Patent Application
20090293375
The arrangement relates to an arrangement for a roof or a façade of a building, comprising a thermal insulation layer and a counter-batten system made up of a plurality of counter-battens and provided above the thermal insulation layer.
Arrangements of the type in question can take the form of roof arrangements or façade arrangements. In the case of a roof arrangement, it is conventional for there to be provided a plurality of rafters on which a roof covering is situated. Apart from the aforementioned insulation layer and the counter-batten system, the roof covering conventionally comprises a tiling batten system made up of a plurality of tiling battens and roof tiles. Also known besides, however, are roof arrangements which manage without rafters. The substructure in that case is formed by a concrete slab to which the thermal insulation layer is conventionally applied by means of a counter-batten system. Facade arrangements substantially correspond to the roof arrangements; however, instead of a plurality of rafters, vertical members which are conventionally made of wood or wood-based materials, but may also be made of concrete, are provided. The thermal insulation layer is then applied thereto. Of course, it is also possible in the case of façades to provide concrete slabs instead of a corresponding system of vertical members, the thermal insulation layer then being applied to these slabs. The thermal insulation layer is conventionally likewise fastened via a counter-batten system; however, a roof tiling batten system is then not required.
The statements which follow refer in their entirety to roof arrangements only. It goes without saying, however, that these statements apply equally well to façade arrangements without any specific reference thereto being required.
What is important in roof arrangements of the type in question is that they have adequate thermal insulation. This applies both to new buildings and to roof renovations.
In a known roof arrangement, an insulating material is provided between the rafters. Above the rafters and the insulating material is situated a watertight layer of underlay sheets. This layer is held on the rafters via counter-battens. Above the counter-battens and extending at a right angle thereto are conventionally situated tiling battens which are fastened to the counter-battens. In this known roof arrangement, considerable heat losses occur in the region of the rafters as the result of thermal bridges. A thermal bridge in the present case is to be understood as meaning a continuous region of significantly higher thermal conductivity than the insulating material. Wood has, for example, a very much higher thermal conductivity than the insulating material, which means that the rafters constitute potential risk points for thermal bridges. A thermal bridge in the present case is also to be understood as meaning points at which the counter-battens lie on top of the rafters with a thin underlay sheet placed in between. On cold days, the room-side surface temperature drops in the region of these thermal bridges. When the temperature falls below the dew point temperature, this can result in condensation and mould formation. Moreover, thermal bridges additionally entail a high heat requirement for heating purposes.
To improve the thermal insulation particularly when renovating old roof arrangements, a procedure has in some cases been adopted in which the rafters are doubled up so as to obtain an increased rafter height and hence an additional space between the rafters for arranging supplementary insulating material. Over the doubled-up rafters is then arranged a layer of underlay sheets. If appropriate, boarding made of wood-based materials may be provided between the rafters and the underlay sheets. The counter-batten system and tiling batten system are then mounted. As a result of the additional insulating material, the thermal insulation of this roof arrangement is improved. However, thermal bridges with the above-described disadvantages still result in the region of the doubled-up rafters.
In another known roof arrangement, a so-called over-rafter insulation is provided for renovation purposes. Here, hard panels of PUR or PS are applied to the rafters and to the thermal insulation situated in between. As an alternative to this, it is also possible to apply wood fibreboard panels to the rafters. The thermal bridges in the region of the rafters are substantially avoided through the aforementioned measures. However, the aforementioned panels are associated with various disadvantages. The wood fibreboard panels are not only expensive but also decidedly heavy, which makes them difficult to handle and lay. The insulating material panels, although lighter than the wood fibreboard panels, are even more expensive than the wood fibreboard panels. Since the items in question are piece goods, the laying operation is complicated in this case too. Regardless of the type of panels, however, it is the case with these known roof arrangements that a layer of underlay sheets is conventionally applied to the panels in order to be able to ensure watertightness. This is associated with additional effort and cost. Moreover, it is the case with all the known roof arrangements that a large number of joints occur, a situation which has an unfavourable impact on the thermal insulation. In this respect, joints are provided not only in the case of roof arrangements having insulating panels, between which the joints are situated, but also in the case of doubled-up rafters and the material additionally introduced in the enlarged space between the rafters.
The present invention provides a roof arrangement of the type mentioned at the outset which offers good thermal insulation while avoiding thermal bridges, is cost-effective and can be laid easily.
According to the invention, in the case of a roof arrangement of the type mentioned at the outset the thermal insulation layer comprises at least one composite sheet laid from a roll, and the composite sheet is formed in at least two layers with an underlay sheet and an insulating material sheet connected to the underlay sheet.
The invention offers a series of key advantages. First and foremost, the composite sheet according to the invention performs a dual function. On the one hand, it has the function of an underlay sheet known from the prior art and on the other hand a thermal insulation function as a result of the insulating material sheet. Apart from this dual function, the invention is noteworthy in that provision is made for the composite sheet to be laid from the roll. This facilitates the laying operation quite considerably since the composite sheet can be unrolled from the roll and laid over and beyond the rafters and other rising components in a problem-free manner. In the case of a roof arrangement having rafters, the individual composite sheets are preferably arranged transversely with respect to the rafters. What is meant here by the transverse arrangement of the composite sheet with respect to the rafters is that the composite sheet is laid at an angle to the rafters. This arrangement can of course also be provided if additional wood boarding is situated on the rafters. Should the roof arrangement have a concrete slab as the substructure, the arrangement of the composite sheet is not an issue. The same also applies in principle to a façade arrangement. Moreover, a further advantage of the present invention lies in the fact that, since the composite sheet used is rolled from the roll, significantly fewer joints are provided in the thermal insulation layer than is the case in the prior art. This has a correspondingly positive impact on the thermal insulation. It should be additionally noted in connection with the thermal insulation that, because the sheet is laid over and beyond the rafters, no disadvantageous thermal bridges result in the region of the rafters, or else thermal bridges are considerably reduced. In addition, the composite sheet according to the invention is also very light due to its weight, which means that it can be transported to a roof and handled there without problems.
To make it possible for the composite sheet to be laid from the roll in a simple manner, provision is made according to the invention for the insulating material of the insulating material sheet to be compressible and flexible. The insulating material should preferably be a polyester fibre nonwoven, glass wool and/or mineral wool. To achieve adequate thermal insulation, the thermal insulation sheets here should have a thickness of more than 1 cm, preferably between 2 and 8 cm and in particular of about 3 cm. It has been found that, in order to achieve good thermal insulation, a thermal conductivity of between 0.025 and 0.05 W/(m·K) and preferably between 0.03 and 0.04 W/(m·K) should be provided for the sheet when it is in the non-compressed state, this generally being ensured with the aforementioned thicknesses of the insulating material sheet.
The counter-battens known from the prior art serve to fasten the composite sheet. These are fixedly connected, in particular nailed and/or screwed, to the rafters, with the composite sheet being placed in between. In the process, the composite sheet is then compressed in the region of the counter-battens. It has been found that the thermal conductivity in the region where the composite sheet is compressed is lowered as a result of the compression, specifically to values of between 0.02 to 0.045 W/(m·K) and in particular 0.025 to 0.035 W/(m·K). Owing to the thermal conductivity being lowered in this region, very good thermal insulation is obtained while avoiding thermal bridges. Nowhere near such a low conductivity can be achieved if, as provided in the prior art, only an underlay sheet is situated between the rafters and the counter-battens.
Since the insulating material of the insulating material sheet is compressible and flexible, the composite sheet can be rolled up in a highly space-saving manner, which means that even comparatively long sheets can be carried onto a roof and handled there in a simple manner. With the thickness dimensions indicated above, the length of a composite sheet can be greater than 3 m, preferably greater than 5 m and in particular about 10 m. The width of the composite sheet can be chosen freely per se and is preferably greater than 50 cm. Preferably, the width is between 1 and 2 m and in particular about 1.5 m.
To achieve good thermal insulation, it is necessary to use an adequate amount of insulating material. It has been found that the weight of the composite sheet according to the invention should be greater than 300 g/m2, in particular between 500 and 2000 g/m2 and preferably about 1000 g/m2.
As has as already been stated above, the counter-battens serve for fastening the composite sheet to the rafters. In the configuration according to the invention, provision is made for the height of the counter-battens to be greater than the thickness of the composite sheet. It is ensured in this way that, even when the composite sheet is highly compressed by the counter-battens, the tiling batten system provided on the counter-batten system is raised from the water-guiding plane of the underlay sheet. In this case, the height of the counter-battens is usually 2 cm to 4 cm higher than the thickness of the composite sheet, deducting the compressed thickness of the composite sheet in the region of the fastened counter-battens. Thus, the height of the counter-battens can be about 4 cm for example when the composite sheet has a thickness of 3 cm.
As already mentioned above, the counter-battens are conventionally fastened to the rafters by means of screws and/or nails. To prevent the ingress of water at these connection points, provision is made in a preferred configuration of the invention for a sealing tape to be arranged between the counter-battens and the underlay sheet.
To facilitate the laying operation, the sealing tape has an adhesive coating on at least one side. This makes it possible for the sealing tape to be fastened to the underside of a counter-batten in a simple manner before this counter-batten is fastened to the associated rafter, with the composite sheet being placed in between. It is also expedient in this respect for the width of the sealing tape to correspond at least substantially to the width of the rafter.
The underlay sheet of the composite sheet according to the invention should preferably be diffusion-open and watertight. For this purpose, the underlay sheet can be formed as a nonwoven, in particular of PES, with an external watertight and diffusion-open coating, in particular of PU. The Sd value can be between 0.01 and 0.4 m, preferably between 0.02 and 0.3 m and more preferably between 0.15 and 0.25 m. Moreover, it goes without saying that the underlay sheet can also be produced from other materials in which comparable Sd values are possible. Thus, the underlay sheet can, for example, be composed of two polypropylene spunbonded nonwovens having a breathable film of PE or PP. It is also possible to provide a PES or PP spunbonded nonwoven having a breathable acrylate-based coating. Ultimately, a large number of different possibilities are available for the underlay sheet.
To enable the composite sheet according to the invention to be cut to size easily and exactly, the underlay sheet has an embossed grid pattern on its upper side. For this purpose, the embossed grid pattern comprises parallel embossed strips extending in the longitudinal direction of the composite sheet and transversely thereto.
To obtain a watertight and windtight thermal insulation layer, the width of the underlay sheet is greater than the width of the insulating material sheet. This means that the underlay sheet projects at least on one longitudinal side beyond the insulating material sheet by way of a longitudinal edge. An adhesive edge is then preferably provided on the underside of the at least one longitudinal edge projecting beyond the insulating material sheet. With a plurality of composite sheets which are laid parallel to one another and which should preferably be laid parallel to the eaves, the insulating material sheets of adjacent composite sheets butt tightly against one another with the result that they are substantially free from gaps. The flush and substantially gap-free butt-jointing of adjacent composite sheets results particularly from the fact that the insulating material of the individual insulating material sheets is compressible and flexible and from the fact that the insulating material sheets of adjacent composite sheets can hug one another firmly. On the upper side, the edge of the underlay sheet lies on top of the adjacent composite sheet and is adhesively bonded to it via the adhesive edge, where this is present. It should also preferably be the case here that the projecting longitudinal edge of an upper composite sheet lies on top of the underlay sheet of a lower laid composite sheet and is adhesively bonded thereto. It is ensured in this way that water running off cannot reach the adhesive bond of the adhesive edge.
Furthermore, the composite sheet according to the invention also offers the possibility of being secured to the eaves in a simple manner. Provision is made for this purpose for the lower composite sheet adjacent to the eaves to be laid with the insulating material sheet against an eaves fillet, while the underlay sheet is laid on top of the eaves fillet and adhesively bonded there by means of the adhesive edge. Water running off over the underlay sheet can thus be guided over and beyond the eaves fillet into a rainwater gutter.
In addition, the present invention also relates to a composite sheet of the aforementioned type for the roof arrangement described. The composite sheet here can have all the aforementioned features per se or in any combination.
Exemplary embodiments of the invention will be explained below with reference to the drawing, in which:
The individual figures each show an arrangement or details of the arrangement 1 for a roof 2 of a building 3. The arrangement 1 comprises a plurality of rafters 4 which in the present case extend vertically from the ridge 5 to the eaves 6 and are arranged parallel to one another. In addition, a roof covering 7 is situated on the rafters 4. The roof covering 7 comprises in the present case a thermal insulation layer 8, a counter-batten system made of a plurality of counter-battens 9 and provided above the thermal insulation layer 8, a tiling batten system made up of a plurality of tiling battens 10 and provided above the counter-batten system, and roof tiles 11′ placed on the tiling batten system.
Provision is now made for the thermal insulation layer 8 to comprise at least one composite sheet 12 which is laid from the roll 11 and extends transversely with respect to the rafters, this sheet being formed in at least two layers with an underlay sheet 13 and an insulating material sheet 14 connected to the underlay sheet 13. The laying operation from the roll 11 is represented schematically in
In the exemplary embodiment represented, the insulating material sheet 14 has a thickness of about 3 cm. Here, the composite sheet 12 then has a thermal conductivity value of 0.04 W/(m·K) to EN12667 in the non-compressed state, while the thermal conductivity value of the composite sheet 12 in the compressed state, as is represented in
As can be seen from
The underlay sheet 13 of the composite sheet 12 is watertight and diffusion-open. In the present case, the underlay sheet 13 is a nonwoven layer of PE with an external watertight and diffusion-open coating of PU. The Sd value is approximately 0.18 m. A watertightness W 1 to EN13859-1 is provided. On its upper side, the underlay sheet 13 has an embossed grid pattern (not shown) so that the composite sheet 12 can be severed more easily or more exactly in the longitudinal direction of the counter-battens 9 or the tiling battens 10.
As illustrated particularly in
To secure adjacent composite sheets 12 in a row, various possibilities are available, of which two are represented in
In the embodiment represented in
Both
| Number | Date | Country | Kind |
|---|---|---|---|
| 20 2008 007 332.4 | Jun 2008 | DE | national |
