1. Field of the Invention
This invention relates to roofing. More particularly, this invention relates to a self-adhesive waterproof membrane or roofing material, which is particularly suited for application to flat or slightly pitched roofs and which requires no torching operation for its installation. Such a roofing product is generally of the type employed on commercial, industrial, and large multi-unit residential structures. However, use of this roofing product and method on smaller structures and residences is not excluded from the present disclosure. Still more particularly, this invention relates to a roofing product and method having an installation that is substantially free of Volatile Organic Compounds (VOC's), and which is applied to a building substantially without the use of torching or molten tar. Rather, the roofing material is pressure-sensitive, and is pressed into place and is further secured with roofing fasteners. Thus, concerns of air pollution, worker safety, and possible structural fire, are substantially eliminated by use of this invention.
2. Related Technology
Generally, the roof structure of a building which employs a substantially flat or only slightly pitched roof includes a structural portion, which may include roof beams or trusses, possibly a grid of stringers carried on the beams or trusses, and a roof deck or sheeting which is carried on the stringers. The roof deck or sheeting may be carried directly upon the roof beams or trusses in some roof structures. Upon this structural portion is generally disposed an outwardly (i.e., upwardly) exposed water proof membrane (i.e., the roofing material). The water proof membrane structure prevents water (i.e., from precipitation) from penetrating the roof structure. Generally, the roof is provided with a system of drains, and possibly a system of gutters, along with drain pipes or down spouts, to carry precipitation water away.
Such a roof structure may be substantially flat, or may be slightly pitched. Further, such a roof structure frequently has plural vent pipes (i.e., for ventilating, heating, and air conditioning of the building, for example), ventilator fans, air conditioning units, heaters, electrical service conduits and cable ducts, electrical transformers and switch gear, and other utility devices and facilities mounted on the roof, and with portions of these facilities and devices passing through openings in the roof structure.
Historically, such flat or slightly pitched roofs have been of “built up” construction. That is, after the structural portion of the roof is completed, one or more layers of “tar paper” in the form of strips or sheets from a roll would be put down on the roof decking or sheeting, and one or more layers of roll sheet roofing material would be applied over the “tar paper.” The strips of roll roofing material are slightly overlapped at their edges, and the roof membrane may include several layers of such overlapped strips with the strips in each successive layer all running horizontally. The roll roofing material is generally applied with molten tar, in what is known as a “hot mop” process. As used herein, “tar” refers to any of various dark-colored viscid products obtained by the destructive distillation of certain organic substances, such as coal or wood, coal tar pitch, viscid asphaltic materials, etc., and is used without limitation on the invention.
Further, the conventional roll sheet roofing is usually about 3 feet wide (or about one meter if metric sized), is utilized at a roofing site in the form of a rolled elongate strip which may be 15 feet or more in length, and would generally be applied by a “hot mop” method as mentioned above. In such a “hot mop” method hot molten tar may be carried by hand in buckets up a scaffolding, or may be pumped from a tar kettle (i.e., a tar heater and pump unit) on the ground, in order to be delivered by a temporary pipe line arrangement to the roof. This hot tar is then mopped or otherwise spread on the seams and over the face of the sheet roll roofing to seal the seams and provide an additional water proof layer. Generally granular mineral material is spread over the surface of the roof to provide protection for the tar from ultraviolet radiation in sun light.
Some forms of conventional roll sheet roofing have granular material already applied over most of the outer face of the strip of roofing material, and the seams between adjacent strips of this roofing may be formed by a “torch down” method. In such a “torch down” method, after a strip of roofing is put down, a pre-applied strip of tar on the top elongate edge of this one strip of roofing is heated and softened with a large torch immediately before the side marginal edge portion of the next-successive strip of the roll sheet roofing material is put down on the roof structure.
Understandably, such conventional roofing practices which involve the use of hot molten tar, and of large torches, frequently result in a worker being burned by the tar or torch. Further, as is well understood by anyone who has been within even a few hundred feet of such a roofing project, the use of hot molten tar releases large amounts of noxious VOC's into the atmosphere.
Still further, molten roofing tar is flammable, and roofing torches provide a ready ignition source. Consequently, the conventional torch methods of roofing installation have resulted in many roof fires, and in structure fires when a roofing fire spreads before it is contained. Even in cases in which a roof fire results but is stopped before it spreads to the structure, the roofers are at risk of injury as they attempt to put out the fire. In some areas, local fire departments and Fire Marshals require torch roofing projects to be carried out under a “hazard watch” condition, in which local fire stations are informed of the project, and have an emergency response plan worked out ahead of time for use in the event that a roof fire starts.
As a result, recently a new form of roll sheet roofing has come into use. This newer roll sheet roofing is intended to be pressure sensitive and “self adhesive.” That is, in much the same way that an adhesive bandage is applied to the skin by first removing a release sheet to uncover a layer of sticky pressure-sensitive mastic adhesive, such “self adhesive” roll sheet roofing materials are provided with a layer of sticky adhesive on the underside of the roofing material. This sticky adhesive is covered by an elongate strip of release sheet material, which may be a plastic film of a type that does not bond permanently to the adhesive material, for example. In the use of such a “self adhesive” roll roofing material, as each successive strip of roofing material is unrolled the release sheet is pulled off and the adhesive material on the underside of the strip secures it to the underlying roof structure. The adhesive material is capable of bonding to the underlying roof structure so that the successive strips are placed side by side and appear to form a lap joint between them.
That is, although experience has shown that this “self adhesive” roll sheet roofing material solves many problems of the old “hot tar” roofing materials and methods, it has new problems and deficiencies of its own. In other words, the “self adhesive” roofing materials have limitations with respect to the conditions under which they can be successfully applied. If the conditions of application are too cold (i.e., below about 55° F.) or too wet, then the self adhesive roofing materials will not adhere well to the underlying roof structure. This limitation is understandable in view of the fact that the adhesives generally utilized on the self adhesive type of roll roofing materials is viscous and must soften (i.e., become viscid) to engage and bond with the underlying roofing materials. Further, rain, snow or other precipitation falling on the roof before the seams have bonded may seep through the seams. The presence of such moisture further will delay or interfere with the bonding of the adhesives generally employed on self adhesive roofing materials. In such cases the self adhering roofing materials have been known to not satisfactorily adhere to the underlying roof structure. In the event of such a less than satisfactory adherence of the self adhering roofing materials, if a strong wind storm takes place while the roof materials are not securely adhered then some or all of the new roofing materials may be blown off of the roof. With the conventional self adhesive roofing materials, when an application must be made during ambient conditions that are too cold the hope is that the conditions will improve (i.e., become warmer) and that the new roof material will then adhere by action of its own adhesive before the new roof is exposed to a strong wind storm.
Further, the conventional self adhesive roofing materials provide only a single layer of coverage for the underlying roof structure with each layer of the material put on a roof. So, several layers may be necessary in order to achieve satisfactory weatherproofing.
In view of the deficiencies of the conventional related technology, it is an object of this invention to overcome one or more of these deficiencies.
Particularly, it is an objective for this invention to provide a self-adhesive roll roofing material that has improved moisture resistance at the seams, even when applied in cold conditions.
Accordingly, the present invention, as seen in a particularly preferred exemplary embodiment, provides a roll roofing product including an elongate strip of inorganic fibrous sheet material permeated with an asphaltic matrix; the elongate strip defines a pair of upper elongate longitudinal facial portions each about one-half as wide as the strip of sheet material. One of the pair of upper elongate longitudinal facial portions carries a covering layer of protective coarse granular material, and the other of the pair of upper elongate longitudinal facial portions carries a coating of fine-dimension granular material sufficient to prevent self adhesion of successive wraps of the strip of roofing material when rolled on itself. The elongate strip further defines a pair of lower elongate longitudinal facial parts each about one-half as wide as the strip of sheet material. And, one of the pair of lower elongate facial parts carries a coating of an asphaltic adhesive, while the other of the pair of lower elongate longitudinal facial parts carries a coating of fine-dimension granular material effective to prevent self adhesion of successive wraps of the strip of roofing material when rolled on itself.
Other objects, features, and advantages of the present invention will be apparent to those skilled in the art from a consideration of the following detailed description of a preferred exemplary embodiment thereof taken in conjunction with the associated figures which will first be described briefly.
While the present invention may be embodied in many different forms, disclosed herein is a specific exemplary embodiment that illustrates and explains the principles of the invention. In conjunction with the description of this embodiment, a method of practicing the invention is described. It should be emphasized that the present invention is not limited to the specific embodiment illustrated.
Viewing
Downwardly, the roll roofing material 18 presents an elongate surface portion that is coated with an adhesive material effective to sealing bond the roofing material 16 to an adjacent strip of the roofing material, and also to sealingly bond the roofing material to the roof deck 14 as will be further explained. The remaining elongate surface portions of the roofing material 18, both on the upper and lower faces, are coated with a fine granular material. That is, about half of the upper face and about half of the congruent lower face of the roll roofing material 18 is coated with the fine granular material. This fine granular material is effective to prevent wraps of the material from sticking to itself when rolled for shipping. However, an upwardly disposed surface portion of the roofing material strip (which surface portion is coated with this fine granular material) is nevertheless bondable to a successive strip of the roofing material by action of the adhesive carried on the lower face of that next-successive strip of roofing material. Importantly, as is seen in
More particularly, viewing
Conversely, the portion 18b substantially laps over the part 18a of a preceding strip of the roofing material 18. As is seen in
Turning now to
Penetrated into and substantially through the sheet 20 is a matrix 22 of asphaltic material. This matrix of asphaltic material 22 adheres the fibers of the base sheet 20, and unifies the base sheet 20 and matrix 22 into a unitary durable structure. As is seen in
On the upper face of the strip 18 of roofing material as seen in
Thus, the coarse granular material 30 provides full coverage on facial portion 18b, and also a short distance onto the facial portion 18a. This marginal portion of facial portion 18a is effective to form the Z-shaped transition indicated in
Further, in order to insure proper overlap of the roofing material strips 18 when installed on a roof, the layer 30 will include an elongate line of longitudinally extending visual guide markers (i.e., perhaps in the form of a dashed chalk line) the location of which is generally indicated by arrow 30′ on
However, on the upper face of the roofing material strip 18, there is preferably a small exception to or exclusion of the coating 34 in a marginal edge portion (or selvage edge portion) 34′. In this selvage edge portion 34′ the fine-dimension granular material 34 preferably is partially removed and/or partially pressed into the base sheet 20 and matrix 22. Accordingly, in this marginal edge portion 34′, which may be about an inch wide, for example, the thickness of the roofing material 18 is reduced or tapered toward the adjacent side edge 20′. In this selvage edge portion 34′ however, there remains sufficient fine granular material so that the selvage edge portion is not sticky and does not cause adherence of successive wraps of the material 18 when rolled for shipping. It is to be appreciated, however, that because of the reduced thickness of the selvage edge portion 34′ when the successive strips 18 of roofing material 16 are overlapped during installation on a roof, the underlying strip of material 18 provides an edge thickness at selvage edge portion 34′ that is rather thin (that is, thinner than the full thickness created by the combination of base sheet 20 and matrix 22 along with the upper and lower coatings of fine-dimension granular material 34 and 34″—coating 34″ being introduced below). This rather thin dimension at the side edge 20′ of the underlying strip of roofing material (i.e., at the edge of selvage edge portion 34′) is easily accommodated and bridged by the layer 24 of raw asphaltic material on the overlying strip 18 of roofing material, so that void spaces (which could harbor moisture and lead to blistering of the roof membrane 16) are substantially eliminated. Again, it is to be noted that the dimensions 32 and 36 are each about one-half (½) of the width of the strip 18 of roofing material, while the dimension 28 is preferably at least one-half (½) inch more than the width of the portion 18a.
Finally, the remaining portion or part of the lower face of the strip 18 of roofing material is coated also with a layer 34″ of substantially the same fine-dimension granular material used on the upper facial part 18a (there indicated with numeral 34). Actually, the layer 34″ of fine-dimension granular material is applied to the combination of the base sheet 20 and matrix 22 before the layer of adhesive material 24 is applied, and the width of this layer 34″ of fine-dimension granular material as applied is almost one-half of the width dimension 18′. Accordingly, because the layer 24 of adhesive material is more than one-half the width of the strip 18 it slightly overlaps this layer 34″ of fine-dimension granular material. Further, the strip 26 of removable plastic film is also slightly wider than is the layer 24 of adhesive material, both to extend slightly beyond the edge 20″ and to extend slightly beyond the coating 24 onto the coating of fine granular material 34″. Thus, a marginal edge portion 26′ of the plastic film 26 lies atop of the fine-dimension granular material of layer 38 and is not adhered. So, this loose marginal edge portion 26′ of the film 26 is easily lifted up manually in order to start pealing of the film 26 off of the adhesive layer 24 (as will be further explained below).
Turning now to
Next, as is illustrated in
Further, considering
This method of installation of the roofing material 18 leaves substantially all of the area of layer 30 of coarse granular material (i.e., facial portion 18b) exposed on each of the preceding strips 18, and completely covers the fasteners 38. Thus, moisture from atop the installed strips 18 of roofing material making up membrane 16 would have to permeate between the strips 18 from the right hand side edge 20″ of a successive strip about one-half of the width of the strip in order to reach the left hand side edge 20′ of the preceding strip 18. So, the waterproof membrane 16 provides double layer coverage of the roof deck 14, and very good resistance against water penetration of the roof 10. Preferably, after each successive strip .18 of the roofing material is unrolled, partially overlapping the preceding strip of roofing material, and is fastened by fasteners 38, then a weighted roller is used over the membrane 16 in order to press the adhesive layer 24 firmly upon the facial portion 18a of the preceding strip, and to bond the adhesive 24 onto the roof deck 14 in stripe 24′ as well. This pressing action employs the self-adhesive or pressure-sensitive nature of the adhesive 24 of the roofing material 18 to interbond the successive strips 18 of roofing material.
It is to be noted that during the unrolling of the succeeding strip 18 of roofing material 16, the protective plastic film 26 is pulled away, as is indicated by arrow 26′ on
Moreover, it will be appreciated that the adhesive material 24 which is exposed when plastic film 26 is peeled off is effective to bond the successive layer of roofing material to the preceding layer over the entire length of the strip 18, as well as from side to side of the facial portion 18a having a width somewhat greater than the dimension 36. This bonding of adhesive layer 24 to facial portion 36 forms an interbonding of successive strips of the roofing material 16. The result is that moisture atop the applied roofing material 16 would have to penetrate between the successive layers or strips 18 about one-half of the width of the strips 18 in order to reach the roof structure 10. Because the raw asphaltic adhesive material 24 is such a tenacious adhesive, and because it remains viscid (i.e., it can soften or re-flow) and can re-bond each time it gets hot (i.e., from sunshine on a warm day), the roof 10 has somewhat of a self-healing nature, and remains water proof for many years after the roofing material 18 is installed to form the membrane 16. The fine granular material 34 on facial portion 36 does not prevent the adhesive 24 from interbonding. Further, the thickness of adhesive layer 24 is sufficient to bridge the thickness of the strips 18 at their side edge 20′ (i.e., at the selvage edge portion 34′) so that the creation of void spaces adjacent to this side edge is avoided. Such void spaces could possibly trap moisture which would expand when heated by the sun and cause the roofing membrane 16 to bubble or blister on a hot day. However, the present inventive roofing material prevents such bubbling.
Further, because of the combination of a considerable width of the interbonding area (adhesive 24 to granular material 34 and underlying base sheet 20 and matrix 22 over lateral dimension 28—which is preferably about 20½ inches wide). And this width combined with the viscid (or hot re-flow or re-softening) characteristic of the raw asphaltic adhesive 24, along with the secure attachment of the membrane 16 to the roof deck by fasteners 38. And combined with the additional sealing attachment effected as well by the adhesive 24 in bonding stripe area 24′, it is to be understood that differential thermal expansions and contractions between the roof structure 10 and the membrane 16 are well resisted or tolerated, and do not lead to separations of the strips 18 and leaking of the roofing membrane 16.
Those skilled in the art will further appreciate that the present invention may be embodied in other specific forms without departing from the spirit or central attributes thereof. Particularly, the extent of overlap of successive strips of a roll roofing material according to this invention need not be the one-half overlap described according to the most preferred embodiment. That is, an overlap of successive strips of one-third or less of the width dimension of each strip may be found to be acceptable and to make a successful roof structure in certain locations, and according to the desired service and life for a particular roof. However, in that case, the double-coverage feature of the most preferred exemplary embodiment would not be obtained. To recap that most preferred embodiment once again, the width dimension is 39½ inches, and the portions 18a and 18b respectively have widths of 20½ inches and 19 inches. The width of the layer 30 of coarse granular material is somewhat more than 19 inches, and the width of layer 34 (including selvage edge portion 34′) makes up the remainder of the upper face of the roofing material strip 18. On the underside of the roofing material strip 18, the width 28 of adhesive layer 24 is preferably 20½ inches, and the width of fine granular material layer 34″ is 19 inches. Thus, the stripe area 24′ of adhesive 24 presented to the roof decking 14 and sealingly interbonding with this roof decking is at least one-half (½) inch, nominally is about one inch, and may alternatively be about 1½ inches, in view of the tolerances obtainable in the manufacture of roofing materials. Because the foregoing description of the present invention discloses only a particularly preferred exemplary embodiment of the invention, it is to be understood that other variations are recognized as being within the scope of the present invention. Accordingly, the present invention is not limited to the particular embodiment which has been described in detail herein. Rather, reference should be made to the appended claims to define the scope and content of the present invention.