Background Buildings have to become more energy-efficient and healthier. A prerequisite to make them more energy-efficient is improved insulation. Improved insulation reveals itself if hardly any hot air flows from the inside to the outside when heating the constructed space. In those locations where large amounts of hot air flow away, not only is energy lost, but areas which become moist due to local condensation are formed. Locations which become breeding grounds for moulds and thus form a health hazard for the occupants. Preventing undesirable air flows from the inside to the outside is referred to as 'airtight construction'.

The locations via which most air flows away are usually the connections between the various building sections. In modern construction, the building sections are becoming increasingly larger, entire roofs, bathrooms and facades are fitted to the front of and the inside of shells and dwellings to be renovated. In order to be able to fit and position one building section next to another building section, adjusting space is always required which results in a seam or gap after construction. A seam or gap generally leads to air flows which, in turn, have to be prevented. The larger the building sections, the greater and more uneven the seams and gaps.

The common solutions for preventing air flows consist of blocking the undesirable airflow using sealant, tape, rubber strips, PU foam and the like. These are used to seal said seams and gaps. These solutions have significant drawbacks. The main drawback is the fact that these solutions are effective with small seams and gaps, but not in the case of large irregular and voluminous seams and gaps.

A second drawback is the fact that these solutions may possibly provide airtightness, but that complete filling of gaps, which is required to also bring about good thermal resistance, is not achieved. With many of the products used, gaps are filled to a large degree, but not completely. A possible example is the use of PU foam to seal gaps which arc difficult to reach. In practice, the PU foam is found not to reach everywhere, resulting in a gap which is not entirely sealed.

The fact that PU foam does not completely fill seams and gaps is partly due to the uncontrolled expansion of the foam which follows the path of least resistance.

Incomplete filling again results in an airflow being created, which in turn means that thermal resistance is insufficient.

A third drawback is the fact that the solutions do not follow the movements of the building, or only for a relatively short time. In practice, the modern - relatively - rigid / static building sections are constantly moving to a limited degree. This means that the dimensions of the accompanying connections (the seams and gaps) are not constant. In view of the aforementioned product properties of the present 'solutions', hardening or becoming detached, their effect is of only limited duration. A fourth drawback is the fact that once the airtightness has been compromised, this cannot be automatically restored. The air pressure may peak to such a degree that, for example due to a storm or the slamming of doors, the airtightening means fail. In that case, for example, the tape becomes detached or the PU foam drops out or the sealant / rubber strip becomes detached or is mispositioned due to the air pressure, etc. Once the air pressure has returned to normal, the airtightening means cannot resume its original function, in other words, it cannot restore itself, which is a major drawback. This drawback is aggravated if the seal is excessively airtight and the pressure on the bond consequently becomes too great at peak load. A fifth drawback, and the most significant problem for the implementation, is the fact that the present construction methods and builders are not accustomed to working accurately with sealant, tapes and PU foam. The implementation (and thus the effect) is therefore rarely satisfactory, which only adds to the frustration of the builders. A sixth drawback is the fact that said seams and gaps are not only the weakest link regarding the air resistance and the thermal resistance, but also offer least resistance with regard to fire resistance and noise resistance. The modern building sections which are assembled in a factory satisfy the highest demands with regard to heat, moisture, fire and noise resistance. The seams then have to be sealed on the building site and will have to be of equal or better quality in order to ensure the performance of the whole, the assembled building. EP 2 913 470 Al in the name of "Korea Institute Of Construction Technology" relates to a filler material and a filling method for filling an opening between structural building parts. The expansion material is compressed when the inside of a cover material is vacuumized. To this end, a nozzle is provided at one end of the cover material. This results in a number of drawbacks. The expansion material is compressed very unevenly, since evacuation or vacuumization takes place at a point, the nozzle. The uneven compression of the expansion material results in the material becoming damaged and losing its resilience. Furthermore, the length of the combination of expansion material and cover material which can be produced is limited. Summary of the invention

The parties involved therefore desire to have a solution which suits the construction process and results in a long-lasting sealing of the connections between building sections. In the construction of new buildings, connections are therefore sealed by fitting a rubber- like strip on the connecting sides of the building sections (the efficiency of which is incidentally also reduced over time). Not all connections are suitable for this treatment, for example because the space to be filled is too large or irregular. In order to solve the problem, the following application has been devised and worked out, effectively the invention, expansion wool. The expansion wool is characterized by an accurate definition of the size and composition of an amount of mineral wool (glass wool or rock wool), to compress the latter and to keep it compressed until the moment of application, by generating partial vacuum or by using vacuumizing techniques. Subsequently, the compressed mineral wool may be applied in the seam to be sealed, after which the partial vacuum is removed. This fitting technique has the significant advantage that the connection, which is the result of the construction process and is precisely defined, will ALWAYS be completely filled. By applying an excess of mineral wool (due to the production technique, the mineral wool is still compressed during fitting) and making use of the lasting elasticity of the wool, the connection is readily able permanently to follow movements of the building and will thus last for years. In order to maintain the compressed state by partial vacuum up to and including the moment of application, the mineral wool has to be packed in an airtight manner.

The compressed wool (expansion wool) is fitted in the connection together with the airtight packaging, following which the partial vacuum is removed by piercing the airtight packaging at specific locations. This airtight packaging remains in the connection and thus increases the air resistance of the connection. Due to the excess of mineral wool, the thickness of the wool is a multiple of the width of the seam or gap, the airtight packaging will be pressed against the sides of the seam after piercing. If necessary, the air resistance of the seal may be increased by providing the packaging of the mineral wool with connecting strips and flaps, should the specific construction elements require this for the desired degree of airtightness.

The elasticity of the wool causes an airflow, going from the inside to the outside, to have to flow along the packaging pressed against the connection. Therefore, this connection is not completely airtight (which is effectively undesirable), but the resistance is such that it amply meets the requirements on airtightness which modern buildings have to meet. It is noteworthy that expansion wool is the only solution which is self-repairing, in fact it forms a kind of pressure relief valve. In case of a temporarily very high air pressure, such as with a storm, some air will flow along the packaging and the connecting seams. When the air pressure subsequently drops to normal values again, the desired optimum seal is achieved again.

The expansion wool can be made to measure and can be modified, as a result of which this is the only solution which is able to combine several functions, such as the aforementioned airtighting and the desired thermal resistance. Consideration must also be given to fire resistance, dampproofness, dampness control and noise resistance. Expansion wool and the airtight packaging are easy to separate from the construction waste in case of demolition of the building or renovation and are completely recyclable, as a result of which the environmental load ofthe building decreases. The actual connection between building sections to the degree desired by the client can thus be defined and produced beforehand and is effected in a controlled manner after the building sections have been fitted.

Wool, such as mineral wool (rock wool) or glass wool, is composed of fibres which, depending on the production process, are built up in layers in accordance with a pattern. The fibres themselves are not or hardly elastic, with glass wool being more elastic than rock wool. It is the arrangement of the fibres which makes the entirety of the wool more or less elastic. This becomes clear when the wool is being compressed. When the wool is being compacted, most fibres break and the wool does not spring back. This is also the case if the wool is not compressed homogeneously, but unevenly, for example by sucking the air out using a hose connected to an airtight bag. Research suggests that the optimum result is achieved by fitting the entirety of the wool to be compressed in a partial vacuum or vacuum chamber, to apply a partial vacuum/vacuum and to seal in this state, and then to remove the partial vacuum/vacuum again. As mentioned before, the arrangement of the fibres is also important with regard to the elasticity. The more the fibres are oriented horizontally, the higher the elasticity after vacuumization. In addition, more air is removed from the wool in this way.

It is possible to obtain a continuous strip of wool compressed by vacuumizing technique by 'deep-drawing', a technique in which airtight sealing or sleeve of plastic film is pre-formed in a mould. The wool is placed on a first deep-drawn film in the deep- drawing mould, is covered with a second plastic film, placed in a partial vacuum or vacuum chamber and is sealed under a partial vacuum/vacuum. Deep-drawing a part of the sleeve may ensure a preferred direction ofthe expansion of the wool. This may result from the sleeve being less elastic than the wool. The direction of the fibres of the wool also determines the preferred direction during expansion of the sealed wool. The wool is therefore cut in such a manner the expansion wool expands in the desired direction. The combination of the wool in the preformed sealing may be produced in desired predetermined lengths. It is also possible to place the wool in long strips as a tubular film and to seal it in a vacuum chamber. These long strips may have lengths of 3 to 6 m. Vacuumization in this manner requires a pre-treatment of placement in moulds.

Incidentally, production is also possible by means of a continuous process, as a result of which a film strip is produced which contains pieces of enclosed compressed wool. By cutting the strip into pieces, cutting the enclosed pieces of compressed wool apart at the locations where the bottom and top film are welded together and gluing these pieces together in a staggered manner, a continuous strip is produced. By placing them in a staggered manner, the parts fit exactly onto one another after expansion and a uninterrupted continuous long sealing is obtained which can be separated into strip parts at fixed locations while maintaining the compressed state.

An advantage of the method according to the invention is the fact that by evenly compressing the wool, the structure of the wool is maintained. As the method ensures minimal breakage of fibres, the elasticity is retained. Upon expansion, the form thus tends to assume its original shape, since the fibres are still intact. In this way, mineral wool may expand at an expansion factor of at least 2-3 (in volume). Although this document mainly discusses mineral wool (in particular rock wool), this invention also applies to glass wool. With glass wool, a volume expansion factor of at most 9 may be achieved. The reduction in volume by compression results in a lowering of the transportation costs and consumption while maintaining insulating value. Polyester wool is also possible, but the elasticity of polyester wool decreases quickly over time as a result of deformation of the fibres. In other words, polyester wool is not elastic for a prolonged period of time and highly flammable. When compressed for a long period of time, polyester wool assumes the shape of the sleeve and the resilience will be minimal. A further advantage of the method according to the invention is the fact that the direction of the expansion can partly be guided by the original shape/structure of the preformed sealing.

In an embodiment, the method furthermore comprises:

- producing a strip of pieces of mineral wool;

- cutting the strip into pieces of compressed mineral wool;

- gluing the pieces of compressed mineral wool together, so that these can be folded and packaged; splitting the glued parts for

The invention furthermore relates to a method for providing a compressed element of mineral wool or glass wool, for sealing a seam or gap, comprising the following steps:

- providing at least one element of mineral wool or glass wool, made in a shape which is configured for sealing the seam or gap;

- introducing the element in a vacuum chamber;

- removing the air from the vacuum chamber;

- sealing the element in a sleeve in an airtight manner;

- allowing air to enter the vacuum chamber so that the element is compressed.

In an embodiment, the method for providing a compressed element furthermore comprises:

- preforming a piece of film in a mould which is shaped in the form of the element;

- placing the element in the piece of film;

and wherein introducing the element in a vacuum chamber comprises introducing the piece of film into the vacuum chamber together with the element. In an embodiment, providing at least one element of mineral wool or glass wool comprises:

- adding one or more layers of an intimising or fire-resistant product to the element.

More generally, this embodiment comprises the method of adding an intimising, that is to say a fire-resistant product. This makes it possible to provide an element which is both elastic and has fire-resistant action. The fire-resistant product will render the element slightly stiffer. The fire-resistant product expands and/or foams when heated. In an embodiment, the element comprises glass wool and fire-resistant product. Due to the glass wool, the element expands after fitting. During a fire, the glass wool may shrink, but the fire-resistant material will, on the contrary, expand or foam on account of the heat. In this way, the seam, gap or opening remains closed to air, which tempers the fire. Once the maximum temperature has been reached, the fire-resistant material has taken up all of the space. This ensures that the element will continue to seal the seam, gap or opening and cannot drop out.

The modification of addition of one or more layers of intimising or fire-resistant product is advantageous. You cannot impregnate the wool and make it become elastic.

Impregnation will make the wool stiffer. By working with 2 layers, the glass wool fulfils the role of expansion and the fire-resistant material will be expanded in case of fire on account of the heat. Sealing is therefore effected with certainty where the sleeve will quickly melt. The fire-resistant material foams where the glass wool melts away at 600 degrees Celsius. This has 2 major advantages, the opening remains closed to air which tempers the fire. Once a high temperature is reached, the fire-resistant material will have taken over the entire space. This is important because the material has to remain in the opening until it has fully foamed. This advantage is not known from the prior art and known expansion elements drop out of the gap or crevice to be sealed. The invention furthermore relates to a method for sealing a seam, gap or cavity, wherein the method comprises:

- providing a compressed element of mineral wool or glass wool as mentioned above;

- placing the compressed element in the seam, gap or cavity;

- piercing the sleeve or the film, as a result of which the element expands and seals the seam, gap or cavity.

The invention furthermore relates to a use of an aforementioned compressed element around cylindrical objects, such as pipes, lead-throughs, etc. The elongate design (strip) is fitted around the object. In an embodiment, the compressed element is fitted rotating anticlockwise with respect to the cylindrical object. By subsequently rotating clockwise, the partial vacuum in the compressed element is removed. This is possible, for example, by arranging pins on the outside of the compressed element. Description of figures.

The invention will be explained in more detail by means of drawings of (non- limiting) exemplary embodiments, in which: Fig. 1 shows a diagrammatic representation of construction elements;

Fig. 2 shows a diagrammatic representation of expansion wool between floor elements; Fig. 3 shows a diagrammatic cross section of the action of expansion wool;

Fig. 4 shows a diagrammatic representation of facade elements (for example with renovations);

Fig. 5 shows a diagrammatic representation of a connection in case of facade renovation; Fig. 6 shows a diagrammatic representation of a lead-through for pipes through the roof; Fig. 7 shows an embodiment of expansion wool around the lead-through;

Fig. 8 shows a diagrammatic representation of a casing in a facade;

Fig. 9 shows a diagrammatic representation of a cross section of the connection cavity wall/casing;

Fig. 10A-D show a diagrammatic representation of the vacuumization process; and Fig. 11A-B show a strip.

Of course, in practice there are many more seams and gaps present in the construction industry, these can all be filled by means of the present invention. The above examples are an attempt to make the possibilities clear and form a limited selection of all seams and gaps which are present in the construction industry.

Fig. 1 shows a modular construction (1) during the so-called shell construction phase. Concrete floor slabs (2) are placed on a foundation by means of cranes on the construction site. The concrete floor slabs (2) have been produced in a factory and provided with hollow spaces. In this figure, reference numeral (3) denotes the wall sections and (4) the facade sections. Fig. 2 shows that, in order to prevent transmission of sound, the ends of the floor slabs of the one dwelling are not allowed to touch those of the adjacent dwelling. In this case, the hollow ducts have to be sealed sufficiently airtight, as does the seam between the wall sections (3) at the end of the floor slabs. Due to the floor slabs having been laid using a crane, the space between their ends is uneven and jagged. This seam is to be filled over its entire height and width with the expansion wool in the compressed state (5). When the partial vacuum is removed, the wool expands and the packaging seals the ducts, the entire seam is filled and the air resistance is sufficient to prevent air from being able to move via the ducts, via the wall connection or via the foundation. This is shown in more detail in Fig. 3, which illustrates the fact that the expansion wool (5) seals off the ducts in the floor slabs (2) as well as the seam between the wall sections (4) in a satisfactory manner after the partial vacuum is removed.

Fig. 4 diagrammatically shows a modular construction during the renovation stage. In case of renovation, the dwellings (6) are provided with a new roof and facade OVER the prepared existing dwelling. Examples of ageing modular construction dwellings are blocks of flats from the fifties, house buildings from the sixties, but also the concrete office buildings with mathematical layout. In preparation of the renovation, parts of the old facade and roof are removed. The raw 'shell' remains and a prefabricated facade (7) or roof element is attached. A cross section of the connection is worked out in Fig. 5. The seam between the raw shell (8) and the new construction element (7) is very uneven in thickness and surface.

By providing the new building section to be fitted with a recess comprising the expansion wool (5), the seams are completely filled in a reliable manner beforehand and the air resistance can be achieved along the entire width of the seam. If desired, the airtight packaging may additionally adjoin damp-inhibiting layers, by means of which the air resistance is further ensured. In addition to this form of applied facade elements, completely prefabricated construction is also increasing, in which facade elements are also manipulated as casings. In this case, the expansion wool may also be used with great success to fill the spaces/connections between the various facade elements in an airtight manner in accordance with the requirements.

Figs. 6 and 7 show another particular application of the expansion wool which may be used in lead-throughs (9) in roofs (10). In particular in cases where hot gases pass through the lead-throughs, such as with chimneys and other flue gas lead-throughs, the sealing and fire resistance around the lead-throughs is very important. It is so important that the sealing is standardized and the lead-throughs have to guarantee to offer sufficient resistance to fire and air. Many lead-throughs which have been retrofitted into walls, floors and roofs suffer from the problem that the space between the lead-through and the hole in this wall, floor or roof structure is not completely filled. This is solved by draping the expansion wool (5) around the lead-through (9) and modifying the expansion wool. The modification may be, for example, rendering the wool more fire-resistant, such as providing the wool with additional graphite-containing means which expand and seal more at high temperatures, but other solutions are also possible. For this purpose, the mineral wool to be used is cut in such a manner that the wool is radially homogenous upon expansion, and subsequently compressed using a partial vacuum.

Another application is captured in Figs. 8 and 9, the expansion wool for casings (1 1) and lower fronts, in which the casing or the lower front has to be placed in a recess in the facade. The facade (12) may be both an existing facade which has been provided with a recess and a new facade which has been provided with a recess. In order to be able to place the casing or the lower front in the recess, the recess has to be larger than the casing or the lower front. It may also be the case that the shape of the recess may deviate from the casing or the lower front, as a result of which the size of the recess deviates even more. After the casing or the lower front has been placed, the remaining space, in the form of a seam or gap, has to be closed off.

The sealing has to be sufficiently heat-resistant and air-resistant and moisture- resistant and fire-resistant. By providing the casing or the lower front with a groove on all sides and providing the expansion wool therein in such a manner that the expansion wool does not protrude beyond the groove in the compressed state, the casing or the lower front can be placed as intended and the sealing can readily be achieved by removing the partial vacuum after fitting. If desired, additional resistance may be achieved by allowing the packaging of the expansion wool to adjoin damp-inhibiting layers or other features which are present in the wall.

Figure 10A-D diagrammatically shows the vacuumization process according to an embodiment. Fig. l OA shows a preformed sleeve 20 in a vacuum chamber 30. In Fig. 10B, the sleeve 20 is deep-drawn on a first side 20a in a preferred direction Z' : along an axis a, by reducing the pressure in the vacuum chamber 30. The sleeve 20 is held in a mould (not shown) on a second side 20b. In Fig. IOC, an element 22 of mineral wool or glass wool is placed in the sleeve 20 and the sleeve 20 is sealed in an airtight manner. The element 22 is composed of layers. The layers extend at right angles to the preferred direction a in which the first side 20a has been deep-drawn. The layers follow one another in the preferred direction a in which the first side 20a has been deep-drawn. The fibre orientation of the wool may differ for each layer, preferably the fibre orientation in successive layers is at right angles to each other. In Fig. l OD, the pressure in the vacuum chamber 30 is returned to atmospheric pressure. As a result thereof, the sleeve 20 with the element 22 therein is compressed. This vacuumization process may also be carried out without deep-drawing a part of the sleeve 20.

Figure 11 A shows a part of a film strip LI with elements of compressed wool 40a, 41a, 42a, 43a. Pieces of film with packaged compressed wool 40, 41 , 42, 43 are connected to each other and form a strip LI which may be extremely long. It is possible to cut the pieces of film 40, 41, 42, 43 loose from one another over the boundary lines 50, 51 , 52, also sealing seams.

Figure 1 IB shows a part of film strip L2 with pieces of film with packaged compressed wool 40, 41, 42, 43. The strip L2 has been produced by cutting loose the strip LI shown in Figure 1 1A along the boundary lines 50, 51, 52, and then gluing or welding them together again, while every second piece of film 41, 43 is rotated through 180 degrees over an axis defined by the longitudinal direction of the strip L2. The result is the fact that every piece of film 40, 41 , 42, 43 is oriented upside down with respect to the adjacent pieces of film 40, 41, 42, 43. The cut boundary lines 50, 51, 52 are in this case pushed slightly over the adjacent pieces of film 41, 42, 43. The elements of compressed wool 40a, 41a, 42a, 43a are in this case pushed against each other, so that they form a very long continuous sealing. The invention will be described further by the following clauses:

1. Producing durable connections between parts of buildings in a controlled manner, which connections meet the imposed requirements on airtightness and thermal resistance by temporarily compressing mineral wool of large dimensions up to and including the moment of fitting by means of a partial vacuum or by vacuumization, so that the mineral wool can be fitted without disturbing the construction process, following which the compressed mineral wool expands in the desired direction by removing the partial vacuum, wherein the connection is entirely filled along the entire length, the airtight packaging brings about the resistance against air flow and thus ultimately achieves the desired airtight result.

2. Producing, in a controlled manner, a fire-resistant connection which has been achieved by modification between building sections which meet the imposed

requirements of fire resistance by temporarily compressing modified mineral wool of large dimensions up to and including the moment of fitting by means of a partial vacuum or by vacuumization, so that the modified mineral wool can be fitted without disturbing the construction process, following which the compressed modified mineral wool expands in the desired direction by removing the partial vacuum, wherein the connection is entirely filled along the full length, the airtight packaging brings about the resistance against air flow and thus ultimately achieves the desired airtight result, wherein the desired fire resistance is achieved by the modification of the mineral wool.

3. Producing a form of the mineral wool which is cut specially in addition to Claim 2 for round through-pipes, wherein the expansion in the radial direction is homogeneous (see Figure 7).

4. Producing a further increased resistance to air flow in addition to Claim 1 or Claim 2 by providing the airtight packaging of the compressed mineral wool with additional flaps and/or strips.

5. The ability to produce a desired resistance to air flow in addition to Claim 1 or Claim 2 at locations specified for the purpose, wherein flow is only possible in case of superatmospheric pressure and the connection regains the desired resistance to air flow upon return to normal air pressure.

6. Prefabricating an arbitrary desired detailed form in mineral wool, optionally modified, and compressing the latter by a partial vacuum or by vacuumization, so that it can be fitted in a connection in a controlled manner and expands in the correct direction and size after the partial vacuum is removed, by way of non-limiting example, roof lead- throughs (see Figure 7), stove pipes, etc.