HEAT INSULATING ELEMENT, BUILDING CONSTRUCTION AND METHOD FOR AVOIDING MOISTURE DAMAGE AT A BUILDING

Abstract

The invention relates to a heat insulating element (4) for an interior insulation, a facade insulation, a roof insulation, or the like at a building (1), comprising an insulating body (41) which is of diffusion-open design. The heat insulating element (4) is characterized in that it further comprises a fabric (42), especially a fleece, which is of capillary-active design, and that the fabric (42) is arranged on a surface of the insulating body (41). Furthermore, the invention relates to a building construction, to a method for avoiding moisture damage at a building (1), and to the use of a heat insulating element of this type. This achieves an improved heat insulating element (4) for avoiding moisture damage at a building (1) by means of which it is possible to accelerate drying of the region concerned in the case of the accumulation of water, especially condensation water, with simple means. Furthermore, an appropriate building construction is provided in which moisture damage can be avoided more reliably, and an improved method for avoiding moisture damage at a building (1) is provided.

Claims

1. A heat insulating element (4) for an interior insulation, a facade insulation, a roof insulation, or the like at a building (1), comprising an insulating body (41) which is of diffusion-open design, characterized in that the heat insulating element (4) further comprises a fabric (42), especially a fleece, which is of capillary-active design, and that the fabric (42) is arranged and laminated on a surface of the insulating body (41).

2. The heat insulating element according to claim 1, characterized in that the fabric (42) comprises a capillarity for water with a capillary rise of more than 15 cm, preferably more than 20 cm.

3. The heat insulating element according to claim 1, characterized in that the fabric (42) is formed of glass fibers or plastic fibers.

4. (canceled)

5. The heat insulating element according to claim 1, characterized in that the insulating body (41) has a value of 3, preferably a value of 2.

6. The heat insulating element according to claim 1, characterized in that the insulating body (41) is formed of mineral wool or natural fibers, especially soft wood fibers.

7. A building construction with a separator between an inner side and an outer side of a building (1), wherein the inner side corresponds to a warm side of the building (1) and the outer side corresponds to a cold side of the building (1), and with a plurality of heat insulating elements (4) for an interior insulation, a facade insulation, or the like at said building (1) further comprising an insulating body (41) which is of diffusion-open design, characterized in that the heat insulating element (4) further comprises a fabric (42) which is of capillary-active design, and that the fabric (42) is arranged and laminated on a surface of the insulating body (41).

8. The building construction according to claim 7, characterized in that the separator is a wall element (3) and the heat insulating elements (4) form an interior insulation, wherein the fabric (42) is arranged to face the wall element (3).

9. The building construction according to claim 7, characterized in that the separator is a wall element (3) and the heat insulating elements (4) form a facade insulation, wherein the fabric (42) is arranged to face away from the wall element (3) toward the outer side.

10. The building construction according to claim 7, characterized in that the separator is a roof structure (2) and the heat insulating elements (4) form a roof insulation, wherein the fabric (42) is arranged to face away from the roof structure toward the outer side.

11. (canceled)

12. A method for avoiding moisture damage at a building (1) comprising a separator such as a wall element (3; 3) or a roof structure (2) and equipped with heat insulating elements (4) for an interior insulation, a facade insulation, or the like at said building (1) further comprising an insulating body (41) which is of diffusion-open design, wherein the separator is arranged between an inner side and an outer side of a building (1), wherein the inner side corresponds to a warm side of the building (1) and the outer side corresponds to a cold side of the building (1), wherein the method comprises the steps of: occurring of a moisture accumulation in the region of the fabric (42), extensively distributing the moisture due to the capillary-active property of the fabric (42) for increasing the area of evaporation, guiding off the moisture by evaporation and thus drying the area concerned of the fabric (42).

13. The method according to claim 12, characterized in that the moisture is guided off by means of diffusion through the diffusion-open insulating body (41).

14. The method according to claim 12, characterized in that the moisture is guided off by evaporation from the side of the fabric (42) which faces away from the insulating body (41).

15. Use of a heat insulating element according to claim 1 for an interior insulation, a facade insulation, a roof insulation, or the like at a building (1).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In the following, the invention will be explained in detail in embodiments by means of the Figures of the drawing. There show:

[0042] FIG. 1 a section through a roof structure of a building which is designed in accordance with the invention;

[0043] FIG. 2 a section through a roof structure of a building which is designed conventionally as compared to FIG. 1;

[0044] FIG. 3 a section through a wall element with exterior insulation designed in accordance with the invention;

[0045] FIG. 4 a section through a wall element in accordance with the invention pursuant to a further embodiment with an interior insulation;

[0046] FIG. 5 a perspective view of a heat insulating element in accordance with the invention with accumulated moisture; and

[0047] FIG. 6 a diagram for comparing the drying period of heat insulating elements with and without capillary-active fabric.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0048] FIG. 1 illustrates a building 1 with a roof structure 2 designed in accordance with the invention. For comparison, a conventional roof structure D is illustrated in FIG. 2. FIGS. 3 and 4 illustrate wall elements 3 and 3 which are designed in accordance with the invention.

[0049] Pursuant to the sectional illustration in FIG. 1 the roof structure 2 comprises a roof covering 21 and a sub construction 22 therefor. Therebelow is positioned a sarking membrane 23 which covers an over rafter insulation formed of heat insulating elements 4. At the outer side the over rafter insulation rests on rafters 24 between which a between rafter insulation 25 is disposed. A vapor barrier 26 and a sheathing 27 form the inner-side termination.

[0050] Each heat insulating element 4 comprises an insulating body 41 of mineral wool and a capillary-active fabric, in particular a fleece 42 of glass fibers. The fleece 42 is laminated on the insulating body 41 and is available at the outer side in the direction of the sarking membrane 23.

[0051] In the illustrated embodiment the sarking membrane 23 comprises a defect S through which moisture may penetrate onto the over rafter insulation.

[0052] For comparison, FIG. 2 illustrates the conventional roof structure D which differs from the structure of the building construction pursuant to FIG. 1 only by the fact that, instead of the heat insulating element 4, a conventional, non-laminated mineral wool plate is disposed as an element of the over rafter insulation. Also in the arrangement pursuant to FIG. 2 a defect S is available in the sarking membrane.

[0053] As is shown in the illustration in FIG. 2, moisture enters through the defect S into the mineral wool of the over rafter insulation and damages the structure thereof. The moisture distributes conventionally in correspondence with the usual behavior of water substantially in a drop-shaped manner and is accumulated in the region of the defect S. Therefore, the water can dry only very slowly.

[0054] In the roof structure 2 in accordance with the invention pursuant to the illustration in FIG. 1 the insulating body 41 is, on the contrary, laminated with the fleece 42 which is of capillary-active design. The water entered through the defect S distributes along the fleece 42 and covers accordingly a larger area than in the state of the art. No water accumulation as it is known from the state of the art will occur. For this reason, the moisture dries from the heat insulating element 4 substantially more quickly and diffuses on a large face to the outside through the sarking membrane 23.

[0055] FIG. 3 illustrates a section through the wall element 3 of the building 1 which is provided with an exterior insulation. It comprises at the inner side a plaster layer 31 which is applied on a supporting wall 32. At the outer side there follows the exterior insulation of heat insulating elements 4. The insulating body 41 rests on the wall 32 while the capillary-active fleece 42 laminated thereon is arranged on the side of the insulating body 41 which faces away from the wall 32. On the fleece 42, finally, an exterior plaster 33 is arranged.

[0056] The illustration in FIG. 3 further illustrates by means of a line A the temperature profile in the wall element 3 during the heating period across the wall thickness. With the line B the dew point in the wall element 3 is further illustrated. Since the insulating plane of this exterior wall insulation is available outside of the wall 32, no accumulation of condensation water will occur here as a rule.

[0057] It is, however, possible that the exterior plaster 33 is damaged due to external influences or the like and that moisture may thus penetrate into the wall element 3. There, however, this moisture encounters first of all the capillary-active fleece 42 which distributes the moisture directly to a larger face and thus favors the drying thereof. Since the moisture entry typically takes place here and there and only in the case of rain showers, for instance, the time of rain breaks will frequently suffice to achieve a uniform dissipation of moisture across a larger area into the exterior plaster and thus to the environment. Damage of the insulating body 41 can thus be avoided reliably.

[0058] FIG. 4 shows the wall element 3 provided with an interior insulation. Here, too, a plaster layer 31 is available at the inner side, which is, however, followed by the interior insulation formed of heat insulating elements 4. The insulating body 41 is positioned adjacent to the plaster layer 31 while the capillary-active fleece 42 is arranged at the side of the insulating body 41 which faces a wall 32. At the outer side the wall structure is terminated by an exterior plaster 33.

[0059] Also in this illustration is the temperature profile through the wall element 3 shown by means of a line A. Likewise, the dew point is plotted by means of a line B. As is shown in the illustration, the temperature drops strongly within the interior insulation while it experiences only little cooling in the wall 32. The wall 32 is available outside of the insulating plane, which results in that condensation water may accumulate at the boundary surface between the wall 32 and the fleece 42 especially during the heating period. Conventionally, the condensation water would accumulate in this area especially at corners and places of joint, and would lead to mold formation or the like.

[0060] By the capillary-active fleece 42 possibly existing moisture is, however, distributed across a large face, so that it can dry easily and quickly. This takes place through the diffusion-open insulating body 41 via the plaster layer 31 into the interior of the building 1.

[0061] FIG. 5 illustrates a perspective view of a portion of the heat insulating element 4. In the foreground, the capillary-active fleece 42 is illustrated, which is only laminated on a large face on the insulating body 41. As a fleece 42 the product known under the brand name EVO 170 is used.

[0062] In the illustrated example the heat insulating element 4 rests against a corner region, for instance, in a window reveal where condensation water T accumulates. The water accumulates directly in the corner, but is then sucked in by the capillary-active fleece 42 and distributed across a larger face F. From there it may dry quickly and may be discharged through the diffusion-open insulating body 41.

[0063] Laboratory tests concerning the drying behavior in the corner region of a window reveal as a worst case scenario have shown that in this manner a quite substantial acceleration of the drying process may be achieved. FIG. 6 illustrates in a diagram the drying period in hours, wherein a sample with a fleece 42 is plotted with the line M and a sample without the fleece 42 with the line O. The drying period was ascertained by determining the change in mass of the sample since this proceeding appeared suitable to be able to reliably ascertain the remaining moisture content of the sample. The qualitative difference between the sample with the fleece 42 and the sample without the fleece 42 can be recognized directly.

[0064] The success of the distribution of moisture on a large face depends predominantly on the capillarity of the fleece 42. The suction distance and the suction velocity of the fleece 42 play an important role here. These parameters depend less on the material of the fleece, but rather on the weaving technique and/or the geometry of the fibers which cooperate here.

[0065] Capillarity describes the rising or sucking process of a liquid when getting into contact with narrow tubes (capillaries) or small cavities. The liquid will in this case distribute to a larger face and rise even against gravity. This effect occurs due to the molecular forces in the liquid and the surface tension involved therewith. In the instant application this liquid is as a rule water which is characterized by a large surface tension. Two factors play a quite substantial role here, namely cohesion and adhesion.

[0066] Cohesion is the cohering force of the molecules in a body. In a liquid the cohesive forces are so small that the molecules may move within the liquid. Adhesion is the attraction force between the molecules of two different substances.

[0067] If the liquid meets a solid surface and the adhesive forces between this surface and the liquid are stronger than the cohesive forces of the liquid, the liquid will attempt to wet the surface. In this process the molecules of the liquid are attracted by the adhesive forces by the surface of the solid body. Due to the cohesive forces, molecules which were attracted by the surface will drag along the remaining molecules. Thus, a meniscus will form at the contact face, i.e. the liquid will rise at the wall.

[0068] The capillary rise of a liquid may be calculated by means of the following equation:

h=2 cos /gr

wherein: [0069] h=capillary rise of the liquid [0070] =surface tension [0071] =contact angle [0072] =density of the liquid [0073] g=gravitational acceleration [0074] r=radius of the capillaries

[0075] At 20 C. the surface tension for water is 72.75 mN/m. Apart from this the density of water and the acceleration are also constant. If one assumes a contact angle of 0, a value of 1 will result for the factor cos . Thus, the radius of the capillaries r remains as the only variable in this equation.

[0076] In the fleece 42 this factor r is determined by the cavities and the weaving structure, from which appropriate capillary rises of water can as a rule be determined by experiments for different fleeces. In the instant embodiments fleeces with a capillarity for water with a capillary rise of more than 15 cm have turned out suitable. If a higher value is chosen, the effect of distribution of the liquid on a larger face is the more distinct.

[0077] In addition to the embodiments explained, the invention allows for further design approaches.

[0078] Thus, it is not mandatorily necessary that the capillary rise of the fleece 42 is more than 15 cm. For some applications a lower capillary rise of e.g. 10 cm may also be sufficient.

[0079] Furthermore, the fleece 42 need not be made of glass fibers. Instead, plastic fibers or mixtures of different kinds of fibers may also be used. Also the kind of weaving of the fleece 42 may be arbitrary per se as long as it is of capillary-active design. Thus, the fleece 42 may, for instance, also be a fleece EVO 130, an Ortmann fleece, or any other suitable capillary-active fleece.

[0080] Furthermore, it is not necessary that the fleece 42 is laminated on the insulating body 41. It may also be connected therewith by a needling process or simply be arranged loosely next to it.

[0081] The insulating body 41 comprises a water vapor diffusion resistance of 3. In order to improve the diffusion capacity, a lower value may, however, also be chosen, for instance, equal to 2.

[0082] In the illustrated embodiment the insulating body 41 is formed of mineral wool. Instead, other types of fiber and especially natural fibers such as, for instance, soft wood fibers or the like, may also be used. Mixtures of such fibers are also possible.