Rear-ventilated building facade as well as process for manufacturing same

Abstract

The present invention pertains to a rear-ventilated building facade with a load-bearing external wall, with an insulation layer formed from insulation panels and with a facade cladding, wherein the facade cladding is installed by means of a load-bearing structure, forming a rear ventilation gap, at a spaced location from the insulation layer, and wherein the rear ventilation gap is interrupted in the vertical direction by at least one fire barrier, which is configured as a mineral wool panel. It is characterized in that the at least one fire barrier extends over the entire width of the rear ventilation gap, and that the at least one fire barrier has at least one opening extending in the vertical direction in the area of the rear ventilation gap. The present invention further provides a process for manufacturing a rear-ventilated building facade. It is thus possible to perfect a rear-ventilated building facade of this class such that a lastingly reliable fire protection can be achieved with a cost-effective configuration.

Claims

1. Rear-ventilated building facade (1) comprising: a load-bearing external wall (2), an insulation layer (3) formed from insulation panels (31) and fastened to the external wall (2), a facade cladding (4) installed by means of a load-bearing structure forming a rear ventilation gap (5) at a spaced location from the insulation layer (3), and at least one fire barrier (6, 6′) configured as a mineral wool panel and interrupting the rear ventilation gap (5) in the vertical direction, wherein the fire barrier (6, 6′) extends over the entire depth of the rear ventilation gap (5), characterized in that the at least one fire barrier (6, 6′) has at least one opening (62,63) extending in the vertical direction in the area of the rear ventilation gap (5) wherein a sum of areas of the at least one opening (62, 63) per linear meter equals to or is less than 100 cm.sup.2.

2. Building facade in accordance with claim 1, characterized in that the fire barrier (6) has uniformly distributed openings in the form of holes (62).

3. Building facade in accordance with claim 1, characterized in that the fire barrier (6′) has openings in the form of regular recesses (63) arranged at the edge.

4. Building facade in accordance with claim 1, characterized in that a sum of areas of the openings per linear meter equals to or is less than 80 cm.sup.2; and/or the sum of areas of the openings per linear meter is not less than 60 cm.sup.2.

5. Building facade in accordance with claim 1, characterized in that the fire barrier (6) has a thickness between about 2 cm and about 10 cm.

6. Building facade in accordance with claim 1, characterized in that the fire barrier (6, 6′) has an apparent density between about 60 kg/m.sup.3 and about 300 kg/m.sup.3.

7. Building facade in accordance with claim 1, characterized in that the fire barrier (6, 6′) extends from the facade cladding (4) into the insulation layer (3), wherein the fire barrier (6, 6′) extends from the facade cladding (4) through the insulation layer (3) to the external wall (2).

8. Building facade in accordance with claim 1, characterized in that the mineral wool of the fire barrier (6, 6′) has a laminar fiber structure.

9. Building facade in accordance with claim 1, characterized in that the fire barrier (6, 6′) has an intumescent coating.

10. Building facade in accordance with claim 1, characterized in that the insulation panels (31) of the insulation layer (3) are formed from mineral wool.

11. Process for manufacturing a rear-ventilated building facade in accordance with claim 1, characterized by the steps: fastening of a load-bearing structure to a load-bearing external wall (2), fastening of an insulation layer (3) formed from insulation panels (31) to the external wall (2), formation of at least one slot (32) in the insulation layer (3), insertion of at least one fire barrier (6, 6′) configured as a mineral wool panel into the slot (32), and installation of a facade cladding (4) on the load-bearing structure such that the facade cladding (4) is arranged at a spaced location from the insulation layer (3), forming a rear ventilation gap (5), wherein the at least one fire barrier (6, 6′) extends over the entire depth of the rear ventilation gap (5), and wherein the at least one fire barrier (6, 6′) has at least one opening, which extends in the vertical direction and which comes to lie in the area of the rear ventilation gap (5).

12. Process in accordance with claim 11, characterized in that the at least one slot (32) is formed in the insulation layer (3) by a) cutting into the flatly laid insulation layer (3), wherein the insulation material is removed from the area of the slot (32); or b) installing the insulation panels (31) of the insulation layer (3) at spaced locations from one another such that the at least one slot (32) is obtained between vertically adjacent insulation panels (31).

13. Process in accordance with claim 11, characterized in that the at least one fire barrier (6, 6′) is inserted into the associated slot (32) to a predetermined extent, wherein the at least one fire barrier (6, 6′) is inserted through the entire insulation layer (3) up to the external wall (2).

14. Process in accordance with claim 11, characterized in that the fire barrier (6, 6′) is pressed into the slot (32) or clamped between two vertically adjacent facade insulation panels (31).

15. Process in accordance with claim 11, characterized in that fire barriers (6, 6′) are arranged in every floor of the building.

16. Process in accordance with claim 11 characterized in that at least the facade insulation panels (31) of a layer of facade insulation panels (31) directly above the fire barriers (6, 6′) are vertically slidably secured to the external wall (2).

17. The building facade according to claim 4, wherein the sum of areas of the openings per linear meter is equal to or is less than 70 cm.sup.2.

18. The building facade according to claim 5, wherein the fire barrier (6) has a thickness between about 3 cm and about 5 cm.

19. The building facade according to claim 6, wherein the fire barrier (6, 6′) has an apparent density between about 80 kg/m.sup.3 and about 200 kg/m.sup.3.

20. The building facade according to claim 19, wherein the fire barrier (6, 6′) has an apparent density between about 100 kg/m.sup.3 and about 150 kg/m.sup.3.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will be explained in more detail below on the basis of the drawing figures. In the drawings,

(2) FIG. 1 shows a schematic lateral view of a rear-ventilated building facade according to a first embodiment of the present invention;

(3) FIG. 2 shows a perspective view of a fire barrier according to the first embodiment;

(4) FIG. 3 shows a perspective view of a fire barrier according to a second embodiment; and

(5) FIG. 4 shows a schematic lateral view of a rear-ventilated building facade according to the present invention according to another embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

(6) According to the view in FIG. 1, a building facade 1 has a load-bearing external wall 2. An insulation layer 3 is fastened by means of adhesive and/or dowel on the outer side of the external wall 2 in a manner that is conventional per se. Further, the building facade 1 has a load-bearing structure made of metal, which is not shown for the sake of simplifying the view and which is fixed on the external wall 2. The load-bearing structure holds a facade cladding 4, forming a rear ventilation gap 5 between the insulation layer 3 and the facade cladding 4 at the external wall 2.

(7) The insulation layer 3 is constructed from a plurality of insulation panels 31, which possess good thermal insulation properties. For example, facade insulation panels with a thermal conductivity WLG035 are suitable for this. These have a very low thermal conductivity and therefore great thermal insulation and offer good fire protection. An incombustible insulation panel, Euro Class A1, with a melting point of >1,000° C. and an apparent density of about 25 kg/m3 is used in the exemplary embodiment.

(8) Further, the building facade 1 has a plurality of fire barriers 6, which are configured as mineral wool panels and which are used as a horizontal fire barrier in the rear ventilation gap and one of which is shown in more detail in FIG. 2. These fire barriers 6 are arranged in every other floor of the building as a horizontal fire barrier in the rear ventilation gap 5 in accordance with the technical building codes of the Deutsches Institut für Bautechnik. However, tests have shown that the fire barriers 6 are preferably arranged in every floor of the building.

(9) An incombustible (Euro Class A1) mineral wool insulation panel with laminar fiber orientation, with a melting point of >1,000° C. and an apparent density of about 140 kg/m3 is used as a fire barrier 6 in this exemplary embodiment. The thickness of the panel is about 3 cm.

(10) The fire barrier 6 has a blocking body 61, which extends from the external wall 2 to the facade cladding 4 and thus interrupts the insulation layer 3. The fire barrier 6 is received clampingly in a slot 32 of the insulation layer 3 in the exemplary embodiment shown. The end of the blocking body 61 facing the external wall 2 is bonded to this wall and is thus fixed thereto. With the outside end, the blocking body 61 of the fire barrier 6 is in contact with the facade cladding 4 such that no gap is essentially formed there. The blocking body 61 has a laminar fiber structure, as a result of which the fibers are essentially at right angles to the external wall 2.

(11) In the area of the rear ventilation gap 5, the fire barrier 6 has a plurality of uniformly distributed openings in the form of holes 62, which allow the passage of air in the rear ventilation gap 5. The holes 62 extend for this through the entire thickness of the blocking body 61 and thus connect the spaces above and below same. The size of all openings present in the fire barrier 6 due to the holes 62 is limited to 100 cm2 per linear meter. More preferably, the size of the openings is limited to 80 cm2, in particular 70 cm2 per linear meter. On the other hand, the size of all openings should preferably be greater than 60 cm2 per linear meter. In a test, excellent results are achieved with the size of all openings of 60 cm2 per linear/running meter.

(12) The facade cladding 4 has a plurality of cover panels 41, which have a flexurally rigid configuration and are fixed one by one on the load-bearing structure. Fiber cement panels were used as cover panels 41 in the practical test.

(13) This configuration was subjected to a practical test, which was successful, in the course of the present invention. The fire barriers 6 prevented the spread of fire or the jumping over of the fire after the end of the test over the required time period of 30 minutes. It was seen, in particular, that the energy sent through the holes 62 did not suffice to cause the fire to spread.

(14) FIG. 3 shows another embodiment of a fire barrier, which is designated by the reference number 6′. This differs from the fire barrier according to the first embodiment in the configuration of the blocking body 61′ and of the openings.

(15) As is seen in the view shown in FIG. 3, the openings are configured in the form of regular recesses 63 located at the edge. This leads to a crenellated structure at the lateral edge of the fire barrier 6′, which edge faces the facade cladding 4.

(16) FIG. 4 shows a schematic lateral view of another embodiment of the rear-ventilated building facade 1.

(17) This differs from the above-described embodiment, on the one hand, in that the fire barrier 6′ just explained is used with a crenellated edge side. Moreover, the fire barrier 6′ does not pass completely through the insulation layer 3 but extends into same to a predetermined extent only, here over about ⅓ of the overall thickness of the insulation layer 3. The slot 32 was formed for this in advance with the desired depth in the insulation layer 3, and the fire barrier 6′ was finally inserted into this slot under pressure. It is thus held clampingly in the insulation layer 3.

(18) The slot 32 was not formed at right angles to the large surface of the insulation layer 3 but sloped by a few degrees relative thereto. As a result, the fire barrier 6′ is positioned obliquely in relation to the insulation layer 3 such that it hangs somewhat outwardly away from the insulation layer 3 and thus guides water away from the insulation layer 3 if necessary.

(19) A process for manufacturing the rear-ventilated building facade 1 will be explained below.

(20) The load-bearing structure is first fastened here to the bearing external wall 2. This is carried out in the usual manner by means of screws and dowels. The insulation layer 3 is then built up on the external wall 2, for which the insulation panels 31 are bonded on and/or fixed by means of dowels one after another to form a closed insulation surface. The elements of the load-bearing structure are correspondingly recessed at the locations at which the insulation layer 3 is interrupted by elements of the load-bearing structure.

(21) The slots 32 are finally inserted at the predetermined locations into the insulation layer 3 by means of a knife or the like. Two incisions are concretely made now in the insulation layer 3 at spaced locations from one another and the insulation material located between them is subsequently removed.

(22) The fire barriers 6 and 6′ can then be inserted into the slots 32, because this is carried out under pressure and clamping of the fire barriers 6 and 6′ in the insulation layer 3 is thus achieved.

(23) The depth of the slots 32 prepared can be adapted to the particular application. It may be limited, as is shown in FIG. 4. It may, however, also pass completely through the insulation layer 3, as this is shown in FIG. 1. Also, the slot 32 may be formed between two vertically adjacent facade insulation panels 31. In such case the fire barriers 6 are arranged, preferably clamped, between the two vertically adjacent facade insulation panels 31. At least the facade insulation panels 31 of a layer of facade insulation panels 31 directly above the fire barriers 6 and 6′ may be vertically slidably secured to the external wall 2. For installing the fire barriers 6 and 6′ the upper layer of facade insulation panels 31 are shifted upwards to form the slot 32, then the fire barriers 6 and 6′ are inserted into the slot and finally the facade insulation panels 31 are moved down again, especially so that the fire barriers 6 are clamped between the vertically adjacent facade insulation panels 31.

(24) It is essential that the fire barriers 6 and 6′ extend over the entire depth of the rear ventilation gap 5. Further, the fire barriers 6 and 6′ have, in the area of the rear ventilation gap 5, uniformly distributed holes 62 or regular recesses 63 located at the edge, as they can be seen in FIGS. 2 and 3.

(25) Finally, the facade cladding 4 is installed on the load-bearing structure such that it is located at a spaced location from the insulation layer 3, forming the rear ventilation gap 5. The fire barriers 6 and 6′ are now in contact with the facade cladding.

(26) The rear-ventilated building facade is thus finished.

(27) The rear-ventilated building facade 1 according to the present invention further allows the additional configuration principles explained below.

(28) Thus, it is not necessary for the openings to be present in a uniformly distributed manner at the fire barrier 6. They may also be formed irregularly or mixed in the form of holes 62 and in the form of recesses 63 located at the edge.

(29) The recesses 63 do not have to have the rectangular shape shown in FIG. 3; they may also have a triangular, semicircular or another suitable geometry.

(30) It is equally unnecessary for the holes 62 to have a round shape; they may also have a different cross-sectional shape and be configured as elongated holes.

(31) In the type of configuration explained, the fire barrier 6 has a thickness of about 3 cm, but this is not necessary; depending on the application, it may also have a thinner or thicker configuration. Material thicknesses between 2 cm and 10 cm have proved to be especially suitable in this connection.

(32) A mineral wool panel suitable for the application, which is different from the one explained, may also be used for the fire barrier 6 insofar as this possesses suitable fire protection properties.

(33) Thus, the apparent density of the fire barrier 6 may also have a value different from the value of 140 kg/m3 as explained. A mineral wool panel with apparent densities between 60 kg/m3 and 200 kg/m3 is preferably used, and even fire barriers 6 with an apparent density of 80 kg/m3 may be sufficient for some applications. It is also possible to use heavier fire barriers 6 with an apparent density of, for example, 300 kg/m3, depending on the particular requirements.

(34) Moreover, it is also unnecessary for the fire barriers 6 and 6′ to be pressed into the insulation layer 3. They may also be arranged herein, for example, with a clearance and fastened by an adhesive or the like.

(35) It is also not necessary in this connection for the fire barrier 6 to be fixed on the external wall 2 by, for example, bonding. For example, the clamping effect between the facade insulation panels 31 of the insulation layer may thus also be sufficient to ensure sufficient stability of the fire barriers 6. As an alternative, the fire barrier 6 may also be fixed mechanically, e.g., by means of suitable fastening components, profiles or the like.

(36) Further, it is also unnecessary for the fire barrier 6 to consist of mineral wool. An especially fireproof glass wool or even slag wool or the like may also be used for this.

(37) The mineral wool of the fire barrier 6 does not, moreover, need to have a laminar fiber structure. This mineral wool may also be different, so that it is possible to use especially compressed fiberboards.

(38) Further, it is possible that the fire barrier 6 additionally has an intumescent coating. This leads to a further increase in the fire protection effect. In addition to or instead of the intumescent coating, it is also possible to take other fire-retardant measures, such as the use of dehydrating additives or the like.

(39) It is further possible that the fire barrier 6 additionally has a coating intended for weather protection in order to protect especially the fire barrier 6 from water entering into the rear ventilation gap 5.

(40) If the insulation layer 3 has a sufficient fire protection effect, it may also be sufficient if the fire barrier 6 extends only from the outer side of the insulation layer 3 to the facade cladding 4.

(41) The fire barrier 6 may be manufactured in the factory with an oversize, in which case it is then cut to the corresponding dimension between the external wall 2 and the facade cladding 4 at the time of the installation on the building facade 1 according to the present invention. It is unnecessary in this case to manufacture special custom-made fire barriers 6 in advance. In addition, adaptation to the special on-site conditions is possible without problems.

(42) It is not necessary for the slot 32 to be formed in the insulation layer 3 by being cut into this layer. The insulation panels 31 may, instead, also be positioned on the external wall 2 in the course of the installation such that the slot 32 is obtained as a free space between these at the predetermined locations.

(43) If, however, the slot 32 is cut into the insulation layer 3, its depth is to be selected in a suitable manner depending on the conditions prevailing at the concrete building.

(44) It is not absolutely necessary in some applications for the insulation material to be removed from the slot 32. It can possibly be displaced when the fire barrier 6 or 6′ is being pressed in.

(45) As an alternative, the slot 32 may also be formed in one operation by milling the material out of the insulation layer 3.

(46) The facade insulation panels 31 of the insulation layer 3 may also be formed from a material other than the mineral wool mentioned above. It is thus possible to use other suitable insulating fiberboards or insulation panels consisting of an incombustible material.