[0001] The invention relates to a ventilated and fire-safe structure, equipped with a fire-safe
windscreen and intended for buildings, such as e.g. apartment and commercial buildings,
where non-inflammability is required of the windscreen.
Prior art
[0002] In prior art, it is known to provide protection against the wind by using so-called
"non-woven" fabrics, i.e. fiber fabrics, as a windscreen for mineral wool products
to be installed on external building walls.
[0003] In prior art solutions, the wind protection is comprised of a combination of fiberglass
felt and paint or of a special fabric alone. These prior art solutions are basically
functional, but do involve shortcomings. First of all, they have poor fire characteristics,
i.e. burn too easily. Secondly, the application thereof on the surface of an insulating
material requires a separate gluing process, i.e. a separate glue matter. Accordingly,
there is a demand for novel, sufficiently moisture-permeable windscreens, which are
non-inflammable, structurally simpler, and capable of being installed on the surface
of an insulating material in a simpler manner.
[0004] DE1683498 A discloses a fire-safe ventilated structure for a building, which as an inner wall
cladding comprises a concrete element and a mineral wool layer, which is bonded to
an external side of the concrete element, as well as a façade element which is secured
by means of fasteners and spacers through the insulation to the inner concrete cladding
so as to leave between the facade element and insulation an air gap necessary for
ventilation. However, the solution in
DE1683498 A does not involve any windscreen, particularly not a moisture-permeable windscreen,
which is non-inflammable and installed on the surface on the mineral wool layer.
Description of the invention
[0005] A solution to the foregoing prior art problems has been provided by inventing a fire-safe
ventilated structure for a building, which as an inner wall cladding comprises a concrete
element and a mineral wool layer, which is bonded to an external side of the concrete
element and which on its external side has a hardened windscreen applied in a mortary
state to the mineral wool layer and being permeable to moisture and non-inflammable,
as well as a façade element which is secured by means of fasteners and spacers through
the windscreen and the insulation to the inner concrete cladding so as to leave between
the façade element and the windscreen coating an air gap necessary for ventilation.
[0006] The fire-safe ventilated structure for buildings, provided by the invention, fulfils
the requirements regarding both adequate ventilation and fire safety. For apartment
and commercial buildings, in particular, the solution presented by the invention provides
an important service because of its non-inflammability. The risks of fire spreading
and damage caused thereby are particularly high in apartment and commercial buildings
and, thus, the structure of the invention serves a useful purpose especially in that
type of buildings.
[0007] According to one preferred embodiment, the windscreen consists of a mineral-based
material. In its preferred service as a coating, the windscreen is firmly attached
to the fibers of the insulating material, conforming to the insulation material's
surface, i.e. being laminated therewith. The air blocker coating used in a ventilated
structure of the invention does not allow the entry of air flows in adverse amounts
while, on the other hand, it does allow the passage of water vapor the way a proper
windscreen is supposed to work.
[0008] According to another preferred embodiment, the windscreen material consists of backing
coat plaster. Other material options include artificial-resin based, acrylic or organic
adhesives.
[0009] All of the windscreen substances, mentioned above and useful in this invention, are
non-inflammable and can be applied manually or with a spray gun and, regarding the
material characteristics thereof, all these are elastic and contain fibers. According
to one preferred option, the windscreen substance can be applied to the insulating
material as early as in the concrete element casting process, by laying an amount
of such material on the bottom of a mould, upon which is then placed a layer of insulating
material, with a cast concrete layer being added on top of the latter. On the other
hand, according to another embodiment, being applied manually or with a spray gun,
the windscreen substance can be bonded to the surface of a concrete cladding element
insulating material for example at the factory or worksite.
[0010] As stated above, the question is about a ventilated structure, the inner wall cladding
of which comprises a concrete element and a rock wool product (a panel or a lamella,
meaning that wool fibers are either parallel with the insulating panel's surface or
orthogonal with respect to the insulation surface), preferably bonded thereto at the
factory during the course of the casting process. Alternatively, of course, the insulation
layer can be bonded to the concrete cladding element with a variety of fastening elements.
A problem with such assemblies is that the surface of an unprotected thermal insulating
material is exposed to flowing air and allows such air flows inside, thus affecting
the product's heat insulation performance. In order to deal with this problem, the
insulation layer is covered with a windscreen coating. In the event that a mineral
wool insulating material, preferably rock wool, is coated with a windscreen coating
at the factory, the coating of sealed joints will be performed consequently at the
worksite by using the same substance. The actual façade is mounted either at the factory
or at the worksite with separate fasteners and spacers through the insulating material
and the windscreen to the inner concrete cladding, thus leaving between the façade
element and the windscreen-coated insulation surface an air gap needed for ventilation.
[0011] Regardless of whether the windscreen is applied in a mould on the insulating material
of concrete cladding elements to be cast during the casting of a concrete cladding
element or on the surface of the insulating material at the factory or worksite after
an embedding process of the concrete in the insulating material has been performed
in a mould, this windscreen is nevertheless constructed without a separate core or
without a separate gluing process and glue matter. This is possible because the windscreen
coating, capable of being applied, sprayed or bonded in a mortary state (contains
e.g. water), possesses gluiness/mortariness, whereby the bonding to the insulating
material occurs during the course of its drying, thus establishing a uniform windproof
surface/coating on the heat insulating material of mineral wool (e.g. rock wool).
Notwithstanding its alkalinity, the windscreen material is apt for use with rock wool
as rock wool has resistance to alkali. During its application process, the windscreen
coating is a wet mortary substance as opposed to the currently available materials
which consist of fabric or panel products.
Working example
[0012] The invention will now be described more specifically by way of example with reference
to the figure 1 of principle, which shows a fire-safe ventilated building structure
of the invention in a cross-sectional view as seen from the top of such a structure
in an assembled condition. The presently described example is not to be construed
as limiting our invention which is defined in the claims.
[0013] In a ventilated building structure 7 as shown in fig. 1, the inner wall cladding
comprises a concrete element 1, to which is bonded, during the course of its casting,
an insulation layer of rock wool 8, which consists of several lamellae of rock wool.
The insulation layer 8 has its outer surface provided with a windscreen coating 3
made up of hardened backing coat plaster. This material, i.e. backing coat plaster,
applicable as the windscreen coating 3, is bonded to the insulation layer 8 during
the course of casting the concrete element 1 by first laying backing coat plaster
for the layer 3 on the bottom of a mould, then on top of that the insulation layer
8 of rock wool lamellae, followed by casting the concrete layer 1 for a final and
topmost layer.
[0014] Alternatively, the windscreen coating 3 is not bonded until after embedding of the
concrete 1 with the insulation 8 has taken place in a mould, in which case the windscreen
material is applied to the insulation layer by spraying or grinding it onto the insulation
surface either at the fabrication plant of concrete elements or at the worksite.
[0015] In this example, the ventilated structure according to the invention is ultimately
completed at the worksite, wherein an actual façade 4 is secured to the concrete element
1 included in an entity consisting, as described above, of the mutually bonded concrete
cladding 1, the insulation 8, and the windscreen coating 3, through the insulation
8 and the windscreen coating 3 by means of suitable fasteners 5. Interposed between
the windscreen coating 3 of the insulation 8 and the façade are suitable spacers 6
to provide a space between the façade 4 and the coating 3 for an air gap 9 needed
for ventilation.
Air Permeability test for mortar-coated rock wool products
1 Specimens and measuring method
[0016] Specimen size was 300 mm x 300 mm x specimen thickness. Top edges of the specimens
were taped with duct tape to make the edges of specimens intact and to improve the
compactness of specimens in a measuring apparatus. With such a procedure, the resulting
surface area of a measured region was 0.0784 m
2 as opposed to normally employed 0.09 m
2.
[0017] The measurement was conducted by applying the EN 29053 method. Air flow rates used
in the measurement of each specimen were 0.3 l/min, 0.7 l/min, and 1 l/min.
[0018] The employed products consisted of rock wool.
2 Results
| Specimen |
Wool weight/g |
Coating weight/g |
L-value 10-6 m3/m2sPa |
To be noted |
| 1 |
509.3 |
392.2 |
16 |
|
| 2 |
542.0 |
662.1 |
17 |
Coating has a 10 cm crack |
| 3 |
563.1 |
539.8 |
21 |
|
| 4 |
525.7 |
337.8 |
16 |
|
| 5 |
538.9 |
176.4 |
16 |
|
| 6 |
525.8 |
171.7 |
21 |
|
[0019] Thus, the results indicate that the mortar coating has an air permeability factor
acceptable in buildings (L-value < 25 x 10
-6 m
3/m
2sPa) and that, consequently, it functions quite well as a windscreen in external wall
structures, which are provided with a ventilation opening or gap between an insulating
material coated with this windscreen and an actual façade.
1. A fire-safe ventilated structure (7) for a building, which as an inner wall cladding
comprises a concrete element (1) and a mineral wool layer (8), which is bonded to
an external side of the concrete element and which on its external side has a hardened
windscreen coating (3) applied in a mortary state to the mineral wool layer and being
permeable to moisture and non-inflammable, as well as a façade element (4) which is
secured by means of fasteners (5) and spacers (6) through the windscreen coating (3)
and the insulation (8) to the inner concrete cladding (1) so as to leave between the
façade element (4) and the windscreen coating (3) an air gap (9) necessary for ventilation.
2. A structure (7) as set forth in claim 1, wherein the windscreen coating (3) consists
of a mineral-based material.
3. A structure (7) as set forth in claim 2, wherein the mineral-based substance consists
of backing coat plaster.
4. A structure (7) as set forth in any of claims 1-3, wherein the insulation (8) is applied
to the inner cladding element (1) of concrete during the course of casting the concrete
element.
1. Feuerfeste belüftete Struktur (7) für ein Gebäude, die als Innenwandverkleidung ein
Betonelement (1) und eine Mineralwolleschicht (8) umfasst, welche mit einer Außenseite
des Betonelements verbunden ist und auf ihrer Außenseite eine gehärtete Windschutzbeschichtung
(3) aufweist, die in einem Mörtelzustand auf die Mineralwolleschicht aufgebracht und
feuchtigkeitsdurchlässig und nicht entflammbar ist, sowie ein Fassadenelement (4),
das derart mittels Befestigungselementen (5) und Distanzstücken (6) durch die Windschutzbeschichtung
(3) und die Isolierung (8) an der inneren Betonverkleidung (1) befestigt ist, dass
zwischen dem Fassadenelement (4) und der Windschutzbeschichtung (3) ein Luftspalt
(9) belassen ist, welcher zur Belüftung notwendig ist.
2. Struktur (7) nach Anspruch 1, wobei die Windschutzbeschichtung (3) aus einem mineralbasierten
Material besteht.
3. Struktur (7) nach Anspruch 2, wobei die mineralbasierte Substanz aus Rückseitenbeschichtungsmörtel
besteht.
4. Struktur (7) nach einem der Ansprüche 1 bis 3, wobei die Isolierung (8) auf das innere
Verkleidungselement (1) aus Beton im Verlauf des Gießens des Betonelements aufgebracht
wird.
1. Structure ventilée et anti-feu (7) destinée à un bâtiment, qui en tant qu'habillage
de paroi intérieure comprend un élément en béton (1) et une couche de laine minérale
(8) qui est collée à un côté extérieur de l'élément en béton et qui présente sur son
côté extérieur un revêtement de brise-vent durci (3) appliqué dans un état au mortier
sur la couche de laine minérale et étant perméable à l'humidité et ininflammable,
ainsi qu'un élément de façade (4) qui est fixé au moyen de fixations (5) et d'écarteurs
(6) à travers le revêtement de brise-vent (3) et l'isolation (8) vers l'habillage
de paroi intérieure (1) de façon à laisser un espace d'air (9) nécessaire à la ventilation
entre l'élément de façade (4) et le revêtement de brise-vent (3).
2. Structure (7) selon la revendication 1, dans laquelle le revêtement de brise-vent
(3) consiste en un matériau à base minérale.
3. Structure (7) selon la revendication 2, dans laquelle la substance à base minérale
consiste en du plâtre à enduit au verso.
4. Structure (7) selon l'une quelconque des revendications 1 à 3, dans laquelle l'isolation
(8) est appliquée sur l'élément d'habillage intérieur (1) de béton pendant la coulée
de l'élément en béton.