MX2013004541A - Corner patches and methods for tpo roofing. - Google Patents

Abstract

An outside corner patch for TPO roofing is formed from a circular piece of TPO membrane material being vacuum formed to define an array of flutes that extend from the center of the piece toward its edges. The flutes form ridges and valleys that generally are shaped as conical sections with the apex of the conical sections located at the center of the patch. The number and size of the flutes is optimized in such a way that, when the flutes are stretched flat, the patch conforms to and fits flat against the surfaces of an outside corner formed by the intersection of a roof deck with an upward protrusion from the roof. The TPO outside corner patch is applied over the corner and thermally welded to surrounding TPO membranes on the roof deck and the protrusion to form a watertight seal at the outside corner.

Description

CORNER PATCHES AND METHODS FOR POLIOLEPHINE ROOFING THERMOPLASTIC (TPO) Field of the Invention This description generally relates to materials and methods for thermoplastic polyolefin membrane (TPO) roofing and more particularly to TPO exterior corner patches for a seal around the ventilation grilles and other structures that are projected from a roof structure.

Background of the Invention It is common for commercial ceilings and others that are substantially flat to be sealed with the waterproof membrane such as the membranes coated with polymers, more commonly referred to as thermoplastic polyolefin membranes or simple TPO membranes. In general, all these roofs include several protrusions and project upwards from the roof platform such as, for example, ventilation grilles, duct network, air conditioning units, and the like. The provision of an airtight seal to. water around such protrusions, and particularly where the corners of the protrusion contact the flat roof platform, can be a challenge. More specifically, it is possible to wrap the protrusion at least partially with a skirt of the, Ref. 240766 TPO membrane with the bottom edge portion of the skirt widening to cover and be heat sealed in the roof membrane. However, this requires that a skirt be cut along the bottom of the corners of the protrusion, which leaves a region where the corners come into contact with the unsealed flat roof and is subject to leakage.

Corner pieces made of TPO have been developed to address this problem. For example, the Firestpne® ReflexEON® interior / exterior corner patch is a molded piece of TPO plastic with the general shape of a corner at a right angle permanently molded into it. The molded corner is placed around the lower corner of the protrusion and the patch is heat sealed on the surrounding TPO membranes to seal the corner. In contrast, GenFlex® TPO reinforced outer corners are corners made in factories made of high-performance TPO roofing membranes. These are usually made by cutting along a square piece of the TPO membrane from its center to a corner and then extending the membrane out of the slit to cause the opposite corner to form a loose fold. The gap between the extended edges of the slit is then filled with another piece of the TPO membrane, which is heat sealed and placed to form a unitary corner patch. In use, the loose bend is applied around the lower corner of a protrusion and the patch is heat sealed to the surrounding TPO membranes in the roof and the protrusion to form a watertight seal.

Other examples of the solutions attempted can be found in U.S. Patent Nos. 4,700,512; 4,799,986; 4,872,296; and 5,706,610. It has also been common in the past for ceiling membrane installers to tailor their own corner patches on the site by heating, elongate, cutting and otherwise manipulating small piece of TPO membrane. Corner patches and other solutions in the past have not been entirely satisfactory for a number of reasons including that they do not fill well around the corners, they must '' stack '' to fit an appropriate corner, thus risking the ability to form a reliable seal, and / or contain heat-sealed joints that can fail and result in a leak There is a need for a corner patch that satisfactorily addresses the drawbacks and problems of the prior art.

Brief Description of the Invention In summary, we describe a patch for flat TPO sealed ceilings that seal the lower outer corners of roof protrusions such as vents, conduit networks, air conditioning units, where the corners are put in contact with the flat roof. In one embodiment, the patch is made of a circular preform of TPO material that is vacuum formed to produce a plurality of radially extending grooves or peaks and valleys in the patch. This is referred to herein as a daisy wheel configuration. The number of grooves, the depth of each groove, and the radius of the preform are optimized according to the methods of the invention such that the patch fits into an outer bottom corner of a roof protrusion perfectly or almost perfectly when the grooves extend. The patch can then be heat sealed to the surrounding TPO membranes on the protrusion and roof to provide a watertight seal where the corners of the protuberances come into contact with the flat roof. The TPO daisy wheel corner patch of this description can also be optimized for corners that are not orthogonal; that is, where the sides of the protuberances and the roof do not form right angles with respect to each other. This has generally not been possible with the prefabricated corners of the prior art and has required the tedious manufacture of the custom corner patch in search of acceptable results. The patch of this invention is also easily and efficiently packaged because the shape of the daisy wheel of the patches allows them to nest together in a compact pile.

In this way, an improved prefabricated TPO corner patch is now provided which is adapted to the corner for which it is perfectly designed to provide a reliable water tight seal, ie compact and efficient to stack, store and transport, and can used for orthogonal outer corner shapes and others commonly found in commercial flat and semi-flat roofs. These and other aspects, features and advantages will be better understood after review of the detailed description set forth below when taken together with the accompanying figures, which are briefly described as follows.

Brief Description of the Figures Figure 1 is a perspective view of a section of a flat TPO sealed roof with a protrusion illustrating a preferred application of the outer corner patch TPO.

Figure 2 is a perspective view of an outer corner patch TPO that modalizes the principles of the description in a preferred form.

Figure 3 is a perspective view of a circular TPO preform with the corner patch of this molded description illustrating design variables to optimize the number and depth of the grooves for a particular corner.

Figure 4 shows a generic protrusion with a corner patch and illustrates how a design circumference for a patch of a given radius is determined.

Figure 5 is a graph illustrating the results of the optimization methodology of the present disclosure.

Figure 6 illustrates the variables involved when designing an exterior corner patch for a non-orthogonal protrusion, in this case a wedge-shaped protrusion on a flat roof.

Figure 7a is a side elevation view of a non-orthogonal roof protrusion that forms a right angle at two of its corners.

Figure 7b is a side elevation view of a non-orthogonal roof protrusion that forms an obtuse angle at two of its corners.

Figure 8 illustrates an outer corner patch applied to a roof protrusion having two faces that are not orthogonal to the roof plane.

Figure 9 is a geometric construction illustrating the variables involved when designing an outer corner patch for a protrusion that has two non-orthogonal faces.

Figures 10a and 10b illustrate outer corner patches that fit the corners of sharp angled pyramid corners and obtuse angle pyramid corners.

FIGS. 11 and 11b illustrate the application of the methodology of this invention to the design of corner patches for outer corners having four intersecting sides where each one forms non-orthogonal angles with respect to each other.

Figures 12a, 12b, and 12c illustrate the invention in an alternative embodiment wherein the sections with grooves are formed at the ends of an elongated strip of TPO material to seal a joint from a protrusion and the corners at the ends of the joint with an individual patch Figure 13 illustrates a section of a commercial roof having a roof covering, a rectangular wall, and a parapet wall, the corners of which are sealed with various corner patches according to the invention.

Figures 14a and 14b illustrate an inner corner patch according to the invention for sealing the inner corner in a roof with a TPO membrane or other membrane base.

Detailed description of the invention Referring now in more detail to the figures, where like reference numbers indicate equal parts in all the various views, Figure 1 illustrates a section 11 of a flat roof having a protrusion 13. The protrusion is illustrated as a projection generic square ascendant from the roof deck. In reality, such projections take many forms and the protrusion 13 may represent, for example, a chimney, a vent pipe, a duct, and a platform or air conditioning unit, or anything else. In any case, the protrusion 13 and the flat roof cover form the outer corners 20, where the corners of the protrusion come into contact with the roof cover. In the illustrated embodiment, the outer corners 20 are orthogonal; that is, the faces of the protrusion and the roof platform are brought into contact at approximately right angles. However, the outer corner patch of this description is not limited to use with orthogonal outer corners but can be optimized for non-orthogonal outer corners.

The flat portion of the roof 11 is covered and sealed with a TPO membrane 14 as is known in the roofing art to prevent water from leaking into the building downward. A cutout (not visible) is formed in the membrane at the location of the protrusion and the peripheral edges of the cut extend from the bottom of the protrusion. In order to seal along these lower edges, a skirt or apron 16 of the membrane material TPO is wrapped around and seals the protrusion 13 with the bottom of the skirt 16 widening to coat the membrane 14. More particularly, the skirt 16, when installed, includes an upper portion 17 that covers at least the lower section of the protrusion and the flaps 18 that widen outward to coat and cover the membrane 14, to which the flaps 18 are thermally welded to. form a watertight seal. In order to allow the flaps 18 to extend outwardly, the TPO membrane forming the skirt 16 is cut lengthwise during installation at the lower corners of the protrusion, as indicated by the reference number 19. This leaves an outer corner 20 wherein the corners of the protrusion and the end of the cut are brought into contact with the roof platform that is subjected to leakage unless properly sealed. The outer corner patches 21 according to the present disclosure are applied to seal these outer corners 20, as detailed below.

An outer corner patch 21 according to the present disclosure is applied at each of the outer corners within the protrusion to form a watertight seal at these corners. Referring to the outer corner of the first plane in Figure 1, the patch of the outer corner 21 comprises a specially formed circular piece of TPO membrane material which has been grooved as detailed below, to conform to the shape of the corner outside when the patch extends. In this illustration, the corner patch 21 is applied below the upper portion 17 of the skirt and below the two adjacent flaps 18. It will be understood, however, that the patch can also be applied over the upper portion of the portion. upper 17 of the skirt and on top of the two adjacent flaps 18 if desired. In any case, the corner patch 21 is thermally welded to the material TPO of the skirt 16 and the roof membrane 14, as indicated at 22, thereby forming a water-tight seal at the lower outer corner of the protrusion. Thermal welding or heat sealing of TPO corners and other membrane membranes is well known in the commercial roofing business and thus the details of this process need not be explained in detail here.

Figure 2 illustrates a preferred configuration of the outer corner patch of this description before being applied to the outer corner of a protrusion, as illustrated in Figure 1. The patch 21 is generally circular in shape with a central region 26 and a periphery 27 and radially grooved to define a radially extending array of peaks 28 and corresponding to the radially extending valleys 29. This forms the daisy wheel configuration of the patch. The peaks and valleys expand in amplitude from a substantially zero amplitude in the central region 26 of the patch to a maximum amplitude in the periphery 27 of the patch. The patch 21 can be manufactured in a variety of ways. Preferably, however, a circular cut-out of standard TPO membrane material is heated and vacuum formed to generate the daisy wheel configuration with a predetermined number of peaks and valleys. Other possible manufacturing methods could include injection molding, thermoforming, pressure molding or similar known techniques. The patch shown in Figure 2 is illustrated with 10 peaks and 10 valleys defining the daisy wheel configuration. However, fewer or more peaks and valleys could be selected based on the optimization techniques described in detail below.

For the installation of the outer corner patch of this description, the patch is placed with its central region 26 aligned with and covering the corner where the faces of the protrusion come into contact with the flat roof. The grooves of the patch then extend substantially flat as the patch conforms to the contour of the outer corner. More specifically, the grooves extend until the patch lies flat against both sides of the protrusion and also lies flat against the flat roof membrane in the region of the corner. With the number of grooves and the sizes of the grooves optimized for the three-dimensional shape of the outer corner, the patch conforms almost perfectly with the faces of the protrusion and the roof, when it then extends, completely. The patch can then be thermally welded or heat sealed to underlie or superimpose, as the case may be, the TPO material of the upper portion 17 of the skirt, the flaps 18 and the roof membrane 14 in this manner forming a water-tight seal in the outer corner of the protrusion.

As mentioned above, in order that the outer corner patch of this description conforming to the outer corner, its configuration, i.e. the number and sizes of grooves should be optimized to the shape of the outer corner and the diameter of the patch . Most of the outer corners are orthogonal, but the patch can also be optimized for non-orthogonal outer corners if desired. The optimization methodology described immediately below is for an orthogonal outer corner. Figure 3 illustrates the design variables that go into the optimization process. The circular starting preform of the TPO material 31 of which the patch is to be formed has a center 0, a periphery 33 and can be divided into pie-shaped sections 34, each of which will deform into a peak in a generally of cone or a valley of the end grooved patch, as illustrated by phantom line 36. An imaginary sunken circle 37 can be constructed as an aid in the derivation of optimization algorithms. The variables shown in Figure 3 that are relevant to the optimization process of this invention are defined as follows. n: number of grooves (total of peaks plus valleys) rb: radius of the circular TPO preform rp: radius of the sunken circle a: hollow preform angle h: depth of level drop ß: depth angle of the groove. a, b, c, d and e identify the various useful points in the construction With these optimization variables identified, and with reference to Figure 3, it can be seen that for triangle oac: sin (/ 2) = ab / 2 / oa = ab / 2 / rb In this way: ab = 2rb sin (a / 2) (1) Where: a = 2 p /? (2) Assuming that a sunken circle will generate an arc when the flat preform is deformed, so that the edge of the canaladura forms the sunken circle. Then, for the acd triangle, we can see from the Pythagorean Theorem for right triangles that: ad2 = ac2 + cd2 o: rp2 = (ab / 2) 2 + cd2 but cd + h = rp in such a way that: rp2 = (ab / 2) 2 + (rp - h) 2 Solving this equation for rp gives: rp = ((ab) / 4 + h2) / 2h (3) and: sin (ß / 2) = bc / db = ab / 2 / rp so that: ß = 2 without "1 (ab / 2rp) (4) Therefore, for a given depth of descent of level "h", the radius of the sunken circle rp can be calculated from equation 3. Then, the circumference of the sunken circle is: 2 nrp and the length of the edge of the groove that will follow the contour of the sunken circle when the preform is deformed is: ß / 2p x 2nrp or simply Srp Finally, the total length of the edge of the perimeter of a grooved patch with n grooves, which will be designated the "grooved circumference" or Cf, is given by the total of the lengths of each individual groove, or: cf = · nSrp (5) Now, referring to Figure 4, which shows a flat elongated circular grooved patch conformed to the outer orthogonal corner, and considering that the radius of the grooved patch is equal to the radius of the preform rb, You can determine, using the following equation, the total length of the perimeter of a ribbed patch required for a patch to conform to the orthogonal corner. This "circumference of the design" or simply "the objective" should be called this length of the perimeter. (2nrf) + ¼ (2nrb) = 5/4 (2nrb) 6) The circumference of the design can also be derived considering that A in Figure 4 is ¾ of a circle while B and C are each ½ of a circle. Adding the circumferences of each of these partial circles gives: ¾ (2nrf) + ½ (2nrb) + ½ (2nrb) = 5/4 (2nrb) Therefore, the optimization routines can be run from a preform of a given radius by selecting several values of the level decrease of the groove h, and for each value of h, vary the number of grooves n until the combination of hyn generates a circumference corrugated cf that is equal or very similar to the circumference of the design given by equation 6. Figure 5 illustrates, in the form of a graph, the results of such an iteration to determine the optimal combination of n grooves and the decrease in level of the H-grooves required for a corner patch having a radius with a diameter of 10.16 cm (4 inches) to perfectly conform to the outer orthogonal corner. The design circumference or calculated objective of equation 6 is represented by the dark horizontal line in the graph. Each curve of the graph represents the corrugated circumference cf for one of the values of the descent of level of the groove shown in the box in the upper right part of the graph for several values of the number of grooves n. It will be noted that only the data points in each graph represent a realistic combination of h and n since n must be an even integer number.

It can be seen from Figure 5 that the following combinations of groove numbers n and groove level drops h generate, for a preform with a radius of 10.16 cm (4 inches) a grooved circumference very close to the circumference of the design: n = 12 and h = 1.76 cm (.69 inches) n = 15 and h = 1.27 cm (.5 inches) n = 20 and h = 1.02 cm (.4 inches) Any of these combinations would result in a grooved patch that would conform to the outer orthogonal corner when lengthened by becoming flat. However, due to manufacturing considerations, and to produce a relatively stiff and robust end product, the first combination of n = 12 and h = 1.75 cm (.69 inches) is considered the most optimal.

A TPO preform with a radius of 10.16 cm (4 inches) was developed according to the previous optimization methodology with 12 grooves and a groove level decrease of 1.75 cm (.69 inches) and tested on an outer orthogonal corner of a bulge The test patch proved that it conforms almost perfectly to the corner when it is placed with its center directly to a corner and its elongated grooves in plane to cover the cover on the contiguous sides of the protrusion. Of course, patches with a radius other than 10.16 cm (4 inches), such as, for example, 5.8, 15.24 or 20.32 cm (2, 6 or 8 inches) can be optimized according to the previous methodology in such a way that the radius of the starting TPO preform is not a limitation of the methodology or the invention.

The considerations are similar when designing an outer corner patch that fits almost perfectly on an outside corner - which is not orthogonal. Figure 6 illustrates such a situation. Here, a roof protrusion 51 has an angled face 52 defining two non-orthogonal corners 53 where the angled face comes into contact with the roof cover. More specifically, the corners 53 are wedge-shaped from the side, and extend upwardly from the roof deck at a right angle? with respect to the roof covering. The shape of a protuberance with orthogonal corners shows the phantom line and is identified with the reference number 54 as a relative comparison.

The profiling P of a corner patch that conforms to the wedge-shaped corner at a right angle is shown in Figure 6 with several identifying marks that are involved in the calculations when optimizing a corner patch to fit a corner non-orthogonal defined by the angle? Specifically, the strategic points around the circumference of the profile are identified as a, b, c, d, and e, and the sections of the profile defined by these points are identified as sections 1, 2, 3, 4 and 5. You will see that the total circumference S of the profile P (and in this way the required circumference of a flattened corner patch designed to fit in the corner) is ab + bc + cd + de + ea.

It can be seen from Figure 6 that sections 1, 2, 3 and 5 of profile P each consist of a quarter of a circle or nr / 2. However, unlike the previous example for an orthogonal corner, section 4 extends in less than a quarter of a circle and specifically extends by the angle? until the wedge-shaped side of the protrusion. In this way the length L of the segment can be calculated by the following equation: L = xy (7) where the angle? it is expressed in radians. Therefore, the total circumference S needed to fit a corner patch of the non-orthogonal corner shown in Figure 6 is given by: S = ab + bc + cd + de + ea S = nr / 2 + nr / 2 + nr2 + yr + nr / 2 S = 4nr / 2 + yr S = 2nr + yr (8) Where yr is the length of the "extra arc" necessary to extend the wedge-shaped side of the protrusion. In the special case of an orthogonal outer corner, then? = n / 2 and the total circumference is 4/4 (2nr) | + nr / 2 = 4/4 (2nr) + 1/4 (2nr) = 5/4 (2nr), the results obtained in equation (6 ) anterior for an orthogonal outer corner. Equation 8, after, is the generalized equation for the design or objective circumference of a corner patch for a protrusion having a wedge-shaped non-orthogonal corner, such as that of Figure 6.

Having determined a design circumference according to equation (8), this design circumference can be replaced in the groove equations and optimized through repetition as described above for various values of the groove level decrease and a number of grooves n. The optimization methodology is the same as in the special case of an orthogonal outer corner. The result is an outer corner patch with an optimized number of grooves and a lowering of groove level which, when flattened, will adapt to the non-orthogonal corner almost perfectly. Below are the examples of this process for an outer corner at an acute angle as shown in Figure 6 as well as exteriors defined by other angles.

Examples The following examples are better understood with reference to Figs. 7a and 7b, showing a non-orthogonal outer corner with a right angle and a non-orthogonal corner with an obtuse angle respectively. 1. When y = 0 (corresponding to a flat surface), then the circumference of the generalized design is as given by equation (8) as 2nr + 0 = 2nr, the circumference of an ordinary circle. Obviously, no patch is required to fit a flat surface. 2. When ? = n / 2 (90 degrees), corresponding to an orthogonal outer corner, then the circumference of the given design being equation (8) is 5/4 (2nr) as seen above. 3. When ? is an acute angle, ie 3n / 4 (corresponding to an angle of 45 degrees), then the circumference of the design given by equation (8) is 2nr + nr / 4 = 9/8 (2nr). This can also be expressed as 2nr + 1/4 (2nr). 1/8 (2nr), where the last term represents the length of an optimized orthogonal arc that must be "removed" to adapt an exterior corner with a 45 degree angle. This is indicated by the term "arch to be removed" in Fig. 7a. 4. When ? is an obtuse angle, that is 3nr / 4 (corresponding to 135 degrees), then the circumference of the design given by equation (8) is 2rir + 3nr / 4 = 11/8 (2nr). Again, this can be expressed as 2nr + 1/4 (2nr) + 1/8 (2nr), where the last term represents the length of an optimized orthogonal arc that must be "added" to adapt the outer corner to an angle of 135 degrees. This is indicated by the term "arch to be added" in Fig. 7b.

It will therefore be seen that the generalized equation for the circumference design of an outer corner patch can be used to optimize that a patch fits almost perfectly to an outer corner having an angle that can vary between 0 degrees and 180 degrees.

What happens in the case where more than one face of the roof protrusion is non-orthogonal with respect to the roof plane? Such a protrusion is illustrated in Fig. 8 where both faces f1 and f2 are seen to extend upwardly from the roof deck at a minor acute angle of n / 2 (90 degrees). This will be referred to herein as a "pyramid bulge." An exterior corner patch can be designed for such a pyramid bulge with additional refinement of the equation for the circumference of the design, as described below.

Referring to Fig. 9, the geometry of the pyramid protuberance is illustrated in the three-dimensional space defined by the X, Y, and Z axes. The pyramid protuberance has the face fl defining an acute angle d with respect to the cover of the roof and face f2 that defines an angle? with respect to the roof covering. An outer corner patch P is shown in a flattened configuration that forms the faces of the pyramid protuberance with points a, b, c, d, and e defined by the circumference of the patch at strategic locations. The points A, B, C, and D are also defined in the illustration of Fig. 9. The circumference of the design S for the outer corner patch again equals ab + bc + cd + de + ea. For the geometry of the pyramid corner, the equation becomes: S = nr / 2 + nr / 2 + nr / 2 + 5r + yr (9) where d is the angle in radians formed by the triangle OBC with respect to the XY plane and is the angle in radians formed by the triangle OAB with with respect to the XY plane. With the angles yd defined for a non-orthogonal outer corner (or orthogonal corner for that question), then the design circle S can be calculated and subjected to the optimization methodology described above to design an outer corner patch with the appropriate number of grooves and the appropriate sunken circle in such a way that when the patch is flattened, it will adapt at the outer corner of the pyramid protrusion almost perfectly.

As an example, assume that both sides of a pyramid protrusion form an angle n / 4 (45 degrees) with respect to the roof covering. Then, using Equation 9, the circumference of the design can be calculated as follows: S = nr / 2 + nr / 2 + nr / 2 + nr / 4 + nr / 4 S = 3/2 (nr) + 1/2 (nr) S = 4/2 (nr) = 2nr Of course, the most generalized equation (9) should reduce equation (8) in the case of a single face that is angled with respect to the roof covering and equation (6) in the case of an orthogonal outer corner, which it looks like it results in: Where d = n / 2 (90 degrees) and? = n / 4 (45 degrees), then equation (9) becomes: S = nr / 2 + nr / 2 + nr / 2 + nr / 2 + nr / 4 . S = 4nr / 2 + nr / 4 S = 8/4 (nr) + 1/4 (nr) = 9/4 (nr) = 9/8 (2nr) which is the result in example 3 above. Similarly, if both? and d are n / 2 (90 degrees), then equation (9) should reduce equation (6) for the case of an orthogonal outer corner, which looks like it results in: S = nr / 2 + nr / 2 + nr / 2 + nr / 2 + nr / 2 S = 5 / 2nr = 5/4 (2nr) As with Equation 8, the most generalized equation 9 works with acute angles and obtuse angles as illustrated in Figs. 10a and 10b. Again, once the circumference of the design is determined for any exterior corner configuration, then the optimization methodology described above is carried out with the design circumference determined to reveal a daisy wheel corner patch, which when it flattens, it will adapt almost perfectly to the corner.

Figs. 11 and 11b illustrate the application of the methodology of the present invention to design exterior corner patches for corners formed by the intersection of non-planar faces. For such cases, the calculation of the circumference of the design is done in a manner similar to that described above, except that more than two angles are variable in the general equation for S.

Figs. 12a, 12b, and 12c illustrate another variation of the invention comprising a rectangular strip of TPO or another roof membrane of length L grooved at its ends. As shown in Fig. 12a, this embodiment of the invention is suitable for situations where the length L of one side of the roof protuberance is known in advance and the angle? that the protrusion formed with the roof covering is also known. The circumference is determined by the outer corner that defines the angle? as described above. The optimization methodology is then carried out to determine the optimum number of grooves and the radius of the optimum sunken circle as described. However, after optimization, the grooves are equally separated and formed at the semicircular ends of the elongated blank as illustrated in Fig. 12b. The result is an elongated patch designed to seal both the straight seam and the corners formed by a protrusion on the roof of a commercial (or residential) building.

Fig. 13 illustrates a section of a roof with various types of corners sealed with corner patches according to the invention. The roof has a cover 61 sealed with a membrane according to known techniques. A rectangular wall 62 extends along one side of the roof and a parapet wall 63 extends along the adjacent side of the roof to contact the rectangular wall at a corner of the roof. The parapet wall 63 is characterized by an angled interior face 64 extending downward towards the roof cover 61. The rectangular wall forms an orthogonal outer corner 69 at its end and the parapet wall 63 forms an exterior corner in the shape of wedge 68 at its end. The orthogonal outer corner 69 is sealed with an outer corner patch 66 optimized for an orthogonal outer corner according to the first embodiment described above (which could also have been designed using the equation given in Fig. 9 with both predetermined angles an / 2 ). The wedge-shaped outer corner 68 is sealed with a generalized outer corner patch according to the second embodiment described above (which could also have been designed by the third embodiment with an angle equal to n / 2).

The inner corner 67 formed by the junction of the rectangular wall 62 and the parapet wall 63 is sealed by means of an inner corner patch 71 according to the invention. The inner corner patch is modeled or on the contrary formed with three faces, two of which are orthogonal to cover the roof cover and part of the face of the rectangular wall and the third of these angled at an angle? in order to adapt comfortably against the angular wall 64 of the parapet wall. Such inner corner patches may be pre-molded from TPO or other membrane material with various fixed angles in the patch to form the inner corners of various angles and configurations. For example, Fig. 14a illustrates an inner corner patch 73 for an orthogonal inner corner having faces 74, 75, and 76 that are mutually orthogonal. FIG. 14b illustrates an inner corner patch 77 having orthogonal faces 78 and 81 and face 79 that forms an angle? with respect to the face '81. This is a type of patch seen in the inner corner in Fig. 13. Of course, inner corner patches can be molded or formed with all their non-orthogonal faces to accommodate unusual interior corners in commercial or residential ceilings. The inner corner patches do not require optimization as the outer corner patches since each one is configured for a correspondingly formed inner corner.

The invention has been described herein in terms of preferred embodiments and methodologies considered by the inventors to represent the best mode for carrying out the invention. However, numerous additions, deletions and modifications to the embodiments illustrated by those skilled in the art could be made without departing from the spirit and scope of the invention as set forth in the claims. For example, the patch has been described within the context of flat commercial roofing. However, the invention is not limited to flat roofs or commercial roofing, but can be adapted to seal corner protrusions in non-flat roofs. Certainly, the invention can be applied in non-roofing scenarios such as in metal plate structures, and bowls of tubs and showers, and the like where it is desired to seal the outer corners of the protuberances. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (12)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A corner patch for forming and coating a corner formed by a protrusion of a roof covering, characterized in that the protrusion has a first face projected upwardly at an angle d in radians with respect to the roof cover and a second face adjacent to the roof. first face and that is projected upward to an angle? in radians with respect to the roof covering, the corner patch made of a flexible material and comprising a body formed of a substantially circular blank having a radius rb and a central region, and a number n of grooves substantially in shaped conical section formed in an outer radial manner from the central region, the number h and the sizes of the grooves are optimized in such a way that when the corner patch is flattened, it forms the corner when the corner patch is applied to it , each groove has a shape defined by a sunken circle located on the periphery of the corner patch and establishes a lowering of groove level h, and where n and h for a given rb substantially satisfy the equation? ßt? nr / 2 + nr / 2 + nr / 2 + 5r + yr where: ß is the depth angle of the groove, and rp is the radius of the sunken circle.

2. The corner patch according to claim 1, characterized in that the body is made of a thermoplastic polyolefin membrane.

3. The corner patch according to claim 1, characterized in that d e? are selected from the group consisting of d e? they are sharp; d is acute e? he is obtuse; d is obtuse e? it is acute; and of ? They are obtuse. ·

4. The corner patch according to claim 1, characterized in that d e? they are orthogonal.

5. A roof characterized in that it comprises: a roof covering; a protrusion projecting upwards from the roof deck and forming a corner where two contiguous faces of the protuberance converge on the roof deck; a membrane that covers the roof covering; a membrane at least partially covering the protuberance; Y a corner patch according to claim 1, which covers and seals the corner.

6. The roof according to claim 5, characterized in that it is made of thermoplastic polyolefin.

7. The roof according to claim 6, characterized in that the corner patch is made of thermoplastic polyolefin.

8. The roof according to claim 5, characterized in that the membranes and the corner patch are coupled together to form a substantially water-tight seal.

9. The roof according to claim 8, characterized in that the membranes and the corner patch are thermally welded together.

10. The roof according to claim 9, characterized in that the membranes and the corner patch are made of a thermoplastic polyolefin material.

11. An elongated patch for forming and coating the straight seam and opposing corners formed by a protrusion of a roof covering, characterized in that it comprises a relatively flat central portion having a length corresponding to the length of the straight seam, a first end portion in one end of the relatively flat central portion, the first terminal portion being substantially one half of a patch according to claim 10, and a second terminal portion at the other end of the relatively flat central portion, the second terminal portion being substantially the Half of a patch according to claim 10, whereby the elongated patch forms the straight seam and the opposite corners of the protuberance to seal the protrusion.

12. A method for sealing a corner formed by two adjoining faces of a protrusion of a roof covering, characterized in that it comprises the steps of: (a) determine the angles d e? of the two charas contiguous with respect to the. roof cover; (b) obtaining a patch according to claim 10 which has been optimized for the angles d and y; (c) place the patch in the corner; (d) flattening the grooves of the patch to form the patch to the roof and corner cover; Y (e) seal the patch in the corner.