WO2003016652A1

WO2003016652A1 - Sub-structure for a roof or a facade

Info

Publication number: WO2003016652A1
Application number: PCT/EP2002/009111
Authority: WO
Inventors: Karl Friedrich Fick; Christian Flertmann
Original assignee: Corus Bausysteme Gmbh
Priority date: 2001-08-15
Filing date: 2002-08-09
Publication date: 2003-02-27
Also published as: GB2392681A; GB0400908D0; AT500406B1; DE20280423U1; AT500406B8; CH696323A5; DE10297074T5; WO2003016652A8; GB2392681B; AT500406A2

Abstract

The invention relates to a sub-structure for mounting on a support structure (1) together forming part of a roof or a facade structure of a building, comprising a heat insulating layer (2) arranged on the support structure (1), and elongate spacer sections (3, 4) on the heat insulating layer (2) and whereby the elongate spacer sections (3, 4) are for connecting to the support structure (1) by means of spaced connection elements (12) and for holding retaining elements (5) for building sheets (9), wherein the elongate spacer sections (3, 4) are formed by rigid sheets having multiple anchoring means (6, 7) essentially perpendicular to the direction of elongation of the rigid sheet and facing towards the support structure for anchoring the rigid sheet onto the heat insulating layer (2), and wherein on top of the heat insulating layer (2) and between the building sheets (9) and the retaining elements (5) there is arranged a further layer (11) of heat insulating material of lower density than the first heat insulating layer (2). The invention further relates to an assembly of at least one such sub-structure mounted on at least one support structure, thereby forming part of a roof or a facade structure.

Description

SUB-STRUCTURE FOR A ROOF OR A FACADE

The invention relates to a sub-structure for mounting on a support structure together forming part of a roof or facade structure of a building, comprising a heat insulating layer arranged on the support structure and elongate spacer sections for connecting to the support structure by means of spaced connection elements and for holding or mounting retaining elements for building sheets. The invention further relates to an assembly of at least one such sub-structure mounted on at least one support structure, thereby forming part of a roof or a facade structure. Such a sub-structure for a roof is known from European application no. EP-

0685612-A1, where the support structure is typically formed by an old roof under repair or renovation, e.g. a trapezoidal sheet roof structure or a wooden structure with for example wooden barriers. On top of the support structure there is provided a thin barrier layer against moisture and air, typically formed by a foil or the like, and on this thin barrier layer there is provided a relatively thick layer of tread-proof fibre heat insulating layer, e.g. high-density mineral wool. In order to allow the subsequent mounting of retaining elements for holding building sheets forming the new outside of the roof or the facade, load bearing elongate spacer sections are provided on top of the insulating layer for mounting such retaining elements. According to EP-0685612-A1 these load bearing elongated spacer sections are formed by longitudinal U-shaped profiles of metal, the web of which forms the securing base or mounting base for the retaining elements, the web typically has a width of about 60 mm, and further having two arms extending substantially perpendicular to the web into the heat insulating layer typically over a distance of about 20 mm. To achieve a reliable and durable positioning of the elongate spacer sections with respect to the support structure, the elongate spacer sections are secured by means of spaced-apart long connecting elements, e.g. thread screws of stainless steel, which pass through the web of the elongate spacer sections, through the tread-proof heat insulating layer and into the support structure. Prior to mounting the retaining elements onto the elongate spacers sections, the elongate spacer sections need to be carefully located with respect to the support structure, and furthermore the elongate spacer sections need to be sunk into the tread-proof thermal insulating layer. For the latter purpose by using a special device, tracks for the two arms of the U-shaped elongate spacer sections are being milled into the tread-proof heat insulating layer. Thereafter the U-shaped spacer sections are located into these milled tracks and connected to the support structure by means of long threaded screws.

A disadvantage of this sub-structure is that it requires the cutting or milling of the tracks for the U-shaped elongate spacer sections, which cutting or milling requires in turn dedicated equipment and skilled labour force. A further disadvantage is the difficulty of the cutting or milling of the tracks in the event of roof structure having a steep inclination or on a facade structure.

It is an object of the invention to provide a sub-structure for a roof or a facade and which is easier to construct. It is another object of the invention to provide a sub-structure having an improved thermal barrier.

According to one aspect of the invention, there is provided a sub-structure for mounting on a support structure, whereby the sub-structure and support structure together form part of a roof or a facade structure of a building, the sub-structure comprising a heat insulating layer arranged on top of the support structure, and load bearing elongate spacer sections on said heat insulating layer and whereby the elongate spacer sections are for connecting to the support structure usually by means of spaced connection elements such as screws securing the spacer sections to the support structure and in addition for holding or mounting retaining elements for the building sheets. The sub-structure is characterised in that the elongate spacer sections are formed by rigid sheets or rigid strips having multiple anchoring means, typically located at spaced intervals, and essentially perpendicular to the direction of elongation of the rigid sheet and facing towards the support structure for anchoring the rigid sheet onto the underlying heat insulating layer, and wherein on top of the underlying heat insulating layer and between the building sheets and the retaining elements there is arranged a further layer of heat insulating material of lower density than the first underlying heat insulating layer.

This achieves the effect that the elongate spacer elements formed by the rigid sheets or strips can be positioned in a very easy manner just by placing the rigid sheet or strip on top of the underlying heat insulating layer, after which for example by the weight of a person the multiple anchoring means are forced into the heat insulating layer for positioning the rigid sheets. Consequently, the sub-structure is much easier to construct as compared to the prior art. Furthermore, the need for a special device for milling tracks into the underlying heat insulating layer has been overcome. Also the relocation or anew placement of a spacer element in case of for example a small positioning error has become much easier since such a rigid sheet can be taken out of the underlying heat insulating layer without any difficulty. After the removal of such a rigid sheet in accordance with the invention there remains no damages with the underlying heat insulating layer apart from a few minor and very small holes, whereas in the sub-structure according to the prior art, the milled elongate tracks remain permanent in the underlying tread-proof heat insulating layer and can't be removed. Furthermore, the application of two heat insulation layers of different densities in the present arrangement achieves the effect of a cheaper roof or facade structure, while achieving a significantly improved thermal insulation efficiency. Tread-proof thermal insulating material, usually formed by a high-density mineral wool, are relatively expensive and have a lower thermal isolation capacity compared to more conventional heat insulating material of lesser density. It is now possible to keep the first underlying layer of tread-proof material relatively thin and thereby keeping costs relatively low, while the second layer can be made thicker than the first layer, thereby improving the thermal isolation capacity of the whole sub-structure. Furthermore, the material selected for the second insulating layer is much more flexible and more easy to handle than the more rigid first underlying heat insulating layer material. In addition, the application of such a second thermal insulation layer achieves the effect that the elongate spacer sections themselves are isolated thermally also and thereby act much lesser as a undesirable thermal bridge compared to spacer sections according to the prior art substructure laying directly underneath the outer building sheets. In an embodiment the multiple anchoring means are being formed by elongate protrusions formed by for example nails, screws or the like fixed to the rigid sheet, for example by means of mechanical fastening, adhesion, soldering or butt welding.

In an embodiment the multiple anchoring means are being formed by lugs from the rigid sheet and which are cut into said rigid sheet itself and extend outwardly thereof. Such lugs have preferably a relatively sharp shape, such as a triangular shark teeth shape, to facilitate the penetration into an underlying tread-proof heat insulating layer. The lugs can be pre-cut into the rigid sheet and are preferably being pushed outwardly by simple mechanical tools firstly on the construction site.

The load bearing rigid sheet or strip may be formed from various materials, but in a preferred embodiment the rigid sheet is formed from a metal sheet such as a steel sheet, preferably from a galvanised steel sheet. Galvanised steel sheets are a known and accepted construction material, having a high strength and a good resistance against corrosion.

In an embodiment the load bearing rigid sheet has a width in a range of 90 to 300 mm, and preferably in the range of 120 to 200 mm. In this way the connecting elements such as long screws for coupling the rigid sheet to the support structure, may the positioned near the edges of the rigid sheet. Preferably the connecting elements are positioned in at least two rows at spaced intervals essentially parallel to, but away from the centreline of the rigid sheet and wherein the connecting elements in the parallel rows are at leaped positions with respect to each other along the direction of elongation of the rigid sheet. In this way the resistance against torsion of the rigid sheet is being further improved. In the prior art sub-structure the connecting elements are positioned across the centreline of the U-shaped elongate profile, the heads of the screws are thereby hindering and limiting the positioning of retaining elements for the building sheet onto the rigid spacer section. For that reason in the prior art sub-structure mainly countersunk screws are being used, their application being very labour intensive. The need to apply such countersunk screws has been overcome in the arrangement according to the invention. Furthermore, such known arrangement for positioning the countersunk screws may form an undesirable hinge-moment for the U-shaped elongate profile. In accordance with the invention the centreline area of the rigid sheet can be kept free from any kind of obstacles, and thereby increasing the freedom of positioning further elements such as the mounting of retaining elements, and significantly reducing the formation of an undesirable hinge-moment.

According to the invention in another aspect, there is provided an assembly of at least such a sub-structure mounted on at least one support structure, thereby forming part of a roof or a facade structure. According to the invention is another aspect, there is provide a load bearing rigid sheet, typically a metal sheet as elongate spacer section, and provided with pre-cut parts able to form the lugs for penetrating into heat insulating layer of a sub-structure. The rigid sheet is preferably a metal sheet, more preferably a galvanised steel sheet.

The invention will now be illustrated by discussing the prior art and several non- limitative embodiments, with reference to the accompanying drawings, in which:-

Fig. 1 shows a schematic perspective view of a sub-structure according to the prior art;

Fig. 2A to 2D show a schematic perspective view of part of a load bearing elongate spacer sections according to the invention;

Fig. 3 shows a schematic view of a sub-structure in accordance with the invention; Fig. 4 shows a schematic top view of a sub-structure in accordance with the invention;

Fig. 1 shows schematically a sub-structure according to the prior art as known from European patent application EP-0685612-A1, comprising a support structure 1 formed by a trapezoidal sheet roof structure, a thin moisture and air barrier layer 8, a relatively thick layer 2 of tread-proof high-density mineral wool for heat insulating purposes, and two load bearing elongate spacer sections 3,4 which are formed by U- shaped elongate metal profiles with a web having a width of about 60 mm. The two arms of the U-shaped profiles extend substantially perpendicular to the web into the heat insulating layer 2 and fixate the U-shaped profiles 3,4 with respect to the insulating layer. The U-shaped profiles 3,4 are secured to the support structure 1 by means of long countersunk thread screws located at spaced intervals along the centreline of the web of the U-shape. On top of the web of the U-profiles there may be mounted retaining elements for holding building sheets forming e.g. a standing-seam roof structure or alternatively a trapezoidal sheet roof 9 may be connected to the spacer sections. Fig. 2A shows schematically a part of a load bearing elongate spacer sections formed by a rigid sheet 3, such as a metal sheet, having cut sections which can form the lug 7 as one of the multiple anchoring means. Fig. 2B shows schematically the lug 7 extending essentially perpendicular to the direction of elongation of the rigid sheet. In the upright position of the lug 7 there is left a hole 10 in the rigid sheet 3. The lug 7 can be cut into the rigid sheet by known technical means. In the shown embodiment the lug has a square shape, but it will be immediately apparent for the skilled person that it can also be formed by a in cross section triangular shape, such as a shark-teeth shape, as shown in Fig. 2C, or the like for more ease of penetration into the high-density heat insulating layer. Fig. 2D shows the embodiment where the anchoring means are formed by protrusions 6, such as nails or screws positioned at spaced intervals on the rigid sheet and connected to said rigid sheet or strip for example by means of adhesion or (butt-) welding. A combination of the anchoring means as shown in Fig. 2B and/or 2C with those shown in Fig. 2D is possible.

Fig. 3 shows a schematic cross-sectional view of the sub-structure in accordance with the invention and which has been arranged on a support structure 1 formed by an existing trapezoidal sheet roof structure 1. On top of a spacer section formed by the rigid sheet 3 there are provided retaining elements 5 for holding building sheets 9. The rigid sheet 3 is provided with nails 6 as anchoring means on top of an underlying heat insulating layer 2, typically a tread-proof high-density mineral wool material, in turn arranged on top of a thin barrier layer 8. On top of the first underlying insulating layer 2 and between the building sheets 9 and the retaining elements 11 mounted on the rigid sheet 3 there is provided a second layer 11 of heat insulating material having a lower density then the first layer 2, and thereby providing an improved heat insulating efficiency of the whole sub-structure. Further advantages have been set out above.

Fig. 4 shows a schematic top view of the sub-structure in accordance with the invention. The load bearing pacer elements are formed by the rigid sheets 3,4 and which are arranged on top of an insulating layer (not shown) with lugs (not shown). On top of the rigid sheets 3,4 there are provided at spaced intervals retaining elements 5, such as for example those known from DE-3442398, DE-3442407, and EP-0983409, all incorporated herein by reference, for holding building sheets forming a standing-seam roof structure 9. The connecting elements 12 such as long screws are being aligned in the direction of elongation of the rigid load bearing sheet relatively close to the edges of said rigid sheet. The two essentially parallel rows of connecting elements 12 on each rigid sheet are arranged such that they leap with respect to each other. The distance between two neighbouring rigid sheet may vary on the roof structure, but would typically be in the range of 800 to 3000 mm. The advantages of such an arrangement have been set out above.

Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made without departing from the spirit or scope of the invention as herein described.

Claims

1. Sub-structure for mounting on a support structure (1) together forming part of a roof or a facade structure of a building, comprising a heat insulating layer (2) arranged on the support structure (1), and elongate spacer sections (3,4) on the heat insulating layer (2) and whereby the elongate spacer sections (3,4) are for connecting to the support structure (1) by means of spaced connection elements (12) and for holding retaining elements (5) for building sheets (9), characterised in that, the elongate spacer sections (3,4) are formed by rigid sheets having multiple anchoring means (6,7) essentially perpendicular to the direction of elongation of the rigid sheet and facing towards the support structure for anchoring the rigid sheet onto the heat insulating layer (2), and wherein on top of the heat insulating layer (2) and between the building sheets (9) and the retaining elements (5) there is arranged a further layer (11) of heat insulating material of lower density than the first heat insulating layer (2).

2. Sub-structure according to claim 1, wherein the anchoring means are formed by lugs (7) from the rigid sheet and extending outwardly thereof.

3. Sub-structure according to claim 1, wherein the anchoring means are formed by elongate protrusions (6) connected to the rigid sheet.

4. Sub-structure according to any one of claims 1 to 3, wherein the connecting elements (12) are arranged at spaced intervals across at least two essentially parallel rows along the direction of elongation of the rigid sheet (3,4).

5. Building having a roof or a facade with a sub-structure as defined in any one of claims 1 to 4.

6. Load bearing rigid metal sheet having multiple lugs (7) or elongate protrusions (6) as defined in any one of claims 1 to 3 as elongate spacer section (3,4) for penetrating into a heat insulating layer of a roof structure of a building.