EP2225426A2 - System for insulating buildings from the outside - Google Patents

Abstract

The invention relates to a system for insulating buildings from the outside that comprises an insulator (1) covered with cladding plates (2), characterised in that the steam diffusion resistance of the cladding plates (2) and of the other optional constituents of the insulating system covering the same, corresponds to an equivalent air thickness Sd not exceeding 0.40 m, preferably 0.30 m and most preferably 0.20 m. The system has sufficient breathability to avoid the long and costly construction of a ventilated facade.

Description

 OUTDOOR BUILDING INSULATION SYSTEM

The present invention relates to a system of external insulation of buildings, preferably non-industrial masonry wall, or brick, or solid or light concrete.

This is to thermally and / or acoustically isolate the facades of buildings that may comprise several floors.

In a first known system, the insulation consists of rigid panels of mineral wool, usually rock wool, or organic foam, usually expanded polystyrene.

These panels are glued to the outer wall of the building to be insulated, and generally receive point mechanical retention elements of the type expansive peg especially for the high walls. The insulating panels are then covered with an organic or mineral finish coating, usually with the interposition of a reinforcing interlayer such as a glass or plastic grid.

In this system, the panels must be rigid because they are the ones that bring the mechanical properties of the facade cladding. An acceptable resistance to the pressure / vacuum forces due to the wind is obtained thanks to the bonding and the mechanical retaining means. The surface remains however subject to deterioration by depression or punching during an impact with a foreign body on the thin layer of surface coating.

Organic foam panels also have the disadvantage of being impervious to water vapor and therefore do not allow the diffusion of water vapor through the wall.

In general, bonding is disadvantageous in renovation because it requires a wall with flatness defects of less than a few millimeters per meter. In the case where the surface to be insulated is highly degraded, a preliminary repair is necessary, which is costly in time and materials. In addition, the glue can have a negative influence on the moisture exchange.

In another known system, the insulation is contained between frame elements fixed to the wall to be insulated, which may be wood or metal, and a outer facing is attached via a supporting structure defining at the rear of the facing a space enclosing an air gap connected to the outside. This system is commonly called "ventilated facade".

This construction avoids the risk of condensation and moisture accumulation in the facade, and thus the proliferation of microorganisms, algae or fungi. The wood frame is particularly concerned, because the wood is likely to deteriorate under the effect of moisture.

The disadvantage of ventilated facades lies in their complexity of implementation, especially at the singular points of the facade (doors, windows ...). In addition, in case of fire, the ventilation of the facade favors the spread of fire on the upper floors ("chimney effect").

The main purpose of the invention is the provision of an external breathable insulation system, that is to say, compatible with the natural tendency of the masonry walls to absorb and releasing moisture according to the seasons. , and whose implementation is simplified compared to conventional ventilated facades.

It also aims to develop a compact and lightweight external insulation system, which facilitates both its attachment to the wall and transport, the insulation can be in a compact form such as in rolls. It also aims to provide a system that can be more fire resistant, by the use of mineral wool in a configuration that can dispense with air space. The lack of air space limits the spread of fire in case of fire on the facade.

These objects are achieved by the invention which relates to a building insulation system from the outside comprising an insulator (1) covered with facing plates (2) characterized in that the resistance to the diffusion of steam of the water of the facing plates (2) and any other constituents of said insulation system covering them corresponds to an equivalent air thickness S _d at most equal to 0.40 m, preferably to 0.30 m, and in particular preferred at 0.20 m. The ability of a material to resist the diffusion of water vapor can be characterized by various factors. Its water vapor permeance represents the amount of water vapor passing through the material thickness per unit area, time and pressure. The permeance can be measured according to ASTM E 96, and expressed in "Perm" unit, defined as 5.7 × 10 ⁸ g. Pa ^"1. s ^{" 1} . m ^"2. The diffusion resistance of the steam is defined as the inverse of the permeability. The permeability, which is the product of the permeance of the thickness of the material, is in turn a characteristic The resistance to the diffusion of the water vapor of a material is also very often related to the resistance to the diffusion of the water vapor of a layer of air. resistance to the diffusion of water vapor as the ratio between the permeability of the air and the permeability of the material considered.It is then common practice to express the resistance to diffusion by multiplying this index by the thickness of the material considered, which is equivalent to dividing the permeability of the air to the water vapor by the permeance of the material in question.The result, expressed in meters and called "equivalent air thickness" (S _d ), thus corresponds to to the thickness of air having the same permeance to water vapor as the material thickness considered. The originality of the system according to the invention lies in the fact that the facing plates are considered as active elements in the mechanism of diffusion of water vapor, whereas this function was heretofore carried out by an air knife inserted in the system. In this regard, the inventors have considered the breathability vis-à-vis the water vapor facing plates and layers covering them as essential. Thanks to the characteristics of the insulation system of the invention, the exchange of water vapor through the insulated wall of the building is possible following the alternation of cold periods (condensation of moisture) and hot (evaporation). Thus in the system of the invention, water vapor is likely to penetrate the insulation during cold seasons, then to be released during the hot seasons.

In combination with a judicious choice of insulation, this breathability makes it possible to dispense with an air gap. However, the presence of an air gap is not incompatible with the invention. We reduce the size and weight of the insulation system, while avoiding the formation of microorganisms, algae, fungi, molds ... The installation of the insulation system is simpler and faster.

The facing plates are preferably mineral material plates resistant to humidity or adapted to use in damp rooms, particularly meeting the H1 classification. They may in particular be based on a hydraulic setting binder such as plaster in the form of a plate and / or in the form supported on a rib expanded metal reinforcement or a metal mesh or other covered in both cases with a thick mortar. This may consist for example of cement, be breathable by the fact that its porosity is high. Plasterboard or thick mortar may optionally include fillers and reinforcements including synthetic material in the form of beads (polystyrene or expanded clay), fiber Some plasterboard in particular, are remarkable for several reasons. They are breathable vis-à-vis the water vapor. In addition, these plates improve the fire resistance of the system (in addition to mineral wool), and sound insulation by the principle of "mass-spring-mass", here represented by "plate-mineral wool-wall".

Fractions of their thickness can be modified to increase their resistance to water, modified with the polymer, reinforced mechanically by embedding glass mats for example. In an advantageous embodiment, the plasterboards have a plaster core resistant to moisture and a surface reinforced by a glass mat covered with a polymer coating of acrylic type. Such plates are described in documents US Pat. Nos. 6,524,679, WO 2007,004,066 and WO 02,098,646. Thus, the resistance to diffusion of water vapor from a 12.5 mm thick plasterboard. corresponds to an equivalent air thickness S _d not exceeding 0.10 m or even 0.08 m.

The plasterboard is also available in dimensions of 1200 x 1200 x 12.5 mm in particular, advantageous for transport. Examples of products that can be used according to the invention are plasterboard marketed by CertainTeed under the trademark GlasRoc. An air gap, if necessary ventilated, can be interposed between the insulation and the cladding.

In the absence of such an air gap, the facing, that is to say either the gypsum board is the thick mortar covering the expanded metal rib or the metal mesh, as well as the other components of the system. insulation covering the siding (including base coat, finishing coat), must be breathable.

In all cases, the insulation may or may not be directly covered with a rain barrier preventing liquid water to pass, but allowing water vapor to pass. The rain cover therefore consists of a breathable film, an example of which is marketed by Du Pont de Nemours under the registered trademark.

Tyvek.

Said constituents of said insulation system covering the facing plates preferably consist of a base coating, a fabric or grid sheet and a coating, and are in bonding relationship with each other as well as with the coating plates. facing.

When the facing is plaster, the base coating is preferably cementless, especially organic - that is to say completely organic - to prevent the formation of ettringite. The fabric web or grid advantageously comprises alkali-resistant glass fibers. It has a function of reinforcing and supporting the coating, so that it no longer shows the lines of separation between neighboring facing plates.

The coating is advantageously chosen from a silicate and / or silicone coating. It provides a combination of high performance in water vapor diffusion (breathability), impact resistance, flexibility (risk of cracking), resistance to water (rainwater), ultraviolet radiation, algae , dust, industrial pollution (fumes, acid rain), fire (non-flammability). The insulation is preferably a mineral wool, especially glass wool, having a density of between 7 and 100 kg / m ³ , and particularly preferably at most equal to 50 kg / m ³ , in particular between 7 and 50 kg / m ³ or 7 and 40 kg / m ³ , for example of the order of 10 to 30 kg / m ³ . Advantageously, the insulator has a thermal conductivity (λ) of the order of 30 to 40 mW / mK, preferably 30 to 35 mW / mK.

It is a thermally and acoustically insulating product. It allows drying of the construction, it is able to absorb and releasing moisture to a certain extent, with the seasons, without being affected in any way in its nature and its integrity, nor in its insulating functionality.

It is therefore not a barrier to moisture, so that no microorganism, algae, fungus - mold is formed. No air space is useful here, in order to create a circulation of air and humidity. In addition mineral wool is a light product, compressible and especially transportable in compact form (rollers ...). This insulation is not rigid, but rather compressible, which allows the easy positioning of wires, ducts, cables, pipes or pipes in the insulation, and its rapid cutting.

The insulation and the facing are preferably supported and maintained by the combination of a set of first brackets fixed to the wall to be insulated, and profiles fixed to the first consoles and having a flat bearing surface of the facing plates.

Here means "console" means capable of ensuring for decades the support and maintenance of the loads to which the facade is subject.

The insulation system of the invention is lightweight, and perfectly compatible with significant heights of facades.

Profiles whose function is to guarantee the maintenance, the fixation, the rigidity and a high quality mechanical strength, may be metallic, provided that they have a minimum resistance to corrosion in the exterior (aluminum or Z275 steel), of polymer material possibly reinforced, or the like.

In a first variant, the profiles are fixed directly to the first consoles. The insulation rests on these, and is confined in the space delimited by the wall to be insulated, the first consoles and the profiles.

In a second variant, said profiles are fixed to said first consoles via as many seconds consoles.

According to a preferred characteristic, said profiles are T or L whose the foot portion is intended to be in register with a part of said first consoles or second brackets, and the head portion constitutes said flat bearing surface of said facing plates. On the other hand, said first consoles are advantageously made of reinforced plastic with low combustibility, and in particular obtained by extrusion or pultrusion processes. Many polymers or copolymers are suitable, for example based on isophthalic resin, polyester, polyamide, polypropylene or other polyolefins, acrylic polymers ... The reinforcement is advantageously made by glass fibers.

The plastic material has an interesting property of thermal insulation, as thermal breaker which would be established with other materials, especially metal, between the wall to be insulated and the new facade formed by the profiles and plates. The invention will be better understood in the light of the accompanying drawings, in which FIG. 1 is a general perspective representation of the insulation system of the invention viewed "from the inside", that is to say from the wall to isolate; - Figures 2 and 3 are detailed perspective views of the elements for the support, maintenance and fixing of the mineral wool and facing plates,

these elements being in the mounting position in FIG.

- Separated exploded view in Figure 3. The thermal and acoustic insulation of an outer wall not shown essentially comprises a glass wool mat (1) and plasterboard (2). The glass wool (1) has a density of 23.5 kg / m ³ and a thermal conductivity λ of 33 mW / mK The mattress is available in rolls of 1200 mm in length (width of a lé). Once unrolled and decompressed the mattress exists in several thicknesses, including 50, 80, 100, 120 and 150 mm.

The facing plates (2) are lightweight plates that are permeable to water vapor, essentially based on mineral material including gypsum. The company's GlasRoc mineral facing plates (2) are used CertainTeed, of dimensions 1200 x 1200 x 12.5 mm; their mass per unit area is 9 kg / m ² ; it is significantly lighter than a cement slab with a surface density of about 13 to 14 kg / m ² . They preferably have a water-resistant core, covered on each side with reinforcements of glass mats embedded in a layer of polymer-modified plaster, itself each time covered with adhesion of an acrylic coating. Plasterboard plates known for this purpose are described in US Pat. No. 6,524,679 and WO 2007/004066.

These plates are easy to cut and use (saving time on installation), impact resistant, water resistant and vapor permeable. They support moisture well.

They do not contain paper or starch that could promote the development of mold.

They have good fire resistance, better wet dimensional stability than cement boards, and relatively high flexural strength (modulus of rupture greater than 12 MPa). In addition they are not friable unlike most fiber reinforced cement boards.

The plates (2) are screwed to the metal sections (5) by means of galvanized metal screws (not shown).

The mineral facing plates (2) are covered with a thickness of

5 mm of organic coating (base coat) marketed by the company

Weber and Broutin under the name "Webertherm Armierungsspachtel, zementfrei, Art. No. M708 ") in which is embedded a fiberglass reinforcing fabric, then a thickness of 2 mm silicate finish coating.

The joints between the plates are reinforced by mortar in the space between plates and reinforcement grid about 10 cm.

The diffusion resistance of the water vapor is measured in the form of the equivalent air thickness Sd (according to ASTM standard E96). - for plasterboard (2): 0,07 m; for finishing (base coat + fiberglass cloth + plaster): 0.14 m; for plasterboard (2) + finish: 0.18 m. These figures indicate excellent breathability of the separate and combined elements. They have an excellent synergy with glass wool, able to absorb and release moisture according to the frequency of the seasons, without damage, durably. In the embodiment shown in the three figures, the support and the maintenance of the insulation are mainly ensured by the cooperation of three types of elements: first brackets (3), second brackets (4) and metal sections (5). ).

The associations of first and second consoles (3, 4) are arranged every 1, 20 m, as well according to the height as to the width. Each first bracket (3) comprises a first substantially planar portion (31) intended to bear on the wall to be insulated, generally vertical, and a second substantially planar portion (32) perpendicular to the first (31) intended for a horizontal positioning so as to support the mineral wool (1) in particular.

The first bracket (3) is fixed to the wall by means of several screws (7) or equivalent (only one of which is shown), which can themselves be associated with pins introduced into the wall to be insulated. A third planar portion (33) connects the first (31) and the second (32) of the first bracket (3), which it intersects in two parallel straight line segments. This third plane portion (33) mechanically reinforces the first bracket (3), especially vis-à-vis the vertical loads to which it is subjected for several years, even several decades. The second planar portion (32) of the first bracket (3) is split to form a slot (34) for receiving the first planar portion (41) of a second bracket (4). The shape of the slot (34) is adapted to that of the first flat part (41) so that the depression of the latter is adjustable thereon, and that this depression is carried out with a certain resistance if necessary, the slot (34) can then be shaped to accommodate the first flat portion (41) with tightening. When the depression is adjusted as desired, fixing the first flat portion (41) of the second bracket (4) to the first bracket (3) is made by means of at least one screw (7).

The first console (3) is isophthalic resin reinforced with glass fibers and pultruded. It is essentially a low combustibility material (fire reaction A1). The thicknesses of the different flat portions (31, 32, 33) of the first bracket (3) are between 5 and 9 mm.

The second bracket (4) is made of galvanized metal 1, 5 mm thick. In addition to the first substantially planar portion (41), it includes a second (42) and a third (43), all three being perpendicular two by two.

It is visible in particular in Figure 3, that the aforementioned thickness of metal is doubled for the flat portions (41) and (43), the second bracket (4) being manufactured by a method of bending-stamping.

The third flat portion (43) connects the first planar portion (41) and the second (42), so that the structure of the second bracket (4) is reinforced.

The first flat portion (41) of the second bracket (4) is split into a slot (44) for receiving at least an end portion (51) of the metal section (5). Similarly, the third flat portion (43) is split into a slot (45) adapted to receive at least an end portion of another metal section (6) perpendicular to the metal section (5).

The shape of the slots (44), (45) is adapted to that of the profiles (5), (6), so that in particular the introduction of the second in the first is done with a certain tightening. Thus, their degree of depression can be regulated, if necessary.

The fastener itself is made by means of a screwing, for example in the second flat portion (42) of the second bracket (4) by means of screws (7).

The metal profile (5) is in T. The foot (51) of the T is intended to be in registration, overlapping with the first flat part (41) of the second bracket (4) (in this case, introduction into the slot (44)).

The head portion (52) of the T constitutes the flat bearing surface of the facing plates (2). It has return wings (53) towards the part foot (51) of the T, intended to be introduced into grooves (46) corresponding in the second flat portion (42) of the second bracket (4), so as to lock the metal section (5).

Grooves (11) are formed in the glass wool to prevent its compression - deformation by the protuberance of the second flat portion (42) corresponding to the back of the groove (46).

The metal profile (5) and / or the other metal section (6) can also be in L, while retaining most of the features of the T-sections described above. A metal L-shaped profile is practical to delimit all openings: door, bay, window ...

The wall attachment system described is reliable without the need for bonding the elements of the insulation, but instead avoiding the use of components that block the passage of moisture.

The insulation system described is light, easy to mount and fast, and has a satisfactory behavior in the accelerated aging conditions described in ETAG 004: no change in appearance or structural is observed after the cycles heat / rain and freeze / thaw. Satisfactory mechanical strength is maintained after these stresses. Its resistance to perforation and impact is also excellent.

Claims

An exterior building insulation system comprising - an insulation (1) covered with facing plates (2), characterized in that the resistance to the diffusion of water vapor from the facing plates (2) and any other constituents of said insulation system covering them corresponds to an equivalent air thickness S _d at most equal to 0.40 m, preferably 0.30 m and particularly preferably 0.20 m. 2. Insulating system according to claim 1, characterized in that the facing plates (2) are based on a hydraulic setting binder such as plaster, and / or expanded rib metal or a metal mesh covered with a thick mortar. 3. Insulating system according to claim 2, characterized in that the plasterboards (2) have a plaster core resistant to moisture and a surface reinforced by a glass mat covered with a polymer coating of acrylic type . 4. Insulation system according to one of the preceding claims, characterized in that said components of said insulation system covering the facing plates (2) consist of a base coating, preferably without cement when the facing is plaster , a cloth web or grid and a coating, and are in bonding relationship with each other as well as with the facing plates (2). 5. Insulation system according to claim 4, characterized in that the coating is silicate and / or silicone. 6. Insulation system according to one of the preceding claims, characterized in that the insulator (1) is a mineral wool of density at most equal to 50 kg / m ³ , preferably between 7 and 40 kg / m ³ , preferably a glass wool. 7. Insulation system according to one of the preceding claims, characterized in that the insulation (1) and the facing (2) are supported and maintained by the association a set of first consoles (3) fixed to the wall to be insulated, and profiles (5) fixed to the first consoles (3) and having a flat bearing surface (52) facing plates (2). 8. Insulation system according to claim 7, characterized in that said profiles (5) are fixed to said first consoles (3) via as many seconds consoles (4). 9. Insulation system according to one of claims 7 or 8, characterized in that said profiles (5) are T or L whose foot portion (51) is intended to be in coincidence with a portion of said first consoles (3) or second consoles (4), and the head portion (52) constitutes said flat bearing surface of said facing plates (2). 10. Insulating system according to one of claims 7 to 9, characterized in that said first consoles (3) are of reinforced plastic with low combustibility, preferably isophthalic resin.