AND

GEOPOLYMER FOAM ROOFING TILE

BACKGROUND OF THE INVENTION

Technical Field

[0001] The present invention relates generally to roofing materials and roofing systems. More particularly the present invention relates to roofing tiles fabricated from clay, ceramic, and/or concrete. Still more particularly, the present invention relates to a new thermal insulating material and system for thermally insulating conditioned spaces in commercial and residential building structures using a geopolymer foam and an AAC (aerated autoclaved concrete).

Background Art

[0002] Background Discussion: It has long been known to cover roof structures with sod and plant material. Throughout history roofs have been made with locally-sourced and readily available materials. The first known glazed clay roof tile was used in China 5,000 years ago. Greece and Babylon used flat earthenware roof tiles circ. 4,000 to 5,000 years ago. The Romans brought variations of the Greek clay tiles to England as early as 100 BCE.

[0003] Thatched roofs were developed around 735 CE. Wood shingles were introduced 300 years later. In an effort to prevent fires from spreading in England, King John (John Lackland) decreed a law in London that citizens must replace thatch and reed and wood roof coverings with clay tiles.

[0004] Despite the long history, industrial production of clay roofing tiles did not begin until the l9 ^th century. One hundred years later, concrete roof tiles were first used. In the early iteration (early l900’s), pigment was added to concrete tiles to make them resemble clay roofing tiles.

[0005] Asphalt also became available in the l9 ^th century. It quickly became a popular product due to low costs in mass manufacture.

[0006] Roofing technology has developed rapidly in the past 200 years. Even so, people generally still use the most readily available materials in their respective regions. Wood, clay, and metal are used for roof tiles in the southern part of North America, slate in the northeast, wood and metal in the Mid- and Northwest, and tile in the Southwestern area of North America. In the last 50 years, asphalt composition shingles have become nearly ubiquitous throughout North America.

[0007] Changes in the environment and in the economies of developing countries in the last 10 years have exposed significant deficiencies in conventional roofing systems and building materials and systems in general.

[0008] Some projections of per capita primary energy consumption indicate growth of as much as 40% in the next 20 years, due not only to the projected growth in human population, but the growth in populations with access to electric power. This will result in significant negative environmental impacts, largely due to increased carbon dioxide and other toxic emissions from fossil fuel consumption heat and electric power generation of heat and electrical power.

[0009] Thermal management of conditioned space buildings in the developing world represents one of the single largest sectors of global energy consumption. Therefore, the thermal efficiency of conditioned space buildings offers one of the largest opportunities to reduce the growth of the global carbon footprint. The use of thermally insulating materials constitutes the most effective way to increase efficiencies of these conditioned space buildings.

[0010] In the United States, changes in prescriptive building codes have mandated increased thermal insulation requirements in commercial and residential building envelopes. A significant change in the codes is the movement of the conditioned space envelope of a residential building from the floors, walls, and ceiling of a building, placing the envelope below the attic space of the roof; to the floors, walls, and roof perimeter of the building. Codes frequently require high thermal insulating barriers be employed at the roof perimeter, extending the conditioned space area into the attic spaces of residential buildings. A minimum range for a thermal resistance barrier, depending on climate zone variables and expressed in imperial R-values, is R-30 to R-50. That range is now required at least partially at the roof threshold of residential buildings, whereas it was never required previously.

[0011] The U.S. building industry currently has no conventional roofing system that contributes meaningfully to achieving these new insulating requirements. Furthermore, record losses from wildfires in the Western United States in the last three years, and hurricanes on the Gulf and Atlantic coasts in the last 10 years, have motivated calls for even more stringent and comprehensive fire and wind regulations for building and roofing material systems. Such catastrophic events reveal severe deficiencies in most extant conventional roofing systems.

[0012] Further, new building codes require placement of insulative materials on the outside of the building shell and outside the concrete foundation and block wall systems. No commercially available roof cladding today provides a significant insulative layer to the outside of the roof deck with direct exposure to the sun.

[0013] State of the Art: Asphalt composition shingle, cement tile, clay tile, metal, wood shingle and slate roofing represent the current state of the art in hi-slope roofing systems, the foregoing order corresponding to current market share.

[0014] Imperial R-values of conventional roofing materials include: (1) Asphalt variable. R-0.44 to R-0.88 (depending on material thickness and lap); (2) Cement and clay tiles R- 0.22 to 0.44 (depending on material thickness and lap); (3) Metal R-0.00; (4) Wood Shingles Variable. R-0.87 to R-1.07 (depending on material thickness and lap); (5) Slate ½" R- 0.05; (5) Imperial R-values (thermal resistance factors) of conventional roofing substrate materials, R- 1.06; and (6) 5/8" plywood and peel-n-stick R-1.27.

[0015] Fire Rating Classifications: Class A Roofing. To achieve a Class A rating, the roof must be effective against fire exposure and demonstrate the following performance characteristics: (1) it must experience maximum flame spread of 6 feet; (2) it must withstand a burning brand measuring 12" x 12" and weighing 2,000 grams; (3) it must resist ignition for 2 to 4 hours; and (4) it must resist 15 cycles of a gas flame turned on and off.

[0016] Common stand-alone Class A roof coverings include clay and concrete tiles, slate, and specially-treated asphalt glass fiber composition shingles. Assembly-rated Class A roof coverings are complete system assemblies that meet Class A standards when combined with other elements. For example, shake roofing with a fire-retardant treatment achieves a Class B rating standing alone, but it achieves a Class A rating when combined with specified underlayment materials, such as Type 72 roll roofing material.

[0017] Class B Roofing: Class B roofing is effective against fire exposure and demonstrates the following performance characteristics: (1) it experiences a maximum flame spread of 8 feet; (2) it withstands a burning brand measuring 6" by 6" and weighing 500 grams; (3) it resists ignition for 1 hour; (4) it resists eight cycles of a gas flame turned on and off

[0018] Pressure-treated shakes and shingles are the most common roofing materials to fall under the Class B rating.

[0019] Class C Roofing: Class C roofing provides only light fire protection. Roofing with a Class C rating is able to: (1) experience maximum flame spread of 13 feet; (2) withstand a burning brand measuring 1.5" x 1.5" and weighing ¼ gram; (3) resist ignition for 20 minutes; and (4) it resists three cycles of a gas flame turned on and off.

[0020] Examples of common Class C building materials include untreated wood shakes and shingles, plywood, and particleboard. The materials are not recommended for use in roof coverings.

[0021] It should be noted that a Class A fire rating is not a non-flammable rating. All three classes A, B and C are all based on the flammability _of the materials currently used in roofing systems.

[0022] Wind Ratings: The High-Velocity Hurricane Zones (HVHZ) are specifically defined as Miami-Dade and Broward Counties. As in previous editions of the Florida Building Code, a single wind speed is used for the HVHZ for each Risk Category Map. The design wind speeds in the HVHZ are as follows:

[0023] Miami-Dade County:

[0024] Risk Category I Buildings and Structures: 165 mph;

[0025] Risk Category II Buildings and Structures: 175 mph;

[0026] Risk Category III and IV Buildings & Structures: 185 mph.

[0027] Broward County:

[0028] Risk Category I Buildings and Structures: 156 mph;

[0029] Risk Category II Buildings and Structures: 170 mph;

[0030] Risk Category III and IV Buildings & Structures: 180 mph. [0031] Most modem roofs are rated to withstand 90 mile-per-hour winds, although there are roofing products available for hurricane and tomado-prone areas that can withstand winds up to 150 mph.

[0032] Impact test classification for roofing materials: FM 4473 is an industry standard test used for more rigid roofing materials such as clay, concrete, or slate. In the FM 4473 test, ice ball missiles are fired by a special launcher at a prepared roofing assembly. The test is intended to simulate the impact energy of a natural hail stone. Class ratings are given for impact resistance, Class 4 being the highest possible rating. Many of the rigid roofing materials perform at only Class 1 and 2 of this test.

[0033] See table, below:

The sizes of freezer ice balls in the standard correspond to the classes shown below:

Nom inal Ice Ball

[0034] Un-commercialized Known Art: Bellavia; U.S. Patent 9,038,330, issued May 26, 2015, teaches a lightweight, molded, polyurethane foam roofing tile having a spray-applied cementitious outer coating. The goal for the invention was to provide a roof tile with a thermal insulation benefit and a high wind up-lift rating. Another object was to provide a molded, wedge-shaped profile design in an individual tile to fill the void caused by overlapping tiles of an assembled roofing system to resist breakage of the low density foam tile body underfoot. Another objective was to provide a star-shaped recess on a bottom tile surface to facilitate adequate adhesion to the roofing substrate with adhesive foam.

[0035] The inherent weakness of Bellavia’ s concept was in the flammability and the instability of the polyurethane foam he employed, and in the fact that the assembled roof system would not pass ASTM El 08 fire testing without the use of a separate fire barrier underlayment. Furthermore, the instability of the polyurethane foam produced thermal expansion, resulting in the contraction and warping of the tiles, and thus contributing to the de-lamination of the sprayed cementitious coating and further exposing the foam to the elements, such as UV degradation and ultimately the failure of the roof as a system. Further still, the wedge-shaped design of the tile to augment the structural stability of the foam adds considerable complexity and expense to a manufacturing process.

Disclosure of Invention

[0036] It is a principal object of the present invention to provide an improved roofing product and roofing tile system with higher thermal insulating values than conventional roofing systems.

[0037] It is a further object of the present invention to provide a completely non flammable roofing product.

[0038] It is another object to provide a roofing system having higher wind up-lift resistance than conventional roofing systems.

[0039] It is another object of the present invention to provide a thicker, more substantial roofing tile that is no heavier than conventional clay, concrete, or slate roofing tile products.

[0040] Still another object of the present invention is to provide a composite roofing tile with high thermal insulating values.

[0041] Further, it is an object to provide a composite roofing tile that can be made in a plurality of textures, colors and having a general appearance emulating all the familiar, conventional roofing materials used today and throughout history.

[0042] The foregoing goals have been met in the present invention, which has a number of novel characteristics.

[0043] First, the present invention is a roofing tile unit having a core made from a binary, masonry composite structure of a non-flammable, lightweight ceramic, geopolymer and/or cementitious foam material. This material comprises a substantial portion of the core of the roof tile. The core is encased on at least 2 of its 6 outer surface sides with a molded, non flammable, lightweight, polymer reinforced cementitious mortar and/or a laminated composite layer of Portland cement based GFRC.

[0044] Second, the present invention is a masonry composite roof tile providing a single unit in a tile roofing system comprising a plurality of like units assembled over conventional roofing substrate in consecutive courses, one after and on top of the prior course with variable amounts of overlap, similar to the assembly of conventional concrete, and clay tile, slate, or wood shake shingle roofing systems. In an alternative installation, the masonry composite tiles of the present invention can be glued to the roof substrate and to prior tile courses with expanding, adhesive foam approved for use in roof systems such as Miami Dade approved AH160 adhesive foam or a similar adhesive.

[0045] Third, the present invention includes a masonry composite roof tile system in which individual tiles of the roof system may have a bottom surface, or at least one side of six outer surface sides, consisting of an open cell structure of porous masonry foam. The exposed surface optimizes surface area adhesion of the roof tile to the roofing substrate with the above-mentioned expanding, adhesive foam.

[0046] Fourth, the invention includes a masonry composite roof tile variably

manufactured with a molded and pigmented finish surface approximating the exterior surface textures of wood shingles, clay, concrete, and slate tile and metal surfaces on at least two of its six outer surface sides.

[0047] In all embodiments, the inventive roofing tile provides higher thermal insulation than covering materials employed in conventional roofing systems.

Brief Description of the Drawings

[0048] FIG. 1 is an upper perspective lower end view of a simplified embodiment of the cementitious and geopolymer foam roofing tile of the present invention, this embodiment having five of six of the sides of the cuboid shape finished with a molded, lightweight polymer reinforced cementitious coating and one side (viz., the bottom side) unfinished;

[0049] FIG. 2 is a lower perspective view thereof;

[0050] FIG. 3 is an upper perspective view of another embodiment of the invention, this having two of the six sides of the cuboid surface coated and finished with a molded lightweight polymer reinforced, cementitious surface;

[0051] FIG. 4 is a corresponding lower perspective view thereof;

[0052] FIG. 5 is an upper perspective view of yet another embodiment of the inventive composite roofing file, this embodiment having approximately half of the tile entirely unfinished with a ceramic coating and the other half coated on four sides;

[0053] FIG. 6 is a lower perspective view thereof; and

[0054] FIG. 7 is an upper perspective view showing a single course of roof tiles with interior tiles configured with a right and a left lap interface and end tiles configured with an interior lap interface. Best Mode for Carrying Out the Invention

[0055] FIGS. 1-2 illustrate an embodiment of the combination lightweight concrete and geopolymer foam composite roof tile of the present invention. FIGS. 3-4 illustrate a second embodiment. FIGS. 5-6 show a third embodiment. And FIG. 7 shows a single course of a further embodiment of the inventive roof tile of the present invention.

[0056] Referring first to FIGS. 1-2, there is shown an embodiment of the combination lightweight concrete and geopolymer foam composite roof tile 10 of the present invention. This embodiment is seen to be a six-sided low-profile elongate cuboid block 12 with a top side 14, right and left sides 16, 18, and first (lower) and second (upper) ends 20, 22, and a bottom side 24.

[0057] The tile core 26 (shown schematically as having amorphous particles and empty cell spaces) is fabricated from non-flammable, lightweight ceramic and or cementitious foam material that comprises the major portion of the tile volume. The cementitious foam material is encased on some or all of its various sides. In embodiments is it encased on at least two of its six outer surface sides with a molded, non-flammable, lightweight, polymer reinforced cementitious mortar 28 (shown schematically as having smooth surfaces). As will be appreciated, in this embodiment, only the bottom surface remains uncoated. All other surfaces are coated and encased.

[0058] FIGS. 3-4 show another embodiment, 40, identical in shape and composition with the above-described embodiment, but in this instance having only two of the six sides of the cuboid shape surface-coated and finished with a non-flammable, molded, lightweight, polymer reinforced cementitious mortar. The unfinished sides include the bottom side 42, the upper end 44, and the right and left sides 46, 48.

[0059] FIGS. 5-6 illustrate another embodiment 60, again identical with that of the first described embodiment, but with only half of the tile coated on any of its sides. Thus, it includes a lower half 62, coated on four of its sides, and an upper half 64 entirely uncoated.

[0060] FIG. 7 shows yet another embodiment, which includes interior roof tiles configured with a right and a left lap interface and end tiles configured with an interior lap interface having the molded finish on the exposed surfaces. Here there is shown a plurality of units constituting a linear course in a tile system 70. The linear course includes mid-course tiles 72, having right and left sides 74, 76, with an L-shaped lap interface, which provides an enhanced abutting tile joint, resists water penetration, and better resists heat transfer. Right and left end tiles 78, 80, include a single interior lap interface edge, 82, 84, respectively, and a flat outer edge 86, 88. In all embodiments, each tile of a course in the roof tile system of the present invention is configured to have a molded, finished surface on all of its visually and environmentally exposed surfaces.

[0061] A variety of systems having particular method steps can be employed for the fabrication of more specific variations of the general binary composite roof tile of the present invention. Examples of these systems and their method steps are outlined in the following descriptions. Figs.l - 7 are simplified examples of the present invention. Particular methods of tile fabrication are outlined in the following four tile fabrication systems for the inventive binary composite roof tile.

[0062] System 1 : In a first approach to tile fabrication, the following six fabrication steps apply.

[0063] Step 1) - The cementitious and/or geopolymer foam core of the binary composite is cut and milled to size from a larger cast stock of expanded masonry foam.

[0064] Step 2) - Separately, the molded outer shell of the binary composite roof tile is formed by spraying a particular formulation of cementitious mortar in a thickness of 3 to 9mm using a spray deposition system of the kind typically employed for GFRC face coat applications. The deposition is sprayed into a form to create a“negative” mold matching the finish surfaces of the roof tile and is sized to capture the foam body core. The same deposition can be applied to the opposing interface surfaces of the foam core.

[0065] Step 3) - The foam core is pressed into the mold and the applied face coat while the face coat material is still wet and workable.

[0066] Step 4) - The mold and the composite cast captured in the mold is then moved to an in-mold curing environment until an initial set of the cast is achieved.

[0067] Step 5) - After the initial set of the cast is complete, the mold and the composite cast are removed from the curing environment for removal. The product is then de-molded and produces a unified binary composite roof tile comprising a lightweight masonry foam core with a hard, molded outer masonry shell.

[0068] Step 6) - In a final step, the composite roof tile is returned to a curing

environment for final cure, and the mold is then recycled back into the production cycle.

[0069] System 2: In a second approach, the fabrication system involves the use of a plurality of injection mold cavities in an injection mold system. The following five steps apply. [0070] Step 1) - Providing injection mold cavities comprising an assembly of multiple parts having mold surfaces for the top or finish sides of the roof tile and opposing bottom or unfinished sides of the roof tile. The injection mold assembly is separated and/or broken down and configured to allow the deposition of a sprayed face coat 3 to 9mm thick to be applied to the internal parts of the mold. This will produce the finish mold surfaces of the roof tile.

[0071] Step 2) - The mold parts of the injection mold cavity with the applied face coat are coupled with their respective opposing un-coated cavity parts to provide a fully encapsulated mold cavity.

[0072] Step 3) - The fully assembled mold cavities are injected with the pre-expanded cementitious and/or geopoly meric foam to fill the remaining cavity of the mold that defines the tile body core; together with the encapsulated face coat provides the binary composite cast within.

[0073] Step 4) - A plurality of filled injection mold assemblies are moved either separately or together as multiple cavity units into an in-mold curing environment to achieve the initial set of the cure cycle. Alternatively, the injection mold assemblies can be equipped with heating elements to expedite the initial set time of the cure cycle and thus to expedite the de-molding of the cast products and recycling of the molds into the production cycle.

[0074] Step 5) - After the initial set in the cure cycle is complete, the molds are again broken down to release the cast product, and the unified binary composite is returned to a curing environment to complete the final cure. The molding system is reconfigured for continued production.

[0075] System 3: A third fabrication system involves fabricating contrasting elements of the binary composite separately and at least partially curing each element, then subsequently laminating the parts together. The cementitious and/or geopolymer foam that provides the body core is milled from a pre-cast foam block. Separately the hard, molded outer shell of the binary composite is a pre-cast composite of GFRC (glass fiber reinforced concrete) comprising a cementitious face coat and structural layers of glass fiber reinforced cementitious mortar. In this fabrication process, the following six steps apply.

[0076] Step 1) - The cementitious foam is cast and expanded into large millable cubes. It is then at least partially cured and then milled into slabs of a predetermined length, width, and thickness to fit and mate with a corresponding outer surface element produced with GFRC. [0077] Step 2) - Separately but concurrently with the first step, a GFRC production system is employed to produce the finish surfaces of the binary composite, wherein a mold of predetermined length and width to fit and mate with the foam slab production of Step 1 is configured. This will provide the finish surface top and sides and desired textures of the finish tile. The mold is sprayed or rolled with a cementitious face coat, followed with depositions of structural glass fiber reinforced cementitious mortar laminations typical of GFRC laminate systems to a combined thickness of 6 to l2mm thick. It is then cured in the mold until the initial set is achieved. Note: the GFRC face component mold, thus the cast face laminate, consists of a substantially planar slab with at least one side wall extending from the plan of the slab at 90 degrees on at least one of its 4 terminate boundaries providing the end and/or side profiles of the roof tile.

[0078] Step 3) - Once the initial set of the laminates cure is achieved, the GFRC finish face component is de-molded and (optionally) returned to the curing environment until ready for the lamination process in the next step.

[0079] Step 4) - The two components (i.e., the milled slab of cementitious foam and the cast GFRC finish shell) are configured to receive a deposition of expanding, adhesive glue to evenly coat the interface of the opposing components to be laminated together. The two components are then mated, pressed together, and glued side-to-glue side while the glue is still wet and malleable. Pressure is sustained to complete the bond between the two components before returning to a curing environment. Note: the expanding adhesive glue can be an adaptation of any one of the following material types: expanding geopolymer foam, expanding cementitious (Portland cement) paste, or expanding petro chemical and/or PU foam.

[0080] Step 5) - After the bonded composite slabs are adequately cured they are milled and cut into predetermined lengths and widths of the finished roofing tiles. Alternatively, the opposing components of the binary composite can be milled and cut to the finish roof tile sizes prior to lamination.

[0081] System 4: In still another, fourth system, a cementitious face coat material is applied topically to a cementitious and/or geopoly meric foam slab cut from a larger pre-cast stock, and the finished textures of a topically applied face coat is achieved with a screeded, tooled, rolled or pressed finish or a combination thereof. Five steps are involved.

[0082] Step 1) - This step involves producing and curing the pre-cast cementitious and/or geopolymeric foam into a cubic stock of a predetermined size suitable for the subsequent milling of a slab of a predetermined length, width and thickness, suitable for the following steps.

[0083] Step 2) - The milled slab is configured to receive a topically applied deposition of a cementitious face coat material uniformly covering the top and at least one side profile of the milled slab. The cementitious face coat paste can be applied with either a hopper and screed system, or a sprayed deposition, or a combination thereof.

[0084] Step 3) - After and/or in between multiple face coat depositions, face coat materials are either screeded, brushed, rolled, or pressed on at least two of the five exposed surfaces. After final deposition the finish face coat textures and colors are either tooled, rolled, sprayed or pressed or in combinations therein.

[0085] Step 4) - After face coat is finished, the coated slab is moved to a curing environment for the fished cure of the face coat material.

[0086] Step 5) - After the final cure is achieved, the coated slab is cut and milled to the finished dimensions of the roof tiles.

[0087] The above disclosure will enable one of ordinary skill in the art to practice the invention. The disclosure provides a disclosure of embodiments of the invention. However, the embodiments do not limit the invention to the exact construction, dimensional relationships, and operation shown and described. Modifications, alternative constructions, changes and equivalents will readily occur to those skilled in the art and may be employed, as suitable, without departing from the true spirit and scope of the invention.

[0088] Therefore, the above description and illustrations should not be construed as limiting the scope of the invention, which shall be defined by claims when and as filed in non-provisional patent application claiming the benefit of the filing date of the instant application.