Roof having improved base sheet using metal/fabric layers with overhangs

Abstract

A roofing panel includes an insulation board and a laminate of a metal layer and a fabric layer attached to the board. The board has a quadrilateral shape defining four edges and the laminate is attached to the board such that the laminate overhangs at least two of the edges of the board. A roof is formed from 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.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

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.

BACKGROUND OF THE INVENTION

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.

SUMMARY OF THE INVENTION

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.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a roofing panel in accordance with an embodiment of the present invention.

FIG. 2 is a sectional view taken along the lines 2-2 of FIG. 1.

FIG. 3 is a sectional view of an alternative embodiment of a roofing panel in accordance with the present invention.

FIG. 4 is a plan view of a roof employing a plurality of roofing panels in accordance with certain features of the present invention.

FIG. 5 is a plan view of a panel having different indicia for the location of fasteners.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring now to the drawings and, particularly, to FIGS. 1 and 2, there is shown an embodiment of a roofing panel 10 illustrating certain features of the present invention. The roofing panel 10 includes a laminate 12 of metal 14 and fabric 16. Preferably, the metal 14 is aluminum and may be 2 mils thick and the fabric 16 is a non-woven polyester having a weight ranging from 4 to 14 ounces per square yard. A polyester sheet having satisfactory properties is one made by the Johns Manville Company, South Carolina and sold under the trade name of Trivera®. A suitable aluminum/polyester laminate is Polaralume®, marketed by Palisades Atlantic inc., Ridgefield Park, N.J.

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 FIGS. 1 and 2, or with the fabric side 16 down, as shown in FIG. 3. In either case, when the panels 10 are applied to a roofing deck, the laminate will overlap the preceding side.

Referring now to FIG. 4, there is shown an embodiment of a roof 20 illustrating certain features of the present invention. The roof 20 includes a plurality of roofing panels 10 which are attached to a roof deck 22 such that an overhanging side e.g. 12a or 12b of a panel 10 overlaps the non-overhanging side 12c or 12d of an adjacent panel 10. The deck 22 may be made of metal, wood, concrete, gypsum or any other conventional deck material.

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 FIG. 5, there is shown a plan view of a base sheet panel 10 having a plurality of different types of indicia thereon, such as crosses (+), triangles (Δ) and circles (∘). Each different type of indicia represents a given FM wind number and the location of each on the base sheet represents the location in which a fastener should be inserted to achieve such FM number. In the example shown in FIG. 5, the crosses (+) represent 90 PSF, the triangles (Δ) 120 PSF and the circles (∘) 150 PSF. It will be noted that the spacing between the crosses (+) are greater than the spacing between the triangles (Δ) which in turn are greater than the spacing between the circles (∘). That is, the spacing between indicia representing a lower FM psi number is greater than the spacing between indicia representing a higher FM number because the lower the FM number the less the number of fasteners required and the greater the spacing therebetween.

It should now be appreciated that the present invention provides a number of advantages as compared to prior art roofs:

• • 1. It prevents gassing of the insulating board when using urethane, isocyanurate or any foam that utilizes gas in the cell. It is well known in the industry that isocyanurate insulation releases gas from the topside when hot coal tar or hot asphalt is applied. This gassing causes blistering and delamination of the roofing membrane and normally as recommended by NRCA requires a board overly. The panels 10, do not requires a board overlay and thus eliminate the cost of the labor and cost of the board overlay.
  • 2. The panels 10 prevent hot molten tar or asphalt flowing between the joints of the insulation board 18 protecting occupants from serious burns. In the case of new construction, it prevents inside workers from being burned by dripping hot tar or asphalt.
  • 3. The composite laminate 10 of polyester and aluminum enables the insulation to be secured to the deck utilizing 50% less fasteners then insulating boards void of the composite. For example, if insulation boards 18 void of the composite were installed approximately 36 fasteners would be utilized per 100 sq. ft. to obtain a 90 PSF rating. This wind lift rating is required to be in compliance with all building codes in the United States. This reduction in fasteners means less holes in the deck, 50% less fasteners plus 50% less labor for the installation.
  • 4. Insulation boards 18 for roofing tend to be brittle. The lamination 12 of the composite reduces breakage during shipping and installation resulting in lower costs.
  • 5. The laminated composite 12 adds dimensional strength to the insulation board 18. It is well known in the industry that roofing insulation, especially foam type insulation lacks dimensional stability.
  • 6. When attaching fasteners through insulation, it is necessary that all fasteners are installed at the top of metal decking, i.e., in order to pass Factory Mutual or Global or UL uplift regulations and to comply with test listings, all fasteners must be the top of metal decking. When using a roll, it is virtually impossible to locate the top of a corrugated steel decking. It is relatively, easy to do so, however, when using the panels 10.
  • 7. When the composite 12 is laminated to the insulation board 18 at the factory to form the panels, the task of installation is made easier as the individual boards are laid individually and fastened. In contrast, in the loose laid method, the wind is a negative factor, blowing unfastened insulation and causing work stoppage and damage to insulation boards.
  • 8. The two most notable testing agents are Factory Mutual Global and UL Labs. These agencies are an important function in testing all kinds of roofing membranes and insulation. The tests conducted that are of extreme importance are wind uplift, interior fire, hail damage and weather ability. Panels in accordance with the invention perform exceptionally well on these tests.
  • 9. Tests have proven that the panels will achieve 150 PSI which means it will withstand winds of 160 MPH to 170 PH. The calorimeter test tests a roof membranes' resistance to interior fire, the aluminum laminate prevents the asphalt or tar that melts and flows from entering the building and spreading interior fire, the non-woven polyester has extreme toughness that resists puncturing the membrane from hail stones.
  • 10. The aluminum 14 also acts as a vapor retarder, preventing interior moisture in the form of vapor, from entering under and into the roof membrane which can cause blistering.
  • 11. Since the laminated composite 12 laps the joints of the adlacent foam boards 18, it prevents asphalt from flowing through the joints and into the building feeding the fire from within.
  • 12. The covering of the seams of the insulation boards 18 prevents ridging of the roof covering, as well as allows the installation to pass interior UL and FM interior fire test (Calorimeter).
  • 13. If the composite is installed with the aluminum side 14 up, a superior facing is created on which to install a self-adhering roof membrane

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.

Claims

1. A roofing panel comprising:

an insulation board having a quadrilateral shape defining four edges; and

a laminate of a metal layer and a fabric layer attached to said board such that said laminate overhangs at least two of the edges of said boardfabric layer faces said deck.

2. The roofing panel of claim 1, wherein the fabric of said fabric layer is made of plastic.

3. The roofing panel of claim 2, wherein said plastic is non-woven polyester.

4. The roofing panel of claim 1, wherein the metal of said metal layer is aluminum.

5. The roofing panel of claim 1, wherein the metal layer is aluminum and the fabric layer is non-woven polyester.

6. The roofing panel of claim 1, wherein the laminate is attached to the board with the metal layer in contact with the board.

7. The roofing panel of claim 1, wherein the laminate is attached to the board with the fabric layer in contact with the board.

8. A roof comprising a plurality of roofing panels, each of the roofing panels comprising an insulation board having a quadrilateral shape defining four edges and a laminate of a metal layer and a fabric layer attached to said board such that said laminate overhangs two of the edges of said board, thereby forming a roofing panel having two overhanging edges and two non- overhanging edges, the roofing panels being interconnected with one another such that an overhanging edge of one roofing panel overlies a non-overhanging edge of an adjacent roofing panel.

9. The roof of claim 8, wherein the fabric of said fabric layer is made of plastic.

10. The roof of claim 9, wherein said plastic is non-woven polyester.

11. The roof of claim 8, wherein the metal of said metal layer is aluminum.

12. The roof of claim 8, wherein the metal layer is aluminum and the fabric layer is non-woven polyester.

13. The roof of claim 8, wherein the laminate is attached to the board with the metal layer in contact with the board.

14. The roof of claim 8, wherein the laminate is attached to the board with the fabric layer in contact with the board.

15. A method of forming a roof on a deck comprising:

placing a plurality of roofing panels over said deck, each of the roofing panels comprising an insulation board having a quadrilateral shape defining four edges and a laminate of a metal layer and a fabric layer attached to said board such that said laminate overhangs two of the edges of said board, thereby forming a roofing panel having two overhanging edges and two non- overhanging edges, the roofing panels being interconnected with one another such that an overhanging edge of one roofing panel overlies a non-overhanging edge of an adjacent roofing panel. an insulating layer over said deck; and

fastening said panels to said deck.

16. The method of claim 15, wherein the fabric of said fabric layer is made of plastic.

17. The method of claim 16, wherein said plastic is non-woven polyester.

18. The method of claim 15, wherein the metal of said metal layer is aluminum.

19. The method of claim 15, wherein the metal layer is aluminum and the fabric layer is non-woven polyester.

20. The method of claim 15, wherein the laminate is attached to the board with the metal layer in contact with the board.

21. The method of claim 15, wherein the laminate is attached to the board with the fabric layer in contact with the board.

22. The method of claim 15, further comprising applying a built-up roof composite over said laminate.

23. The method of claim 15, further comprising applying a single-ply membrane over said laminate.

24. The method of claim 15, wherein the layer of each panel on the side facing away from the deck has a plurality of different types of indicia, each type of indicia representing a different wind uplift prevention, and wherein the step of fastening said panels to said deck includes inserting fasteners through said panels at locations corresponding to the location of the types of indicia representing a desired wind uplift prevention.