Roof element

Abstract: A roof covering element for covering a transition between a roof surface (7) and a part of a building (1) extending upward over the roof surface (7), where the roof covering element comprises a plate element (4), an internal covering (3), and an external covering 810), where the plate element (4) is fastened to the internal covering (3) by means of a first waterproof connection (5) and has a base part (6) having a second waterproof connection (8) with the surface (7) of the roof, where the outer covering (10) is fastened to the building part (1) by a third waterproof connection (12), and where the internal covering (3) at least partly is covered by the external covering (10), characterised in that the first (5) and the second (8) connection each comprises a glue joint, that the use of this glue does not require heating, and that the plate element (4) is a piece of elastic polymer film.

Description: The present invention concerns a roof covering element as described in claim 1. For roof covering ends at the edge of the roof, adjoining walls or around chimneys and ventilation pipes, it is common to use workable plates of lead. Use of this material is disadvantageous due to environmental considerations, but experience in Denmark, among others, have shown that other materials and methods of installation for similar use have not been convincing yet and are therefore not used to a large extent. Polymer films are known for roof covering and are e.g. rolled out on the roof in webs whereafter the webs are welded together in order to prevent moisture from creeping in under the covered roof. For sealing the roof around lead-in ducts in the roof, such as ventilation pipes, typically one or more pieces of film are laid around the lead-in and is welded together, whereafter the lead-in is covered by a plate or other suitable end. Also, it has be used to cover the through pipes or the cover pipes provided around the through pipes with a plastic material onto which the film may be welded. This is unsuitably complicated and requires that the fitter is working with great care in order to avoid leaks. Roof covering by this known method is furthermore not so stable over time as materials of different types expand differently by temperature changes, which may lead to breakage, especially when the elasticity decreases with time or the material moulders. French patent FR 2333913 discloses a polymer film, which is glued to the roof surface and a covering. Other kinds of covering intended for lead-in in the roof, for example as described in American patents US 5 605 020, US 5 381 632, US 5 226 263, US 4 211 423 and German laid-open publication DE 21 12 355. A further example is known from German patent DE 33 21 101 where a polymer film is provided with a hole which is less than the cross-section of the lead-in, whereafter the part of the film with the hole is forced over the pipe under tension whereby a rainproof connection is achieved. In case of rectangular lead-ins it is recommended that the film is bonded to the lead-in. The plate-like part of the film is then bonded to the roof surface, for example with an asphalt adhesive. This system is not suitable for use by lead-ins which are heated and thereby expand or are subjected to vibrations or mechanical action, for example exhaust pipes from oil-burners, as the plastic expands under heating, especially when the polymer film is subjected to tension because of wind. Furthermore, it is unsuitable to use this system by high pipes or chimneys where it may be difficult to reach the top of the pipe or chimney. Another example is known from American patent US 4 120 129 in which is described a flexible plastic covering for lead-ins which are step-wise narrowed in the upper part of the covering. Accommodation to the lead-in occurs by removing as many of the step-wise contractions so that the diameter of the upper opening is slightly less than the lead-in itself, whereafter the covering is forced over the lead-in and is sealed around the lead-in by means of clamps. This system is not reliable with respect to tightness and is not durable over long time by expansion and contraction of the pipe caused by temperature fluctuations, especially when used in connection with hot lead-ins and vibrating lead-ins. Furthermore, the lifetime of the clamps is limited when they are subjected to humid weather conditions, etc. The idea of two-level covering is generally known from American document US 4,937,991 which discloses a lead-in for use in weatherproofing a roof penetration including complementary mating half portion comprising a base plate, a generally semi-circle or stacked portion attached to and extending upwardly from the base plate, each base plate having an upwardly directed generally semi-cylindrical flanged edge disposed within the lower end of each semi-cylindrical stack portion, a longitudinal edge portion on each stack portion forming an elongated continuous channel for receipt of a corresponding smooth longitudinal edge of the opposite stack portion for snap-fit frictional retention of the two stack portions when mated with the edge portions of the base plates in abutment and a generally cylindrical counterflashing or cap, for surrounding a roof penetration and receiving the upper end portion of the mated stack portions in radially inwardly spaced relation therefrom. The cap portion is fitted with a gasket and optionally with an elastic seal. Similar forms of polymer covering exist where the polymer is fastened to the lead-in in different ways. Most of the systems are relatively expensive in making and are difficult to use, especially under adverse weather conditions and when the temperature is low as the polymer is less flexible at low temperatures. One of the problems with known systems is that it is difficult to achieve a satisfactory bonding and thereby sealing between the covering and the different materials that may constitute a roof surface, for example metal, slate, asbestos cement, concrete, plastic, or tile. A commonly used roof covering for lead-ins consists of two conical pipe stubs of metal, where one pipe stub is clamped about the lead-in as external covering by its upper narrow opening and is sealed, for example by means of temperature resistant silicone glue, and functions as upper covering for the other pipe stub, i.e. the internal covering disposed down under. To and around the other pipe stub, which is also disposed around the lead-in but not in direct connection with it, there is fastened a thin lead plate by soldering, selected so large that it abuts on the roof surface and thereby creates a covering between the other pipe stub and the roof. This system is commonly used because it has a number of advantages. Rain water is prevented from running down along the lead-in and into the roof as a sealing is provided between the upper conical pipe stub, i.e. the external covering, and the lead-in. The rain water will thus run down the side of the first conical pipe stub. Then the rain water drips down onto the second pipe stub and further onto the lead plate and then the roof. The system, which consists of two pipe stubs not connected with each other and having a certain mutual distance, has the advantage that the system is not deformed or damaged when the pipe changes length and position because of temperature fluctuations. Furthermore, there is only a very limited load on the glue joint between the upper conical pipe stub and the lead-in. The use of lead has the advantage that the material is durable, workable, and still stable and has a weight ensuring that it is not lifted off the roof because of wind. The lead plate is sometimes fastened to the roof with a glue, for example silicone. The drawbacks of this system are that lead is used which is not environmentally right. Furthermore, the soldering of the lead plate to one conical pipe is performed on site which is very cumbersome for the fitter in case of raining or snowing. Besides, the soldering may break during mounting of the lead plate when the lead is adjusted, typically by means of a hammer, to the roof structure. Lead plates are also used for roof covering around brick chimneys and by adjoining walls or attics. However, systems without the use of lead are also known. One example is disclosed in American patent publication US 5 381 632 where a covering system for a chimney is described. The covering system consists of an external covering and an internal covering. The external covering is fastened with nails or screws to the chimney and is sealed with a glue joint, such as silicone, to chimney. The internal covering consists of a strip of foam polymer disposed with its upper part under the external covering and with its lower part nailed to the roof, possibly under the roof plates. This system has the disadvantage that it is only suitable for flat roof constructions; and additionally, it is unsuitable to perforate the internal covering and the roof with nails or the like since this may create leakages, especially by wind force action on the covering. It is the purpose of the invention to indicate a roof covering for lead-ins or ends of roof coverings in general which substitutes lead so that it is without smudging and contamination of the surroundings, which is applicable by largely all kinds of roof covering, which has long life, which is simple and quick to fit, and which is cheap. This purpose is achieved by the present invention of the kind mentioned in the introduction which is peculiar by the features indicated in the characterising part of claim 1. The invention is a roof covering element between a building part and the roof surface itself where a piece of elastic polymer film is used which is fastened to an internal covering and sealed to the roof surface by another glue joint, and where additionally there is used an external covering connected waterproof with the building part. In this way is achieved a roof covering element having the same advantageous sealing properties as the known covering with lead but without using lead. The external covering may be waterproof connected with the building part in different ways, for example by a glue joint or a sealing rubber strip. The building part may e.g. be a lead-in or duct through the roof, like a ventilation pipe. In practice, the roof covering is achieved in this case by providing a piece of polymer film of suitable size with a hole which is less than the cross-section of a tubular internal covering. The internal covering will typically, like the external covering, be shaped as a conical tube, more like a truncated cone. The film is then stretched so that a larger hole is obtained, and the film is pressed down over the internal covering and is glued between the internal covering and the film. The internal covering with the polymer film is placed around the duct and the polymer film is fastened as base part to the roof surface by a second glue joint Finally, the external covering is placed around the duct and fastened to the duct with a waterproof connection, for example by means of a third glue joint. The position of the external covering in relation to the internal covering is selected so that the internal covering is shielded against rain water. By using two coverings in continuation of each other and partly overlapping, there is created the possibility for the lead-in having a certain freedom for expansion, contraction and lateral movement without the roof covering element becoming leaking due to rain water. By choosing two coverings there is also achieved the advantage that there is a very little load on the third glue joint between the duct and the external covering in contrast to the load on this glue joint in case the polymer film having been fastened directly on the external covering as it may be remembered that tensile action on the film during storm may be considerable. Furthermore, other advantages are achieved as described in the following. Internal and external covering may be made of different materials, such as synthetic material, though metal, especially aluminium, will be preferred. Truncated cones made of a bent, thin aluminium plate are well-known for use for roof coverings in connection with lead-ins and are proven to be applicable. The ducts usually have standard diameters why the internal and external covering may be prefabricated fitting to these prescribed sizes. In order to adjust the duct precisely to the duct, the external covering is designed according to claim 7 with a suitable coupling means consisting of two flanges, the mutual distance of which may be varied with e.g. screws. In this way, the diameter of the upper opening of the external covering may be varied and adjusted precisely to the duct. The invention has some similarities with the above described prior art where lead plates are used. But by using an elastic polymer film instead of lead, an environmentally correct solution is achieved. The polymer film is elastic and may therefore be adjusted to may different forms of roof surfaces, including a plurality of materials, such as tile, slate, polymer, and a plurality of shapes, such as plane, grooved, uneven or curved surfaces. The bonding of the polymer film to the internal covering may advantageously be performed on the factory, whereby this bonding process does not have to be performed by the fitter on the site of mounting, something which further facilitates the work on the site and makes this process independent of weather conditions. Such a prefabrication process is not possible with lead covering as the soldering on the internal covering is not stable enough for the transport from factory to the site of mounting on the building roof. The bonding at the factory between the polymer film and the internal covering not only thereby facilitates the work with the roof covering but also makes the whole process far cheaper than previously possible. In that case, bonding between the film and the roof is only to be performed for stabilising the covering and for forming a sealing so that rain water cannot penetrate into the roof. To substitute lead with polymer film has not been possible until now as no known types of glue have existed for bonding the film to the roof surfaces and to the known and used pipe stubs of aluminium. A type of glue, heat durable silicone glue, which according to prior art is used for fastening the external covering to the duct, has not proven to be useful for bonding polymer onto the duct or onto the internal covering. Tarry substances have not been satisfactory either as these substances were either of the kind that remains highly viscous and therefore does not give the required stability, or they were of another kind that have to be melted at high temperatures and which after cooling and setting loses the advantageous elasticity. Therefore, prior art has consisted of far more complicated, expensive and less durable solutions. Surprisingly, it has appeared that a type of glue known from the car industry for bonding car window panes to the frames arranged for that purpose in the car may be used with advantage. This kind of glue is distinguished by effectively adhering to almost all used materials for roof covering and the polymer film. Furthermore, it has long-term durability, also by temperature fluctuations and UV-light action, remains elastic, has a high breaking strength, may endure relatively high temperatures and is easy to handle. The film has the same properties so that the combination of this glue and the polymer film is suitable as a cheap and simple substitution for the lead covering. The glue is of the type vinyl trimethoxysilane or methyl dimethoxysilane. The invention is thus using materials known per se from different trades but in a new, surprising constellation. The glue may be used for all necessary glue joints in connection with the invention which has the advantage that it is not necessary that the fitter mounting the roof covering has several different types of glue with him, thus facilitating his work. The coupling means in the external covering additionally allows this kind of covering at ducts being so high that it is not suitable to lift the roof covering element above the top of the duct and then lower it down over the duct. In such cases, the coupling is opened, and the external covering is laid around the duct. In order to dispose the internal covering around the duct, it has to be cut up, e.g. perpendicularly to the longitudinal direction of the duct after which the internal covering finally has to be bonded together again. This is enabled with the very stable and long-term durable glue described in the invention. The principle of the invention in connection with covering of roof lead-ins has appeared being capable of transferring to roof covering at brick chimneys and at adjoining walls or attics. In this case, the external covering comprises an elongate rail which is fastened on the wall, usually by screws or nails. The polymer film is fastened on this rail with a waterproof first glue joint. The other side of the polymer film is fastened on the roof with a second glue joint The external covering is constituted by an elongate angle bar piece with a cross-section which is largely L-shaped with two legs. The first leg is disposed in a groove provided for that purpose in the wall and is fastened with a glue joint filling out the groove at the upper side of the part of the angle bar disposed inside the groove. Thus, not only the external covering is fixed but there is also established a waterproof sealing between the angle bar and the wall so that rain water cannot make its way under the angle bar. The bar is disposed right over the internal covering so that the covering is covered by the second leg of the angle bar extending partly down over the internal covering. If necessary in special cases, the glue joint may be supplemented with a further fastening of the external covering by screws, for example. In another embodiment, the roof covering may furthermore be used for covering roof windows, skylights or superstructure windows. The film, the base of which is connected with the roof surface, has been described above as being glued or bonded to the roof surface. However, it will also be possible to provide the base part on the roof without using glue, for example by sliding a part of the film under roof plates, e.g. at chimney edges. The invention is described more closely in the following with reference to the drawing, where: Fig. 1 is a draft of an embodiment of the invention for covering a lead-in in the roof, Fig. 2 is a draft of the external covering with the coupling means, Fig. 3 is a draft of an embodiment according to the invention for covering the transition between a wall and the roof surface, Fig. 4 is a draft of an embodiment of the invention for covering the transition between a roof window and the roof surface. Fig. 1 shows the invention in an embodiment for covering lead-ins or ducts in the roof. The duct 1 through the roof 2 is, for example, a ventilation pipe. The internal covering 3, which may have different shapes, is shown here in the form of a hollow truncated cone designed to fit the cross-section of the duct 1 and disposed around the duct 1. A piece of polymer film 4 is fastened to the internal covering 3 with a glue joint 5. Furthermore, the base part 6 of the film 4 is fastened to the roof surface 7 with another glue joint 8. In case the roof is covered by roof plates, there is also the possibility of pushing the film in under some of the roof plates, something which may be suitable for part 9 of the film 4 facing upward. An external covering 10 is provided tightly and firmly around the duct. A possible interspace between the upper opening 11 of the external covering 10 and the duct 1 is sealed with a third glue joint 12. The size of the opening in the external covering may be varied by a coupling means 13 which is a part of the external covering 10. The coupling means 13 of the external covering 10 is shown on Fig. 2, where Fig. 2a shows the external covering from the side, Fig. 2b shows the external covering from the side in enlarged version, Fig. 2c shows the external covering in cross-section with a section through a screw in the coupling means, and Fig. 2d shows the same section in enlarged version. The coupling means comprises two flanges 14 and 15 engaging each other and coupled together, e.g. by means of screws 16. The flanges 14, 15 are formed under the process of making the external covering 10. By tightening the screws 16, a reduction in the cross-section of the opening 11 is achieved. In the different embodiments of the invention, the internal covering as well as the external covering may in general be made of different materials, for example synthetic material or metal; for coverings for ducts or lead-ins, the making in aluminium with a thickness of 0.5 to 1 mm is preferred. The process, where the film 4 is fastened to the internal covering 3, may advantageously occur on the factory. Thereby the fitter is spared for this process on the site, making the system cheaper and more secure. The used ducts 1 have typically a size which belong to the relatively few standardised sizes. Therefore, it is also only necessary to make internal coverings with fastened polymer films in a limited number of sizes. For ducts with different roof inclinations it is, however, necessary to make different pipe stubs but since the single models of pipe stubs cover a broad range of roof inclinations, e.g. 0-5°, 5°-30° or 30°-45°, the necessary number of different embodiments by making and storing is very limited. A combination of internal covering 3 and polymer film 4 is a stable construction which is suitable for transport without risk of breakage during transport and mounting, even at low temperatures. Fig. 3 is a draft of a second embodiment of the invention where a covering of the transition between a wall 20, for example for a chimney or an attic, and the roof surface 7 is achieved. An internal covering in the shape of an elongate rail 23 is mounted on the wall with fastening means 21, e.g. screws. This rail 23 may be discontinued at suitable intervals so that the material may be folded in order thereby to create a suitable surplus of material which is sufficient to let the base part be accommodated to roof surfaces with very deep waves or other kinds of structures. At the lower part 22 of this rail 23 there is fastened a piece of polymer film 4 with a first glue joint 24. The base part 6 of the polymer film 4 is fastened to the roof surface 7 with a second glue joint 8. For mounting the external covering, the wall 20 is provided with a groove 26. The external covering comprises an elongate piece of angle bar 25 with a cross-section being largely L-shaped. However, other cross-sections of the angle bar are also possible. The L-shaped angle bar 25 has a first leg 31 disposed in the groove 26 and fastened to the wall by a glue joint 27 in the groove 26. The glue joint 27 forms a tight connection so that rain water cannot penetrate into the interspace 28 between the wall 20 and the external covering 25. The second leg 29 of the L-shaped section 25 faces downward and ends at a level which is lower than the upper edge 30 of the internal covering 23. Thereby is achieved a rainproof covering of the transition between the wall 20 and the roof surface 7. Rain water will thus run down the external covering 25, drip down onto the internal covering 23 and run further down the polymer film 4 and out on the covered roof surface 7. Fig. 4 shows the roof covering element according to the invention in an embodiment for use in roof windows. A special design is shown; however, the invention may be changed and adjusted for various roof window constructions. The roof window 40 has frame 41 which is partly lowered in the case 42 when the window 40 is shut. At the outer side 43 of the case 42 there is fitted an internal covering in the shape of an elongate rail 23 with fastening means 21, for example screws. The rail 23 may, for example, extend the whole way around the case 42. In this case it may be an advantage to make the rail 23 of a pliable plastic material as the rail can be made in webs and be stored in coils, either as an independent element or together with polymer film glued on it. At the lower part 22 of this rail 23 there is fastened a piece of polymer film 4 with a first glue joint 24. The base part 6 of the polymer film 4 is fastened to the roof surface 7 with a second glue joint 8. Over the internal covering 23 there is provided an external covering at the outer side 43 of the case. The external covering comprises an elongate angle bar 44 which is fastened on the outer side 43 of the case, e.g. with a glue joint 45 or a combination of glue joints and screws or glue joint and nails. The angle bar 44 extends downward to a level lower than the upper edge of the internal covering 23 whereby a rainproof covering of the transition between the case 42 and the roof surface 7 is achieved, corresponding to the example in Fig. 3.

Claims: A roof covering element for covering a transition between a roof surface (7) and a building part (1) extending upward over the roof surface (7), where the roof covering element comprises a plate element (4), an internal covering (3), and an external covering (10), where the plate element (14) is fastened to the internal covering (3) by means of a first waterproof connection (5) and has a base part (6) having a second waterproof connection (8) with the surface of the roof (7), where the external covering (10) is fastened to the building part (1) by a third waterproof connection (12), and where the internal covering (3) at least partly is covered by the external covering (10), characterised in that the first and the second connection (5,8) each comprises a glue joint, that the use of this glue does not require heating, and that the plate element (4) is a piece of elastic polymer film. Roof covering element according to claim 1, characterised in that the glue joints in the first and the second connections are provided with the same type of glue. Roof covering element according to claim 2, characterised in that the third waterproof connection (12) comprises a third glue joint which is provided with the same type of glue as used in the first and second connection. Roof covering element according to claim 1, 2 or 3, characterised in that glue of the type vinyl trimethoxysilane or methyl dimethoxysilane is used. Roof covering element according to claims 1 - 4, characterised in that the building part (1) is a wall, that the internal covering (3) is an elongate rail fastened to the wall by fastening means, that the external covering (10) comprises an elongate piece of angle bar, the cross-section of which is largely L-shaped with a first and a second leg, the first leg being disposed in a groove provided in the building part (1), the third connection being provided as a glue joint constituting the interspace between the upper side of the first leg in the groove and the inner upper side of the groove, and the second leg extending downward from the groove to a level lower that the uppermost edge of the internal covering. Roof covering element according to claim 1 - 4, characterised in that the building part (1) is a tubular duct through the roof, that the internal covering (3) comprises a first pipe stub with a first upper opening which is greater than the outer cross-section of the duct, that the first pipe stub is disposed around the duct, that the polymer film is provided with an opening disposed around and in close contact with the first pipe stub, that the external covering (10) comprises a second pipe stub disposed around the duct above the internal covering (3) where a glue joint constitutes a waterproof connection between the outer wall of the duct and the upper opening of the second pipe stub, where the lower opening of the second pipe stub is greater than the upper opening of the first pipe stub, and where the second pipe stub is disposed at a level compared with the first pipe stub so that the lower edge of the second pipe stub is lower than the upper edge of the first pipe stub. Roof covering element according to claim 6, characterised in that the first and the second pipe stub are truncated cones with the narrow end of the truncated cone at the top. Roof covering element according to claim 6 or 7, characterised in that the second pipe stub is provided with a coupling means from the upper edge to the lower edge, the coupling means comprising two flanges with mutually variable distance so that variation of the distance results in variation of the cross-section of the truncated cone. Roof covering element according to claims 1 - 4, characterised in that the building part (1) is a roof window, and that the case of the roof window protrudes above the plane of the roof, that the internal covering (3) is a rail extending around the outer side of the case and is fastened to the case with fastening means, that the external covering (10) comprises a frame the cross-section of which is largely L-shaped with a first and a second leg, the first leg being fastened to the frame above the internal covering with a glue joint, and with the second leg extending downward to a level lower than the uppermost edge of the internal covering (3). Roof covering element according to any preceding claim, characterised in that the internal covering (3) and the external covering (10) are of metal or plastic.

Inventors: POULSEN PER, POULSEN, PER
Applicants: POULSEN PER, POULSEN, PER
Application year: 2000
Main classification: E04D13
IPC codes: E04D13