EP1009893A1

EP1009893A1 - Method and apparatus for roof covering

Info

Publication number: EP1009893A1
Application number: EP98905097A
Authority: EP
Inventors: Joseph Graham; Keith Kennedy; Vincent Meyer
Original assignee: Minnesota Mining and Manufacturing Co
Current assignee: 3M Co
Priority date: 1997-02-18
Filing date: 1998-02-17
Publication date: 2000-06-21
Also published as: AU6279898A; CA2283857A1; WO1998036139A1

Abstract

A method and apparatus for adhering external roof coverings (e.g., flat roofing membranes, shingles, etc.) to a roof deck using mechanical fateners, such as hook and loop fastener structures. One part (16) of a low-profile hook and loop fastener is secured to the roof deck, desirably by means of being on one side of a water-impervious sheet (18) having pressure sensitive adhesive on its other side. The pressure sensitive adhesive is used for adhering the sheet to the roof deck (10). A flat roofing membrane or individual shingel (20) components have the second complementatry part (22) of the mechanical fatener on a back surface thereof an positioned for engagement with the first part of the hook and loop fasterner on the roof deck.

Description

METHOD AND APPARATUS FOR ROOF COVERING

FIELD OF THE INVENTION

The present invention relates to roof covering assemblies and a method for covering a roof. More particularly, the present invention relates to a roof covering which is detachably engaged with the roof deck. Even more particularly, the present invention relates to detachably securing flat and shingle roof coverings to a roof using a hook and loop fastener.

BACKGROUND OF THE INVENTION o Ever since mankind emerged from the cave, the construction of adequate and durable shelter has been a significant issue. In the course of shelter development (e.g., from straw house to stick house to brick house), a foremost concern has been the search for an inexpensive, durable and waterproof roofing material. While in some environments, a thatched or sod roof may be suitable, in most, it is not. Over s the years, various materials have been employed as the external covering material for roofs, including slate, wood (e.g., shake shingles), clay tile, metal sheets, asbestos-based materials, asphalt-based materials and plastic materials. These roofing materials have been used in the form of shingles and/or flat roofing. One currently available asphalt- based shingle material is a three-tab asphalt shingle. Each three-tab shingle is c approximately one foot high by three foot wide, and is twice slotted along its bottom edge to form three tabs along its lower half which, upon assembly with other shingles to form a roof covering, are the only portions of the shingle which remain visible. An asphalt three-tab shingle bears backing sand or other granular materials (e.g., mica) on its back surface and facing granules on its front surface. The granular material on the back surface of the shingle provides weight to the shingle and acts as a blocking material to keep the shingles from sticking together when bundled for shipping and storage. On the visible tabs of the shingle, the facing granules may be of any desired color for aesthetic purposes. Another type of asphalt-based shingle is referred to as a laminated shingle, which is constructed and applied to a roof similarly to a three-tab shingle, but v has a multi-ply shingle construction and may not have tabs formed therein.

While a structure's roof may serve to block the sun and wind from its interior, the roofs primary purpose is to serve as a moisture barrier. However, for most conventional shingle roof covering materials (and specifically for three-tab or laminated asphalt shingles and flat roofing), the attachment of the external roof covering can require the use of nails or staples driven through each shingle and the underlying roof deck Thus, any moisture barrier provided by the roof deck or the shingle itself is violated by the use of such fasteners In some jurisdictions, building code requirements may dictate that an underlying layer of roofing felt (an asphalt-saturated felt material) be laid over the roof deck (typically a wooden roof deck) prior to application of the shingles The roofing felt is required only for the initial few feet of a roof line, or may be required over the entire roof deck In cold weather climates, roofing felt may serve as an initial moisture barrier below the three-tab asphalt shingles, and specifically adjacent the lower portion of the roof line where ice dams may fonn which can cause water to seep under and upwardly on a roof through the shingles to the roof deck In some jurisdictions, an ice dam material (e g , a heavy felt layer adhered to the roof deck) may also be required for up to the first six feet of the roof deck The use of staples or nails to secure the shingles to the roof deck also penetrates any underlying roofing felt or ice dam material, thus compromising their ability to serve as moisture barriers In addition, nails and staples are a rather permanent form of attachment Once secured by such fasteners, a shingle may not be easily realigned or replaced

Another localized concern for roofing materials relates to durability in high wind conditions Three-tab asphalt shingles are laid in overlapping courses so that the tabs at the bottom portion of each shingle are the only parts of that shingle which are visible once a roof covering assembly has been constructed Each shingle is formed with a strip of seal-down asphalt on its front surface above its tabs (in the upper "head-lap" area of the shingle) In order to hold or seal down the tabs when the wind is blowing, the shingles are arranged so that the seal-down strip of asphalt on the shingles of one course is covered by the ends of the tabs of the shingles of the next course As the assembled roof is exposed to heat (via the sun) in excess of 160° F (71 1° C ), the seal- down strip of asphalt softens and "flows" onto the back surface of the overlying shingle tab above it to bond that tab to the course of shingles below Such bonding is particularly important where high winds are likely, in order to minimize roof damage and costs from storms such as hurricanes, tornados, and/or straight-line wind storms These storms often damage not only the roof covering assembly itself, but also cause water to be driven up under the shingles, causing water damage that can result from the roof moisture barrier integrity being compromised dunng such a storm With respect to asphalt shingle construction, some jurisdictions with high wind considerations also require that the shingle be of a certain weight, in order to further minimize its being peeled off the roof by such winds Shingle constructions which fold over to mechanically interlock adjacent shingle courses have been proposed, but such shingles must still be nailed or stapled to the roof deck

Flat roofing typically uses of ethylene propylene diene monomer (EPDM) or polyvinyl chloride (PVC) sheets or membranes of 10-50 ft (3-15 m) widths In most cases there is an underlayment of an insulation board placed on top of the roof and under the membrane These are typically held down periodically with lag bolts and large washers The membrane is laid over the roof surface and the large sheets are spliced and sealed at the seams to create one continuos sheet of impervious (to water) membrane the size of the entire roof A flat roofing membrane must also be firmly attached to the roof because wind blowing across a flat roof causes a lifting force that can actually cause the membrane to balloon, eventually stretching out the membrane to the point of causing failure The membrane is normally attached to the roof in one of three ways to prevent lifting s Rocks have been placed on top of flat roofing membranes to hold down the membrane Rocks are cheap but they are heavy and put additional strain on the roof They can also be difficult to hoist to the top of buildings and can be difficult to obtain in big cities Also, in high winds there is the potential for the rocks to blow off the roof and cause damage to surrounding buildings, people, cars, 0 etc A layer of liquid adhesive placed between the Insulation board and roofing membrane has also been used to adhere the membrane in place However, EPDM and PVC can be difficult materials to adhere, typically requiring the use of aggressive liquid adhesives Such liquid adhesives are difficult to work with and most emit environmentally unfriendly volatile organic compounds (VOCs) D Alternative water based adhesives have trouble giving good adhesion to EPDM and PVC and can take a longer time to dry This delay in drying can result in failures if the lifting force of a wind is sufficient to separates the membrane from the adhesive before it is fully dried Flat roofing membranes have also been held down using strips of metal placed on top of the membrane at spaced intervals and lag bolted o through the membrane to the roof The holes formed in the membrane for the lag bolts have to be sealed and can form cites for water intrusion through the membrane, thereby reducing the useful life of the flat roofing long before the membrane material has lost its moisture resistance In addition, the membrane can still lift and stretch in between the metal strips Therefore, there is a need for an improved roofing cover system that avoids at least some or all of the problems associated with roof covering systems used in the past

SUMMARY OF THE INVENTION The above need is satisfied by providing a roof covering assembly according to the present invention in which a roof covering is detachably securable to a roof by the use of a hook and loop fastener system

In one aspect of the present invention, a roof covering assembly is provided which comprises a first and second complementary part of a hook and loop fastener and a roof covering The first part of the hook and loop fastener is securable onto a portion of a roof deck The roof covering is disposable over the roof deck, and the second complementary part of the hook and loop fastener is secured on a portion of the back surface of the roof covering The roof covering is detachably engagable with the roof deck via the hook and loop fastener after the first part of the hook and loop fastener is secured onto the roof deck In a one embodiment, the first part of the hook and loop fastener is defined by a hook-engaging material and the second part of the hook and loop fastener is defined by a plurality of outwardly projecting hooking stems formed to releasably engage the hook engaging material upon contact therewith It is desirable for the first part of the hook and loop fastener to be borne by a flexible, water-impervious substrate sheet

The roof covering can include a flat roof covering comprising a membrane having the second complementary part of the hook and loop fastener secured on a portion of the back surface thereof, wherein the membrane is detachably engagable with the roof deck via the hook and loop fastener after the first part of the hook and loop fastener is secured onto the roof deck It may be desirable for the second complementary part to be a nonwoven material The roof covering can also comprise one or more shingles suitable for being disposed over the roof deck in overlapping courses The back surface of each shingle has the second complementary part of the hook and loop fastener secured on a portion thereof, wherein each of the shingles is detachably engagable with the roof deck via the hook and loop fastener after the first part of the hook and loop fastener is secured onto the roof deck

The roof covering may also comprise a combination of a flat roof covering and one or more shingles In addition, the roof covering assembly of the present invention can include the roof deck

In another aspect of the present invention, a method is provided for covering a roof deck with a roof covering The method comprises the steps of affixing a first part of a hook and loop fastener onto the roof deck, aligning a roof covering over the roof deck, the roof covering material having a second complementary part of the hook and loop fastener on a portion of the back surface thereof, and urging the roof covering against the roof deck with force sufficient to detachably engage the first and second parts of the hook and loop fastener together for holding the roof covering onto the roof deck In a one embodiment, the affixing step includes covering at least a portion of the roof deck with a layer of water-impervious material

When the roof covering includes the above flat roof covering, the step of aligning comprises aligning the membrane over the roof deck, and the step of urging comprises urging the membrane against the roof deck with force sufficient to detachably engage the first and second parts of the hook and loop fastener together for holding the membrane onto the roof deck When the roof covering includes a plurality of the above shingles, the step of aligning comprises aligning a first or more rows of the shingles over the roof deck, and the step of urging comprises urging the shingles against the roof deck with force sufficient to detachably engage the first and second parts of the hook and loop fastener together for holding the shingles onto the roof deck

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further explained with reference to the attached figures, wherein like structures are referred to by like numerals throughout the several views

FIGS 1A and IB are isometric partial views of a roof deck showing two stages of its covering with the roof covering assembly of the present invention,

FIG 2 is a top plan view of a three-tab shingle of the present invention,

FIG 3 is a bottom plan view of a three-tab shingle of the present invention,

FIG 4 is sectional view as taken laterally through a roof deck showing the inventive roof covering assembly in generated form for clarity,

FIG 5 is an enlarged sectional view showing the opposed parts of the hook and loop fastener in engaged relation,

FIGS 6A and 6B are isometric partial views of a roof deck showing two stages of its covering with an alternative embodiment of the roof covering assembly of the present invention;

FIG. 7 is a sectional view taken laterally through a roof deck showing an alternative embodiment of the inventive roof covering assembly in generated form for clarity; and

FIG. 8 is an enlarged sectional view showing the opposed parts of an alternative hook and loop fastener in engaged relation.

While the above-identified drawings features set forth several embodiments, other embodiments of the present invention are also contemplated, as noted in the discussion. This disclosure presents illustrative embodiments of the present invention by way of representation and not limitation. Numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention.

DETAILED DESCRIPTION OF EMBODIMENTS

In modern structure construction, roof lines are usually sloped to facilitate water run off. As illustrated in FIGS. 1A and IB, a roof deck 10 is supported above walls 12. The roof deck 10 presents a generally planar sloped surface for supporting a roof covering assembly to provide protection for the structure from the elements. The roof deck 10 may be formed from any suitable construction material, such as concrete, metal or wood. For a typical dwelling structure construction, the roof deck 10 is formed from plywood sheets supported by an underlying roof frame or truss structure (not shown).

In FIG. IN the roof deck 10 has its top surface 14 covered by a first part 16 of a hook and loop fastener structure. The first part 16 is borne by a flexible vapor barrier sheet 18 which is secured to the roof deck. It is desirable for the sheets 18 to be laid edge to edge or slightly overlapping to provide a secure vapor barrier over the entire roof deck 10. As seen in FIG. IB, a plurality of shingles 20 are laid in overlapping rows or courses over the roof deck 10. The first course of shingles 20 is laid along the lowermost edge of the roof deck 10, and subsequent courses are overlaid on each other as the roof covering is advanced up the roof deck 10. A second complementary part 22 (FIG. 3) of a hook and loop fastener is secured on a back surface of each shingle 20. The second part 22 engages the first part 16 on the roof deck to secure each shingle 20 to the roof deck. In a desired embodiment, the first part 16 of the hook and loop fastener is the loop portion which presents for engagement a surface having multiple exposed fiber loops It is desirable for the second part 22 to include a plurality of hooking stems formed and disposed to engage the fiber loops of the loop portion of the first part 16, in typical hook and loop fastener fashion As used herein, "hook and loop fastener" means any two-part mechanical fastener which operates on contact or pressure to mechanically engage two components A typical example of a hook and loop fastener using fibers and hooking stems is the Velcro®-type mechanical fastener Other suitable mechanical fastener assemblies will also suffice, as discussed below, so long as they achieve the characteristic of mechanical engageability and separability without damage to the parts being joined and separated, and provide sufficient engagement force

The application of the invention is illustrated herein via a typical three- tab asphalt shingle construction However, the invention is equally applicable to other shingle types (e g , laminated shingles) and other shingle materials (e g , wood, plastic, etc ), and the discussion using three-tab shingles is intended to be illustrative, not limiting, in this regard

As seen in FIG IB, each row or course of shingles is formed from a plurality of three-tab shingles FIGS 2 and 3 illustrate a three-tab shingle 20 embodying the present invention Each shingle 20 has a bottom edge 24, a top edge 26 and side edges 28 and 30 Each shingle has a head lap or upper header portion 32 and a butt part or lower tab portion 34 A pair of slots or cut-outs 36 extend from the bottom edge 24 through the lower tab portion 34 to define three shingle tabs 38

Each shingle 20 is formed from an underlying flexible substrate material (typically fiberglass or organic paper) which bears a coating of asphalt on each major surface thereof The asphalt coatings in turn each bear a particle or sand layer embedded thereon A front surface 39 of the shingle 20 is illustrated in FIG 2, and has its entire surface covered with granule, except for a longitudinally extending strip of exposed seal-down asphalt 40 This strip 40 extends generally across the shingle's length, along the juncture of the header and tab portions 32 and 34 After assembly, the only visible portions of the shingle 20 will be the tabs 38 Thus, the prime granule borne on the front surface 39 of each tab 38 may be any desired color or pattern to achieve a particular appearance for the roof covering

On its back surface 41 (FIG 3), each shingle 20 also has its asphalt layer covered with a granular material (e g , backing sand or mica) Desirably, the only portions of the back surface 41 of the shingle 20 not covered by a granular backing material would be those portions bearing the second part 22 of the hook and loop fastener. In a desired embodiment, a minor section of the upper header portion 32 bears the second parts 22 of the hook and loop fastener. A section of second part 22 is adhered directly to the asphalt layer on the back surface 41 of the shingle adjacent each edge 28 and 30, and above each slot 36. During construction of a shingle 20, the asphalt coating is applied in molten form, and the second part 22 may be bonded thereto by setting it into the molten asphalt coating. While the asphalt coating is still soft, the granular backing material is applied, which embeds and adheres to the asphalt coating everywhere but where the second part 22 sections have been laid. As illustrated in FIG. 3, four second part sections 22 are provided for each shingle, adjacent its top edge 26. These take the place of mechanical fasteners (nails or staples) and in a desired embodiment, the central second part sections 22a are two-inch by two-inch sections, while the edge second part sections 22b are one-inch by two-inch sections. FIG. 4 illustrates the orientation of the components during sequential assembly of a roof covering of the present invention. The sheet 18 is adhered to the top surface 14 of the roof deck 10 by suitable means, such as a pressure sensitive adhesive. The sheets 18 are laid edge to edge or slightly overlapping, and the sheet material is a water-impervious material, thereby forming a vapor barrier across the roof deck 10. It is desirable for the sheet 18 to be formed from 3M product XML-5008 (Knitted Loop Tape), available from Minnesota Mining and Manufacturing Company, Saint Paul, Minnesota. This material has a polyolefin film backing or substrate with pressure sensitive adhesive on one side, and a warp-knitted polyester fabric bonded on its other side. This relatively thin material is available in roll form (without a liner) and can simply be unrolled and adhered on a roof deck by its pressure sensitive adhesive. A desirable width for the roll material is about 36 inches. The sheet 18 is applied over the entire surface 14 of the roof deck 10, thereby presenting a complete moisture barrier and presenting the first part 16 of the hook and loop fastener for use in securing the shingles 20 thereto. A first course or row of shingles is then laid along the lowermost edge of the roof deck 10. The shingles 20 of that first row are laid so that their bottom edges 24 extend slightly beyond the lowermost edge of the roof deck 10. The second part 22 of the hook and loop fastener (having hooking stems thereon) engages upon contact the first part 16 to secure each shingle 20 to the roof deck 10. Urging the first and second parts 16 and 22 together by pressure further engages the hooking stems and fiber loops for secured (but still detachable) engagement A second row or course of shingles 20 is then laid to partially overlie the first course As illustrated in FIG 4, the tab 38 of a shingle 20 in a second course is aligned to overlie the upper header portion 32 of the shingle 20 in the first course Further, the bottom edge 24 of the shingle 20 of the second course is aligned to overlie the seal-down asphalt strip 40 on the front surface 39 of the shingle 20 of the lower course Again, once aligned (as seen in FIG 4), the shingle 20 of the second course is laid onto the roof deck 10 so that the hooking stems of its second part 22 engage the fiber loops of the first part 16 This overlying arrangement is sequentially continued until the entire roof deck 10 is covered with shingles 20 (see FIGS IB and 4)

While each shingle 20 is releasably adhered to the roof deck 10 via the hook and loop fastener structures, the shingles 20 themselves become bonded together via the seal-down asphalt strips 40 As the roof is exposed to a heating history (seasonal elevated temperatures and exposure to the sun), the heat curable asphalt strip 40 softens and "flows" onto the back surface of the shingle tab of the overlying shingle 20, thereby adhering the two overlapping shingles together

FIG 5 illustrates in enlarged detail the hook and loop mechanical fastener engagement relationship The first part 16 has a plurality of exposed fiber loops 45, some of which are engaged by the second part 22 The second part 22 in turn is formed as a generally planar substrate 50 having a plurality of hooking stems 52 projecting outwardly therefrom It is desirable for the hooking stems 52 to be formed integrally with the substrate 50 Each hooking stem 52 includes means for hooking an opposed surface (such as a loop material), which is shown as a head 54 on the end of each hooking stem 52 The head 54 may be any suitable shape or configuration to serve as a means to snag one or more of the fiber loops 45 for engagement therewith upon contact It is desirable for the second part 22 to be formed from 3M product SJ3504, available from Mnnesota Mining and Manufacturing Company, Saint Paul, Mrmesota Suitable hooking structures and methods of their fomvation are disclosed in Melbye et al U S Patent No , Chesley U S Patent No 5,505,747, Nestegard U S Patent No 4,894,060, Thomas et al U S Patent No 5,058,247, and in pending U S patent application Serial No 08/181,195 (filed January 14, 1994), pending U S patent application Serial No 08/048,874 (filed April 18, 1992), and pending U S application Serial No 08/372,106 (filed January 13, 1995), which are all incorporated by reference herein

As illustrated in FIG 5, each shingle has an asphalt coating 56 on a back surface of a shingle substrate 58, and an asphalt coating 60 on a front surface of the shingle substrate 58 Sand particles or granules are embedded in the asphalt coatings 56 and 60 on both surfaces of the shingle substrate, backing sand 62 on the back surface and facing granules 64 on the front surface The facing granules 64 on the tabs 38 are prime granules and may include decorative features

A roof covering assembly formed according to the present invention provides a durable, water-resistant and inexpensive barrier to the elements Its assembly causes no damage to the roof deck or a moisture barrier layer laid thereon by use of penetrating nails, staples or other such fasteners Thus, the present roof covering assembly provides a roof covering of high integrity, convenience and versatility

The non-invasive hook and loop fastener has the advantage of radically simplifying the construction process It allows easy repositioning of shingles during assembly if they are misaligned or misplaced This further allows versatility and experimentation during assembly to achieve desired shingle color combinations, patterns or effects Further, the roof covering assembly of the present invention can be assembled relatively quickly and without highly skilled laborers As a result, the workplace is safer and cleaner

The degree of adhesion achieved by the hook and loop fastener is a function of many variables Some of these include the density of the hook and loop components, their relative sizes (e g , height of loops and length of hooking stems) and the weight of the shingle itself A low profile hook and loop fastener structure is desired The engaging force can be increased by increasing the relative surface area of the hook and loop fastener (e g , by increasing the size of the second parts 22 on the back surface 41 of each shingle 20) or by other means such as changing densities of the hooking stems or head sizes, etc Higher engaging forces may be desired in climates where high winds are more likely (such as hurricane-prone areas)

A further advantage in using a hook and loop fastener structure is that the loop material provides a cushioning layer for the shingles This may enhance the aesthetic appearance of the roof covering by giving it a three-dimensional aspect The hook and loop fastener provides yet a further advantage for the roofing structure by providing some inherent expansion between relative roofing components without undue strain or damage For example, the components of the roofing assembly are formed from different materials (e.g., wood, asphalt, etc.), which will expand and contract at different rates as the temperature changes. The use of a hook and loop fastener allows some give laterally (without sacrificing engagement strength) to facilitate such different thermal expansion rates of materials. Indeed, relative movement of the shingle and roof deck may actually enhance the holding force of the opposed hook and loop fastener parts by causing them to work together and further engage. While the orientation disclosed above has the loop part of the hook and loop fastener on the roof deck and the hook part of the hook and loop fastener on back surface of the shingles, that orientation may be reversed.

Numerous alternative constructions are also possible for the inventive roof covering assembly. For instance, in FIGS. 6 A and 6B, the first part of the hook and loop fastener is disposed on the roof deck 10 in longitudinally extending strips 70, rather than covering the entire roof deck 10 with mechanical fastener material. Such strips 70 could be applied in various ways. For example, the strips 70 having exposed fiber loops on their top side may have pressure sensitive adhesive on a back side and be directly applied to the top surface 14 of the roof deck 10, or onto a roofing felt layer (such as felt sheets 72 in FIG. 6A) applied over some or all of the roof deck 10. Alternatively, one or more strips 70 may be disposed on a larger sheet of water- impervious material which has pressure sensitive adhesive on a back side thereof for covering the entire roof deck with a water-resistant layer. The strips 70 are arranged across the roof deck 14 to align with the second part of the hook and loop fastener on the back surface of the shingles 20, as illustrated in FIG. 6B.

FIG. 7 illustrates an embodiment of the roof covering assembly of the present invention wherein each shingle 20 is again secured to the roof deck 10 via opposed hook and loop fastener components 16 and 18, but where overlapping shingles are also connected using opposed hook and loop fastener components. In other words, the seal-down asphalt strip 40 on the front surface of the shingle 20 is replaced with opposed complementary hook and loop fastener parts 116 and 122 borne on the shingles 20. The first part 116 (having exposed fiber loops) is on the front surface of the shingle 20, and the second part 122 (having the hooking stems) is on the back surface, adjacent the bottom edge 24. The first row of shingles 20 have a second part 123 adjacent their bottom edges 24 which engages the first part 16 on the roof deck 10. This type of mounting arrangement provides the advantage of immediate securement of the tabs 38 of each shingle 20 to the underlying structure. There is no need to wait for the sun to heat and soften an asphalt bonding strip in this embodiment— the assembly is immediately resistant to high winds and adverse weather conditions without waiting for any heat exposure, bonding and curing of a seal-down asphalt adhesive

In the context of this disclosure, the term "hook and loop fastener" refers not only the hooking stem/fiber loop hook and loop materials (which are often referred to as Velcro®-type hook and loop material), but also to other intermeshing two-part mechanical fasteners FIG 8 illustrates a two-part, hermaphroditic, mushroom-shaped head mechanical fastener wherein the opposed fastener parts are formed and mated to engage upon pressurized contact In this embodiment, the roof deck 10 may have a water-impervious layer 80 adhered to its top surface 14, with one part 82 of the mechanical fastener adhered thereto by an adhesive or other suitable means (or formed integrally with the water-impervious layer) The other part 84 of the mechanical fastener is bonded to the shingle substrate 58 by an asphalt layer 56 The proposed mechanical fastener parts 82 and 84 have identical profiles in this example On each part, a plurality of stems 86 are formed, each with a mushroom-shaped head 83. The heads 83 have bottom edges which, when pushed together as illustrated in FIG. 8, engage to mechanically couple the fastener parts 82 and 84 together

FIG 8 illustrates but one example of such opposed mechanical fasteners Other examples are known by commercial names such as "Scotchmate" and "Dual Lock," both available from Minnesota Mining and Manufacturing Company, Saint Paul, Minnesota One advantage of using some types of mechanical fasteners instead of the Velcro®-type mechanical fastener is that engagement is not effective until some pressure is applied between opposing fastener parts Thus, the shingles can be laid out on the roof deck, and then realigned and moved without having to disengage the fasteners. The shingles are then affirmatively secured to the roof deck by applying pressure to the fastener components to "snap" them together Again, attachment ease (engagement by force) and holding power (disengagement strength) may be altered through the choice of stem density A further advantage from this type of mechanical fastener for unskilled laborers is the tactile feel and audible "click" or "snap" which can be heard when the fasteners interengage upon the application of such pressure

Although the discussion has centered on asphalt three-tab shingles, shingles of other materials and flat roofing constructions can also be adhered by the present invention In the case of a plastic shingle or tile, an in-mold application of the hooking stems may be possible directly onto the back surface of the plastic shingle or tile, as the shingle or tile component is formed. Stems could be molded as projecting from the back surface of the shingle or tile, and then heated during a post-molding manufacturing phase to form heads on the ends of the stems for hooking purposes. Likewise, while various adhesive means are disclosed herein, other means for securing the components together are equally applicable. The second part of the hook and loop fastener may be secured to the shingle by an asphalt coating or by some other form of bonding (e.g., ultrasonic welding) or some other suitable adhesive, whether thermally- activated or pressure sensitive or other. Further, the water-impervious layer disposed on the roof deck may itself comprise a coating or may be a discrete sheet adhered by means of a layer of pressure sensitive adhesive, so long as it is adhered to the roof deck to sufficiently prevent its separation during high winds.

Although the present invention has been described in detail above with reference to shingle roof covering embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For instance, in addition to being applicable to other shingle roof coverings, the teachings of the present invention are also applicable to flat roof coverings. Below are described three exemplary roof covering assemblies which have flat roof coverings that are secured to a roof with a hook and loop fastener, according to the present invention.

In one flat roofing embodiment of the present invention, a conventional EPDM roofing sheet, with a nonwoven fleece like material partially embedded in the underside thereof, can be secured with a hook and loop fastener. One such EPDM roofing sheet is manufactured by Carlisle SynTec Incorporated, of Carlisle, Pennsylvania, 17013, under the product designation "FleeceBACK" 100. FleeceBACK 100 Membrane incorporates a .045 inch (1 mm) or .060 inch (1.5 mm) thick Sure-Seal® (black) or .060 inch (1.5 mm) thick Brite-Ply™ (white-on- black) non-reinforced EPDM membrane laminated to a .055 inch (1.4 mm) thick non-woven polyester fleece-backing. FleeceBACK 100 Membrane is available in widths of 10 feet (3 mm) and lengths of 50 feet (15.2 m). In the flat roofing industry, the nonwoven materials are typically used to enhance the bond between the adhesive and the roofing membrane by providing mechanical bonding. This layer of nonwoven material also increases the stretch resistance of the roofing membrane. In this embodiment, instead of being used for better adhesion, the nonwoven fleece functions as the loop portion of the hook and loop fastener. The hook portion was a fabric cube gripping hook tape, with a high temperature pressure sensitive adhesive (PSA), manufacture by Minnesota Mining and Manufacturing Company under the product No. #956. Other suitable hooking structures and methods of their formation may be found in the references incorporated by reference above (e.g., U.S. Patent No. 5,077,870). This hook tape was bonded to a foam insulation board by the PSA. The EPDM sheet was laid over the hook covered foam board so that the hooks engaged into the nonwoven backside. It was observed that this attachment exhibited a high Shear strength in the range of about 15psi to about 20psi with moderate peel strength of at least about 0.75 lbs/in width. It is desirable for the attachment shear strength to be at least about 10 psi and the attachment peel strength to be at least about 0.5 lbs/in. width. It was also observed that as movement between the sheet and the insulation board increased, the performance of the hook and loop engagement kept improving.

In an alternative flat roofing embodiment, a loop fabric material, for example the woven loop material manufactured by 3M Company, Style No. SJ 3401, is substituted for the nonwoven fleece and embedded or adhered to the EPDM roofing sheet of the previous embodiment. These loop materials can be designed in conjunction with the hooks, according to techniques in the art, to increase or decrease the shear and peel performance of the attachment as desired. In another flat roofing embodiment, a 3M "Dual Lock" self mating

(hook and loop) fastener SJ-3550 was adhesively bonded to a foam insulation board with a High Temperature VHB™ PSA adhesive system and to an EPDM sheet using 3M Heat bondable tape #4981. When the self mating side of the EPDM sheet was applied over the self mating covered side of the insulation board, a roller was used to engage the self mating sides together. It was observed that this fastening system provided high shear strength and a moderate peel strength. One advantage of the self mating system was that it did not engage immediately upon contact between the sheet and the insulation board thereby greatly improving the ability to slide the sheet over the insulation board to get the proper alignment. Other hook and loop fasteners are disclosed in U.S. Patents Nos. 4,290,174, 4,290,832, and 4,322,875 and 5,040,275, which are all incorporated by reference herein.

Advantages of using a hook and loop fastening system, such as that disclosed above, to attach shingle and/or flat roof coverings to a roof can include: the elimination of VOCs; no need for curing or messy adhesives; no need to form holes through the roof covering; can be mounted to cover whatever area of the flat roofing membrane is desired to reduce the chances of ballooning; allows for easy engagement of the roof covering to the roof; and allows the roof covering to be cleanly removed for replacement. A self mating fastening system provides the additional advantages of: allowing for easier alignment and adjustability of the roof covering before engagement to the roof; and produces a positive locking feel and sound which provide a notification that the mating surfaces are engaged.

Claims

WHAT IS CLAIMED IS

1 A roof covering assembly comprising a first part of a hook and loop fastener securable onto a portion of a roof deck, and a roof covering disposable over the roof deck, having a front surface and a back surface, and having a second complementary part of the hook and loop fastener secured on a portion of the back surface thereof, wherein the roof covering is detachably engagable with the roof deck via the hook and loop fastener after the first part of the hook and loop fastener is secured onto the roof deck

2 The roof covering assembly of claim 1 wherein the first part of the hook and loop fastener is sufficient to cover the entire roof deck

3 The roof covering assembly of claim 1 wherein the first part of the hook and loop fastener is defined by a hook engaging material and wherein the second part of the hook and loop fastener is defined by a plurality of outwardly projecting hooking stems formed to releasably engage the hook engaging material upon contact therewith

4 The roof covering assembly of claim 3 wherein the hook engaging material is a material having a plurality of exposed fiber loops

5 The roof covering assembly of claim 3 wherein the hook engaging material is defined by a plurality of outwardly projecting mating stems formed to releasably engage the hooking stems upon forced contact therebetween

6 The roof covering assembly of claim 1 wherein the first part of the hook and loop fastener is in the form of strips for being aligned spaced apart across the roof deck

7 The roof covering assembly of claim 1 further comprising an adhesive suitable for securing the first part of the hook and loop fastener to the roof deck

8 The roof covering assembly of claim 7 wherein the adhesive is a pressure sensitive adhesive

9. The roof covering assembly of claim 1 wherein the first part of the hook and loop fastener is borne by a flexible, water-impervious substrate sheet.

10. The roof covering assembly of claim 1 wherein the roof covering is a flat roof covering comprising a membrane having a front surface and a back surface, the membrane having the second complementary part of the hook and loop fastener secured on a portion of the back surface thereof, wherein the membrane is detachably engagable with the roof deck via the hook and loop fastener after the first part of the hook and loop fastener is secured onto the roof deck.

11. The roof covering assembly of claim 10 wherein the second complementary part is a nonwoven material.

12. The roof covering assembly of claim 1 wherein the roof covering comprises a plurality of shingles for being disposed over the roof deck in overlapping courses, each shingle having a front surface and a back surface and each shingle having the second complementary part of the hook and loop fastener secured on a portion of the back surface thereof, wherein each of the shingles is detachably engagable with the roof deck via the hook and loop fastener after the first part of the hook and loop fastener is secured onto the roof deck.

13. The roof covering assembly of claim 12 wherein the second part of the hook and loop fastener covers only a minor section of the back surface of each shingle.

14. The roof covering assembly of claim 12 further comprising opposed parts of a complementary hook and loop fastener disposed on the shingles.

15. The roof covering assembly of claim 14 wherein the front surface of each shingle has a section thereof covered by a first part of the complementary hook and loop fastener and the back surface of each shingle has a section thereof covered by a second part of the complementary hook and loop fastener.

16. The roof covering assembly of claim 15 wherein the first part of the complementary hook and loop fastener on the front surface of the shingle is defined by a hook engaging material and wherein the second part of the complementary hook and loop fastener is defined by a plurality of outwardly projecting hooking stems formed to releasably engage the hook engaging material on the front surface of an overlapped shingle upon contact therewith.

17. The roof covering assembly of claim 12 wherein the second complementary part of the hook and loop fastener is secured to its respective shingle by an adhesive.

18. The roof covering assembly of claim 17 wherein the adhesive material is a heat curable adhesive material.

19. The roof covering assembly of claim 12 wherein each shingle has a bottom exposed edge and a top overlapped edge, and wherein the second complementary part of the hook and loop fastener is secured on the back surface of each shingle adjacent its top overlapped edge.

20. The roof covering assembly of each of claims 1-19 further comprising the roof deck.

21. A method for covering a roof deck with a roof covering, the method comprising the steps of: affixing a first part of a hook and loop fastener onto the roof deck; aligning a roof covering over the roof deck, the roof covering material having a second complementary part of the hook and loop fastener on a portion of the back surface thereof; and urging the roof covering against the roof deck with force sufficient to detachably engage the first and second parts of the hook and loop fastener together for holding the roof covering onto the roof deck.

22. The inventive method of claim 21 wherein the roof covering is a flat roof covering comprising a membrane having the second complementary part of the hook and loop fastener on a portion of the back surface thereof, the step of aligning comprises aligning the membrane over the roof deck, and the step of urging comprises urging the membrane against the roof deck with force sufficient to detachably engage the first and second parts of the hook and loop fastener together for holding the membrane onto the roof deck.

23. The inventive method of claim 21 wherein the roof covering is a plurality of shingles, with each shingle having the second complementary part of the hook and loop fastener on a portion of the back surface thereof, the step of aligning comprises aligning a first row of the shingles over the roof deck, and the step of urging comprises urging the shingles against the roof deck with force sufficient to detachably engage the first and second parts of the hook and loop fastener together for holding the shingles onto the roof deck.

24 The inventive method of claim 23 wherein the affixing step includes covering at least a portion of the roof deck with a layer of water-impervious material

25 The inventive method of claim 23 further comprising the steps of: providing an adhesive material on an overlapped section on a front surface of each shingle; aligning a second row of shingles over the roof deck so that the second row partially overlaps the first row of shingles and covers the overlapped sections of the shingles in the first row; and urging the shingles of the second row against the roof deck with force sufficient to detachably engage the first and second parts of the hook and loop fastener together for holding the shingles of the second row onto the roof deck and allowing the adhesive material between the overlapped shingle sections of the first and second shingle rows to bond the shingles together.

26 The inventive method of claim 25 wherein the adhesive material is a heat curable adhesive, and further comprising exposing the heat curable adhesive to an elevated temperature to facilitate the bonding together of overlapping shingles of the first and second rows