A DEFORMABLE SHEET MATERIAL FOR ROOF FLASHING PURPOSES AND A METHOD OF MANUFACTURING SUCH A MATERIAL

Abstract: A deformable sheet material consists at least partly of a sheet metal or metal foil which is corrugated, eg. by rolling, in continuous waveform in two directions (A, B) substantially orthogonal to each other. The sheet material may consist of aluminium foil with a thickness between 0.05 - 0.4 mm designed as a ribbon or a strip which prior to the rolling is folded in the longitudinal direction where an intermediate layer, e.g. of aluminium, can be placed between the two material layers.

Description: A deformable sheet material for roof flashing purposes and a method of manufacturing such a material. The invention relates to a deformable sheet material for roof flashing purposes in connection with roof windows and similar roof penetrating building structures consisting at least partly of a metal sheet or a metal foil which has been corrugated in a conti¬ nuous waveform. Such deformable sheet materials are frequently used to provide water- and snowproof adaptations between roof penetrating building structures, especially roof windows, and the surrounding roofing which may consist of tiles or other forms of corrugated covering materi¬ als. In order to permit an adaptation of such flashing materials to the form of the surrounding roof covering by a purely manual deformation, the use of corrugated roofing materials of above-mentioned type made from lead or other forms of deformable metal foil as disclosed in, inter alia, DE utility model G 82 00 019.0, has in course of time also been proposed to replace the flat lead skirts with a thickness of 1-2 mm and originally used for this purpose. Concurrently with increasing concern of the environment, it has further been suggested to use a number of different sandwich or composite materials including those disclosed in the applicant's DK patent no. 148.064, EP patent no. 0 123 141 and DK patent no. 165.014, in order to avoid the pollution problems related to the use of lead. However, such sandwich materials have as a rule been considerably more expensive than pure lead flash¬ ings. Furthermore, both per se and as a consequence of their incorporation in a sandwich material together with partly elastomeric materials, the used metal foils have not always had the required lasting deformation pro¬ perties because of a certain remaining elastic resilien¬ ce. Based on corrugated lashing materials of the type disclosed in above DE utility model, it is the object of the invention to procure a new design of a flashing material which can be produced at a low price and has deformation properties fully up to the standard of those of the best sandwich materials. To this end, a flashing material of the above type according to the invention is characterized in that the material is corrugated in a continuous waveform in two directions substantially orthogonal to each other. The double waveform of the flashing material according to the invention entails that the area of the metal sheet or foil per unit area of the finished flashing material is substantially increased, which is decisive for a light manual deformability by the stretching of the crests and valleys of the waveform without necessarily stretching or butting the very foil material. As an appropriate foil material according to the invention, an aluminium foil having a thickness pre- ferably between 0.05 and 0.4 mm may be used. However, other forms of metal foils with good plastic deformation properties, eg. copper or zinc, may also be used. Moreover, according to the invention, it appeared that particularly good lasting deformation properties practically without resilience and at the same time an improved strength and rigidity can be obtained by using two folded up metal foil layers with a relatively small thickness. A preferred embodiment where the sheet material is designed as a ribbon or a strip, one long side of which is intended for connection with the roof penetrating building structure, is therefore according to the invention characterized in that prior to the corrugation in said waveform, the ribbon or strip is folded in the longitudinal direction along a folding line placed sub¬ stantially halfway between the two opposite long sides. Furthermore, the invention relates to a method of manufacturing a deformable sheet material as indicated above, which method according to the invention is characterized in that after rolling in a first direction for production of a first continuous waveform, a ribbon or a strip consisting at least partly of metal sheet or metal foil is corrugated in a second waveform sub¬ stantially orthogonal to the first by rolling in a second direction substantially orthogonal to said first direction. In the following the invention will be explained in more detail with reference to the schematic drawing where Fig. 1 shows in perspective a section of a strip- shaped flashing material for a roof window, Figs. 2 and 3 are enlarged sectional views along the lines II-II and III-III in Fig. 1, Fig. 4 is a modification of the waveform shown in the sectional view of Fig. 3, and Fig. 5 and 6 are plane views corresponding to the sectional views shown in Fig. 3 and 4, respectively. In the embodiments shown in the drawing, the flashing material according to the invention consists of aluminium foil preferably having a thickness between 0.05 and 0.4 mm, eg. 0.1 mm, shaped in the form of a ribbon or a strip 1 with a width of eg. 15-20 cm to be fastened to a conventional roof window as explained eg. in the applicant's DK patent no. 151.112. According to the invention, this foil material is corrugated in a continuous waveform in two directions orthogonal to each other by two consecutive rolling operations in the directions shown by the arrows A and B in Fig. 1. By the first rolling operation in the direction A which is preferably the cross direction of the ribbon or the strip 1, the material in the shown embodiments is corrugated in a continuous waveform with substantial- ly S-shaped waves with wave crests 2 as shown in Fig. 2 when passing through one or more section rolling stations. The subsequent rolling in the direction B which is preferably the longitudinal direction of the ribbon 1, may be performed in the same or a corresponding rolling installation, ie. with the same form of wave profile with wave crests 3 as shown in Fig. 3. A possible cold setting caused by one or both rolling operations is relatively easily removed by annealing. However, the corrugation in the two rolling operations need not be the same. Thus, as eg. shown in Fig. 4, an asymmetrical waveform with another amplitude and wavelength than in the first rolling operation can be provided in the second rolling operation. By the shown embodiments, the ribbon- or strip- shaped material is, prior to the rolling operations, folded along a folding line 4 substantially halfway between the two opposite long sides of the ribbon in such a way that the folded flashing will comprise two folded up foil layers 5 and 6, as it appears from Figs. 2-4. In the first place, a completely closed free lower edge at the folding line is thus obtained for a strip-shaped flashing of a roof window. Secondly, the manual deformability appeared to be improved by using the two relatively thin folded up foil layers instead of one layer with the double thickness. Furthermore, it appeared that such a folded flashing material is practically free from resilience and can thus be brought into quite close abutment with the surrounding roofing independently of its surface form. As the corrugation causes a certain locking effect between the two folded up foil layers 5 and 6 in connection with the forming of the flashing against the roofing, an improved stiffness is further obtained. In particular, the second rolling operation results in an efficient lock between the foil layers, as the wave crests are deformed in the rolling direction such that the foil layers are backfolded at one end of the wave crest marked by 8 in Figs. 3 and 4. As shown in Fig. 4, an intermediate layer 7 can be placed between the two folded up foil layers 5 and 6. Such an intermediate layer may be an aluminium foil with the same or another thickness than the layers 5 and 6 or it may be of a completely different material, eg. an adhesive or non-adhesive thermoplastic material. The flashing material according to the invention can hereby be manufactured with the required properties as to eg. strength, deformability and weight. The finished flashing material may be applied with lacquer in a usual manner or coated in another way in order to obtain an improved weatherproofness and eg. chromatic adaptation to the surroundings.

Claims: C L A I M S 1. A deformable sheet material for roof flashing purposes in connection with roof windows and similar roof penetrating building structures consisting at least partly of a metal sheet or a metal foil which has been corrugated in a continuous waveform, characterized in that the material is corrugated in a continuous waveform in two directions (A, B) substantially orthogonal to each other. 2. A sheet material according to claim 1 and designed as a ribbon or a strip, one long side of which is intended for connection with the roof penetrating building structure, characterized in that prior to said corrugation in waveform, the ribbon or strip is folded in the longitudinal direction along a folding line (4) placed substantially halfway between the two opposite long sides. 3. A sheet material according to claim 2, charac¬ terized in that an intermediate layer (7) is placed between the two material layers (5, 6) in the folded sheet material in order to obtain improved strength or deformation properties or increased weight. 4. A sheet material according to claim 1, 2 or 3, characterized in that the waveforms in the two direc- tions substantially orthogonal to each other possess substantially the same amplitude and wavelength (Fig. 2, 3) . 5. A sheet material according to claim 1, 2 or 3, characterized in that the waveform in one of the two directions is asymmetrical and different from the waveform in the other direction (Fig. 4) . 6. A sheet material according to any of the foregoing claims characterized in that it consists of aluminium foil. 7. A sheet material according to any of the foregoing claims characterized in that said sheet or foil has a thickness between 0.05 - 0.4 mm. 8. A sheet material according to claim 3 and 6, characterized in that said intermediate layer (7) also consists of aluminium foil. 9. A sheet material according to any of the foregoing claims characterized in that it is provided with a weatherproof and/or chromatic adapting surface coating. 10. A method of manufacturing a sheet material accor¬ ding to any of the foregoing claims characterized in that after rolling in a first direction (A) for produc¬ tion of a first continuous waveform, a ribbon or a strip (1) consisting at least partly of metal sheet or metal foil is corrugated in a second waveform substantially orthogonal to the first by rolling in a second direction (B) substantially orthogonal to said first direction. 11. A method of manufacturing according to claim 10, characterized in that said ribbon or strip is, prior to said rolling operation, folded in its longitudinal direction along a folding line (4) substantially halfway between the two opposite long sides. 12. A method of manufacturing according to claim 10 or 11, characterized in that an intermediate layer (7) is placed between the two material layers (5, 6) in said folded ribbon or strip in order to obtain an improved strength or deformation properties or increased weight.

Inventors: ANDERSEN SUSANNE BJERGEGAARD, JACOBSEN PER, ANDERSEN, SUSANNE, BJERGEGAARD, JACOBSEN, PER
Applicants: ANDERSEN SUSANNE BJERGEGAARD, JACOBSEN PER, RASMUSSEN KANN IND AS, ANDERSEN, SUSANNE, BJERGEGAARD, JACOBSEN, PER, V. KANN RASMUSSEN INDUSTRI A/S
Application year: 1995
Main classification: E04D13
IPC codes: E04D3, E04D13