Insulation system comprising interconnected insulations panels disposed against a wall

The invention concerns a wall system as described in the preamble of claim 1 and a method for installing such a wall system.

This type of wall systems is known from DE 101 47 831 A1, describing a wall with C-profiles as the load-bearing construction and insulation panels arranged between the C-profiles. Covering layers such as plasterboards are mounted on both sides of the wall. The insulation layer is thicker than the distance between the two flanges of the C-profile. Therefore, the covering layer on one side of the wall is fixed directly to one flange of the C-profile, while the cover layer on the other side is placed against the insulation layer and fixed to the other flange of the C-profile by screws extending through the insulation. This type of construction reduces the heat loss through thermal bridges and improves the sound reduction slightly compared to a traditional construction where the C-profile extends from one cover layer to the other.

Such a wall system, however, still has the significant disadvantage of a considerable number of screws. These screws together with the C-profile to which they are attached will still transport a significant amount of heat energy from one side of the wall system to the other and thereby reduce the heat insulating capacity of the wall. Also the sound insulating capacity is reduced.

This problem has been solved by the present invention by arranging the wall system as described in the characterising part of claim 1. Thereby the wall system comprises two individual walls placed next to each other and secured individually to the rest of the building construction. The two individual walls may be placed closely together and may be fitted together by use of an adhesive, or there may be a small air gap ensuring ventilation. This will often be necessary when the wall is an outer wall where the temperature difference may be relatively high, increasing the risk of condensation of vapour.

The wall system according to the invention comprises a building wall with an insulation layer, said building wall being the façade wall of a building or an inner wall and the insulation layer comprises insulation panels. The insulation panels have two substantially parallel major surfaces and minor surfaces connecting the major surfaces. The insulation panel is positioned between at least two profiles where each profile has a base portion substantially parallel with and in contact with a part of one minor edge surface of the insulation panel. Means for engaging the insulation panels and holding them in position are arranged in connection with the base portion of the profile. The insulation panel has a thickness larger than the width of the base portion of the profiles.

At least one profile is arranged and fastened to parts of the building different from the building wall in such way that no single element or combination of elements except the insulation panels themselves extends from a plane formed by the major surfaces facing the inside of the building to a plane formed by the major surfaces of the insulation panels facing the outer wall.

Preferably, a slit is made in a minor surface and extending substantially parallel with the major surfaces of the insulation panels. Preferably, the profile is provided with a flange portion substantially parallel with the major surfaces of the insulation panel.

The profiles are arranged and fastened so that practically no parts will span from one major surface to the opposite major surface of the insulation panels and the building wall is not directly connected with the major surface of the insulation panels opposite the building walls, by mechanical means other than possibly part of the heat insulating layer.

One further advantage of this new wall system is that the two parts of the wall system can be installed independently from each other, which means that the system is suitable for renovation projects and improvements of the insulation performance of a building. E.g. an existing non-insulated façade wall can be used as the first outer wall part, i.e. the building wall, in the new wall system, and the second part comprising the insulation can be installed independently.

To achieve this new wall system with two independent wall parts, the inner part of the wall system comprising the insulation could be secured to the ceiling, roof and/or wall construction and not to the outer building wall other than by the insulation material, possibly with some adhesive.

The advantages of this wall system is that there is no thermal bridging nor elements suitable for transporting sound from one side of the wall to the other. This means that both improved heat and sound insulation can be achieved. Also, the fire properties will be improved with the wall system according to the invention, as the heat from a fire starting at the building wall side of the insulation will be insulated from the profiles, and therefore these will be affected and e.g. starting bending at a later stage of the fire. This will delay the fire break through of the second wall part comprising the insulation layer.

The profiles will extend a distance of maximum 85% of the thickness of the insulation layer, preferably a maximum of 75%, and even more preferably a maximum of 60%. Obviously, this distance will depend on the thickness of the insulation layer. If the profiles extend 75% of a 100 mm thick insulation layer, the same profile will only extend 37.5% of a 200 mm thick insulation layer. The profiles are preferably made of metal, preferably steel or aluminium. Perforations in the profiles in order to reduce the heat conductivity could be advantageous. The profiles could also be made from a material having lower heat conductivity than metal e.g. plastic or wood. Also a combination of different materials is a possibility.

The insulation material used in the new wall system may be any known insulation material such as fibrous or foam or plastic based materials. Mineral fibre insulation such as glass wool or stone wool is particularly useful due to the better fire properties. Especially stone wool provides very good fire properties and has also good acoustic properties. Mineral wool will also offer an easier installation as these products are more flexible than e.g. foam insulation.

This new wall system can be used for refurbishments of existing buildings, for new buildings and also for prefabricated façade elements.

In a first embodiment the wall system is made as an outer wall where the first part of the wall without insulation is the outer building wall part, typically made of bricks and/or concrete, also being the façade of the building. Often there will be an air gap between the two parts of the wall. The second part, often being the inner wall part, comprises the insulation placed in a framework of profiles. Each insulation panel has four minor surfaces where a slit extending substantially parallel with the major surfaces is made in at least one minor surface. The insulation panels are each placed between at least two profiles. Each profile has a base portion being substantially parallel with and in contact with one minor surface of the insulation panel and one flange portion being substantially parallel with the major surfaces of the insulation panel and extending into said slit in a minor surface of the insulation panel. The insulation panels have thicknesses larger than the width of the base portion of the profiles.

In a preferred embodiment the wall system according to the invention has substantially all profiles arranged and fastened to parts of the building different from the building wall, so that no elements connected to said profiles except the insulation panels them selves span from the first major surfaces of the insulation panels to the second major surfaces of the insulation panels. Preferably, also the base portions of the profiles are placed parallel to a minor surface of the insulation panels and between the first major surface of the insulation panels and the slit in a minor surface of the insulation panels.

This means that the two wall parts are not directly connected by mechanical means. If there is an air gap between the two wall parts they will not be connected at all. If there is no air gap they will only be connected through the heat insulating material, possibly with some adhesive between the second major surface of the insulation panel and the building wall.

Preferably, C- or U-profiles are applied for the framework holding the insulation panels. These profiles will comprise one base portion and two flange portions extending from the base portion. One of these flange portions are arranged to penetrate into the slit in the insulation panels in order to hold the insulation panel in position. Other means for achieving this purpose could also be applied, e.g. punched out pieces from the base portion or screws or clips, and then an L-profile could be sufficient. The other flange portion is arranged to be flush with a major surface of the insulation panel. This major surface of the insulation will often be the outer surface opposite the first part of the wall. These types of profiles have the advantage of fixing the insulation panels better into the correct position. Furthermore, a flange placed opposite the other first part of the wall and flush with the outer major surface of the insulation panel, may be used for attaching a cover layer to this side of the wall. This cover layer could be gypsum boards, wood panels, fibre boards or any other material suitable for cladding of inner walls.

In a further preferred embodiment the wall system according to the invention has two substantially vertical profiles holding the insulation panel, and a first profile has a flange portion extending into the slit in the insulation panel and a second profile has a flange portion pointing away from said insulation panel. The flange portion pointing away from the insulation panel is arranged for holding a neighbouring insulation panel. Furthermore, the second profile may be provided with fixation means for holding the said first mentioned insulation panel in place. These fixation means may e.g. be arranged after placement of first mentioned insulation panel but before placing the second neighbouring insulation panel in position.

The framework of profiles, which usually form one or more frames in which the insulation panels are installed, will often be attached to the floor and the ceiling with one horizontal profile attached to the floor and one attached to the ceiling. Vertical profiles are placed between the horizontal profiles. In building or parts of buildings where the distance between floor and ceiling is particularly large one or more vertical supporting profile could be added in a position between the floor and the ceiling.

The framework of profiles could also be attached to the walls perpendicular to and adjoining the new inventive wall system. This would be especially relevant when the new wall system is applied for an external wall being part of the building façade.

In a further preferred embodiment of the invention the majority of the insulation panels, preferably of mineral wool, comprise at least two different layers having different densities. Often, this will be made as so-called dual density boards, meaning that the panels comprise layers, extending parallel to the major surfaces, of different densities. Usually, this will be in the form of one relatively thin layer (up to 25% of the total thickness of the insulation panel) with a high density, e.g. higher than 60 kg/m³. The remaining part of the insulation will be of a lower density, e.g. below 45 kg/m³. One advantage of such an insulation panel is that a high degree of mechanical stability may be achieved from the high density layer without getting a very heavy product.

In a further embodiment of the invention a high density layer of the insulation could substitute a cover layer. If the surface of the insulation facing the occupied room is sufficiently hard and stable, it may not always be necessary with a separate cladding layer. In these cases the high density layer of the insulation could be covered by a fleece and/or paint in order to improve the aesthetic appearance of the surface and/or to improve the wear resistance of the surface. If the mineral wool is covered by a fleece or a paint layer having an open or porous surface it will have the advantageous effect of higher acoustic absorption than a traditional covering layer of e.g. gypsum boards. In such an embodiment the layer in the insulation with the highest density will be placed opposite the building wall of the system.