Patent Application
20050144850
The present invention relates generally to roofs and, more particularly, to a metal/fabric laminated roofing panel and to roofs made using the same.
Although the present invention is applicable to any type of roof, it has particular applicability in connection with its use in built-up and single ply roofs.
Built-up roofs are formed of alternate layers of bituminous material and felt which are assembled or “built-up” in the field. The alternate layers of bituminous material and felt are assembled onto a base sheet which overlies an insulation layer. The insulation layer and base sheet are attached to a roof deck which typically is made of metal, wood, concrete gypsum or any other conventional deck material.
The term “built-up roof composite” as used herein means any one of a plurality of different conventional built-up roof composites used on the top of base sheets, such as the built-up roof composite described herein, as well as others, such as EPDM, PVC, modified bitumen, coal tar and Hypolon.
The bituminous material is usually of coal tar or asphalt origin and is applied by hot-mopping between alternate layers of the felt.
The primary function of the base sheet is to prevent blistering of overlying layers. Additionally, the base sheet prevents the bituminous material from dripping into and through the deck. Such penetration has a number of disadvantages. First, any dripping during installation can penetrate into the underlying building, thereby causing injury to people and damage to equipment, furnishings, etc. Additionally, dripping, in the case where the underlying deck is made of wood, could also serve to attach the insulation layer to the deck by means of the bituminous material, as well as the mechanical fasteners, thereby making removal of the insulation layer difficult in those situations where it is necessary to replace the roof. Further, the overlay prevents any of the overlying bitumen from passing through the deck and into any interior fire, thereby preventing any further fueling of the fire.
An alternative structure to the built-up roof is a weather resistant elasto-plastic membrane which may comprise, for example reinforced polyvinyl floride, butyl rubber, vinylidene chlorides and fluorides, polyesters, polyvinyl chloride, neoprene, chlorosulfonated polyethylene, polysulfides, polyurethanes, polyepoxies, acrylates, and other materials having suitable mechanical strength and weather durability. Such structures are generally designated “single-ply roofs” because a single thickness of the weather-resistant membrane is generally sufficient, as compared with the plurality of layers of roofing felt generally required for built-up roofs. In addition to the membrane, a layer of insulating material is also generally provided between the membrane and the roof deck of the structure in single-ply roofs.
The term “roof covering” as used herein means either a built-up roof composite or a single ply membrane.
An improved base sheet which provides superior fire resistance and wind uplift prevention compared to prior art base sheets is disclosed in U.S. Pat. Nos. 6,108,993 and 5,884,446, the entire disclosures of which are incorporated herein by reference. As disclosed in U.S. Pat. Nos. 6,108,993 and 5,884,446, the base sheet includes a laminate comprised of metal, such as aluminum, and a fabric, such as non-woven polyester.
In the case of a built-up roof, the metal layer serves as a fire barrier to prevent bitumen entering the underlying building and fueling a fire. Additionally, the metal layer acts as a barrier for preventing any bitumen (or other material) applied during installation from penetrating the deck and into the interior of the underlying building. Additionally, the metal layer, in the case of wood decks, prevents the roof from being adhesively attached to the deck since such adhesion could make roof replacement very costly and, in some cases, impossible.
Additionally, a roof using the base sheet of U.S. Pat. Nos. 6,108,993 and 5,884,446 requires fewer mechanical fasteners to achieve superior wind uplift prevention. Less fasteners results in a substantial reduction in material and installation costs.
The metal layer also acts as a barrier to moisture vapor resulting from high humidity conditions in the underlying building. Moisture vapor passing into a roof could cause blistering, cracking and distortion of the roof. The metal layer prevents such moisture from reaching any of the overlying layers. In order to prevent the moisture vapor trapped by the metal vapor barrier from being trapped in the insulation layer and causing damage or lack of effectiveness thereof, it is necessary to vent such moisture vapor.
To this end, in accordance with one aspect of the invention disclosed in U.S. Pat. Nos. 6,108,993 and 5,884,446, the metal layer has embossments thereon which form channels to the edge of the roof, thereby venting any entrapped vapors.
The present invention is directed to a roofing panel employing the base sheet disclosed in U.S. Pat. Nos. 6,108,993 and 5,884,446.
In accordance with an embodiment of the invention, the roofing panel includes an insulation board having a quadrilateral shape defining four edges and a laminate of a metal layer and a fabric layer attached to the board such that the laminate overhangs at least two of the edges of the board.
In accordance with another embodiment of the invention, a roof comprises a plurality of the roofing panels which are interconnected with one another such that an overhanging edge of one roofing panel overlies a non-overhanging edge of an adjacent roofing panel.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
Referring now to the drawings and, particularly, to
The laminate 12 is attached to a roofing insulation board 18 of any size such that at least two sides, e.g. 12a and 12b, overhang the board 18 with the other sides 12c and 12d cut even to the insulating board 18. The laminate 12 may be attached to the board 18 with the aluminum side 14 down, as shown in
Referring now to
The panels 10 are attached to the deck 22 by suitable mechanical fasteners 24, such as screws or nails, which are inserted through respective metal plates (not shown). In accordance with the present invention, fewer such fasteners are necessary to attach the panels 10 to the metal deck 22 to achieve a given wind-up lift prevention as compared to prior art built-up roofs not using panels or the base sheet disclosed in U.S. Pat. Nos. 6,108,993 and 5,884,446.
Over the overlapping panels 10 a conventional roof covering 26 which may be either a built-up roof composite or a single ply membrane is formed.
Typically, as discussed above, built-up roof composites are formed of alternate layers of bituminous material and felt. The felts may be fiberglass or may be organic felt, such as asphalt saturated felt or, as disclosed in U.S. Pat. Nos. 4,521,478, 4,599,258 and 4,837,095, the entire disclosures of which are incorporated by reference, the built-up roof composite may be formed of alternate layers of a non-woven polyester and bituminous material. Typically, the bituminous material is usually of coal tar or asphalt origin and is applied by hot-mopping. The metal layer 14 acts as a barrier to prevent the bituminous material from penetrating down to the underlying insulation board 18.
One of the problems with built-up roofs employing bituminous materials is that when there is an internal fire in the building, the temperatures can be such as to cause the bituminous material to liquify and penetrate through the deck into the interior, thereby feeding the fire and causing greater fire damage, as well as greater hazard to fire personnel involved in fighting the fire. Accordingly, it is necessary to provide a barrier to such bituminous liquid from entering the building. In prior art built-up roofs, the half-inch fiber board is intended to prevent the overlying bituminous material from passing through the base sheet and entering the building. However, the size and weight of the fiber board precludes the board from being laid down as one continuous sheet. Instead, the fiber board is in the form of plurality of blocks of relatively easy to handle dimensions which are laid down side by side with seams between adjacent blocks. As a result, there is a possibility of bituminous liquid entering the building through such seams.
Because the panels 10 overlap there are no seams in a roof 20 formed using the panels 10. Accordingly, any liquid bituminous material is prevented from passing through to any of the underlying layers. Thus, the present invention provides superior fire safety features as compared to the prior art.
When the roof covering is a single ply membrane, such membrane preferably comprises an elasto/polymeric material. Without limitation on the generality of useful materials, the membrane may be formed of ethylene propylene diene monomer (EPDM), modified bitumen (MB), reinforced modified bitumen (MB/R), polychloroprene or neoprene (NEO), polyvinyl chloride (PVC), chlorinated polyethylene (CPE), polyisobutylene (PIB), or ethylene-copolymer-bitumen and anthracite microdust (ECB). The adhesive is chosen for its compatibility with the material comprising the membrane.
The number of fasteners employed in securing the base sheet to an underlying deck is a function of the hold down force required to achieve a given wind uplift prevention. Factory Mutual (“FM”), an independent testing agency, in addition to testing roofs for certain fire prevention criteria, also tests roofs to determine whether they have a desired wind uplift prevention. The tests employed by FM are designated with a particular PSF (pounds per square foot) number (“FM number”). Most roofs which are required to pass an FM wind uplift prevention test are required to achieve an FM number of 90 PSF. Additional wind uplift capabilities are tested for in increments of 30 PSF (e.g., 120 PSF, 150 PSF, etc.).
There is no predetermined criteria for determining either the number of fasteners or the spacing therebetween required to achieve a particular wind uplift prevention. Accordingly, the number of and spacing between fasteners will vary from installation to installation and, in most cases, will have no correlation to an FM number.
In accordance with one aspect of the present invention, the locations of the fasteners for each FM number (e.g., 90 PSF, 120 PSF, etc.) are predetermined by, for example, empirical methods. Then, indicia representing the empirically determined locations to achieve each FM number are marked on the top surface of the base sheet.
More specifically, referring to
It should now be appreciated that the present invention provides a number of advantages as compared to prior art roofs:
The present invention thus provides a system that substantially reduces catastrophic damage resulting from both wind and fire and does so at reduced costs.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. For example, the metal layer of the panel may have embossments to provide venting, as disclosed in U.S. Pat. Nos. 6,108,993 and 5,884,446. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
This application is based on and claims priority to Provisional Application Ser. No. 60/529,379, filed Dec. 11, 2003 and entitled “ROOFING PANELS HAVING METAL/FABRIC LAYER LAMINATED TO INSULATION BOARD WITH OVERHANGS,” the entire disclosure of which is incorporated hereby by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60529379 | Dec 2003 | US |
