storm water captured on a flat or low-pitch roof towards the roof's drains and, in the process, reducing or eliminating the formation of puddles of standing water on the roof.
A further object is to provide such a barrier for directing storm water captured on a low-pitch roof which both slopes toward an outside edge and is enclosed by a parapet wall, in such a way that the water can drain out of one or more scuppers formed in the parapet wall rather than pooling next to it.
A still further object is to provide a low cost method for effectively elevating a flat roof's recessed areas, with the portion of each recessed area so elevated encompassing the maximum extent to which storm water pooled in that particular recessed area can spread laterally, in any given direction, across the roof.
A still further object is to provide a method for effectively elevating the recessed areas of a flat or low-pitch roof in such a way that a person practising the method can easily adjust the drainage patterns as the roof ages and settles.
In accordance with the present invention, there is provided an inflatable barrier system which includes at least one air impermeable membrane fabricated from a heat weldable, thermoplastic material; an air valve attached to the membrane by a clamping mechanism which creates an airtight seal between the valve and the membrane; and means, including a mounting bracket, for mechanically fastening the membrane, along its outer periphery, to the roof deck.
For those roofs with an existing roof covering made of a material compatible with the membrane and to which it can be heat welded, only a single membrane, joined by an airtight seal to the roof covering, is needed in order to construct an inflatable barrier. In each such inflatable barrier, the single membrane must be adequately sized and shaped not only to cover at least one of the roof's individual recessed areas and substantially overlap its edges but also define, in combination with the roof covering, an air pocket which is so dimensioned that once inflated, the single membrane protrudes generally upwardly from the surface of the roof, thereby obscuring and effectively elevating the recessed area which the single membrane covers.
Alternatively, for those roofs having a roof covering to which the membrane cannot be heat welded, either because of the material properties of the roof covering or of the membrane itself, or of both, two further embodiments of the inflatable barrier system are provided. In the first of these, the system includes at least one membrane fabricated from a non-heat weldable material such as EPDM or the like. The process of joining a non-heat weldable membrane to an existing roof covering in such a way as to form an airtight seal at the membrane/roof covering juncture preferably entails juxtaposing a double-sided butyl tape—a tape of the sticky, rubbery variety—or the like between the roof covering and the membrane by first affixing one of the tape's sticky sides to the roof covering proximate with the outer edges of a recessed area on the roof and then affixing the membrane to the tape's other sticky side. Glues, adhesives, and/or solvents can also be used in place of the double-sided butyl tape to achieve an airtight seal at the membrane/roof covering juncture.
For those roofs having a roof covering to which the membrane cannot be joined either by heat welding or by the use of a double-sided butyl tape, adhesives in general or the like, the inflatable barrier system preferably comprises at least one pair of membranes, each of which is in the form of a single layer of a heat weldable, thermoplastic material, with the membranes in each pair having generally the same shape and size.
The improved method for redirecting storm water captured on a flat or low-pitch roof towards the roof's drains includes the following steps:
For inflatable barrier systems having at least one membrane made of a non-heat weldable material, the joining of the membrane to the roof covering, preferably achieved with the use of a double-sided butyl tape or the like, creates both an airtight seal, at the membrane/tape/roof covering interface, and an air pocket. Defined by the membrane and the roof covering, the air pocket is disposed inwardly of the airtight seal. Once the membrane's outer perimeter has been mechanically fastened to the roof deck, the air pocket is then inflated with the use of an air valve mounted earlier on the membrane, and prior to its having been affixed to the roof covering.
The improved method for redirecting storm water is likewise modified in those situations in which a pair of membranes, each a single layer of a heat weldable, thermoplastic material, are heat welded together to form an inflatable barrier. There the two membranes share both the airtight seal, which is formed proximate with the perimeter of at least one of them, and the air pocket. Inflation of the latter is accomplished, using an air valve mounted earlier on one of the membranes, once the conjoined membrane pair has been mechanically fastened to the roof deck.
In the drawings, two basic embodiments of the inflatable barrier system according to the present invention are illustrated. These embodiments differ from each other in whether they utilize one air impermeable membrane 11, in combination with an existing roof covering 20, or two such membranes 11, 12 in order to create an inflatable air pocket 21, 22. Regardless of the number of membranes 11, 12, each membrane is preferably in the form of a single layer of a heat weldable, thermoplastic material. In either basic embodiment, once the inflatable barrier system has been assembled and mechanically fastened to the roof, covering at least one recessed area 10, and the air pocket 21, 22 has subsequently been inflated, a membrane 11, protruding generally upwardly from the roof's surface, effectively elevates the recessed area and redirects any storm water captured nearby to flow away from it and towards the roof's drains 30, 31 (
Prior to the installation of the inflatable barrier system, pooled water, if present, is pumped out of the recessed area 10 or otherwise dried using a mop or the like. A heat weldable, thermoplastic material such as the Carlisle TPO Sure-Weld from which the membrane 11 is to be cut is then laid out on the roof covering 20 so that the material not only substantially overlaps the recessed area's outer edges but also is oriented in such a way that when the yet-to-be created air pocket 21, 22 is properly inflated, water which would otherwise stand in the recessed area 10 will move instead toward a drain 30, 31. The membrane material is next cut to a size larger than the recessed area 10 in preparation for forming an airtight seal around the recessed area's perimeter between the membrane 11 and any existing thermoplastic roof covering 20, as well as an air pocket 21, 22 disposed inwardly of the airtight seal.
If, however, the nature of either the roof covering 20 or the membrane 11 itself is such that the membrane cannot be heat welded to the roof covering, the membrane can be joined thereto in such a way as to form an airtight seal 17 at the membrane/roof covering juncture with the use of a double-sided butyl tape (not shown) juxtaposed between the roof covering 20 and the membrane 11. Glues, adhesives, and/or solvents can also be used in place of the double-sided butyl tape to form an airtight seal 17.
Alternatively, a second membrane 12, preferably similar in shape and size to the membrane 11, can also be fabricated. With the membrane 12 juxtaposed between the membrane 11 and whatever covering 20 is present on the roof deck 38 or 40, the paired membranes 11, 12 are then heat welded or otherwise conjoined to form both an airtight seal 17, disposed proximate with the perimeter of at least one of them, and an air pocket 21, 22 (
Before the installer actually heat welds or otherwise joins the membrane 11 to the roof covering 20 or, alternately, to a second membrane 12, it is recommended that he first mount a Schroeder-type air valve or the like, such as a straight air valve 13 or an angled air valve 14, on the membrane 11 (
Not only can the inflatable barrier system according to the present invention be used to redirect water away from low spot(s) covered by membrane(s) 11 on a generally flat roof deck 38 but also the system's membrane 11 can be positioned so that it covers recessed area(s) 10 in a low-pitch roof 40, where the recessed area(s) are situated next to one or more parapet walls 41, 42 bounding the roof's outer edges (
Means for mechanically fastening the membrane 11, once it has been heat welded proximate with its outer periphery to either a compatible roof covering 20 or to a second membrane 12, or has been joined to the roof covering with the use of a double-sided butyl tape or with one or more adhesives, glues, solvents or like, preferably includes a mounting bracket with galvanized plates 19, each of which is affixed to at least one screw-like fastener 16 (
In an alternate embodiment, an elongated galvanized plate 15 is employed to press the outer edges of membranes 11, 12 against each other, sandwiching them between the plate and the roof deck's covering 20 with the use of fasteners 16 (
In a still further embodiment, a plurality of generally circular plates 19 with fasteners 16 which are spaced apart from each other at approximately 1 foot intervals is used to press amounting bracket against the outer edges of membrane 11, thus affixing these edges to a roof deck (
A cover strip 18, made of a heat sealable material, is preferably utilized to protect the mechanical fasteners as they hold the inflatable barrier system in place on either a roof deck 38 or a roof deck 40 in combination with a parapet wall. The strip 18 is preferably affixed along its outer edges to both the membrane 11 and the roof covering 20 so as to form airtight seals with both.
This application is a non-provisional application of the earlier filed provisional application Ser. No. 61/443,830, filed Feb. 17, 2011, and claims the benefit of the priority of the filing date of Feb. 17, 2011, pursuant to 35 U.S.C. Sec. 119(e).
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3807100 | Kuss | Apr 1974 | A |
3958373 | Stewart et al. | May 1976 | A |
4045934 | Sheahan et al. | Sep 1977 | A |
4399645 | Murphy et al. | Aug 1983 | A |
5259879 | Khattab et al. | Nov 1993 | A |
5966883 | Krusec et al. | Oct 1999 | A |
6006482 | Kelly | Dec 1999 | A |
Number | Date | Country | |
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20120210651 A1 | Aug 2012 | US |
Number | Date | Country | |
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61443830 | Feb 2011 | US |