Patent Description:
Various structures for designing building façades are known. The Rainscreen is most often used and may be referred to as rear-ventilated curtain façades or ventilated façades. The system possesses good protection for the load-bearing wall or building structure cladded therewith as well as providing ventilation and drainage.

Rainscreen systems are arranged onto a building structure or a load-bearing wall and comprises the façade cladding and a supporting sub-structure which carries the façade cladding onto the building structure. The system forms a rear ventilated cavity between the façade cladding and the building structure for ventilation, drainage, and pressure equalizing.

The ventilated façade cladding system is thus a two-step weather protective building envelope construction. It comprises the façade cladding or rainscreen cladding outermost, in combination with a fixing frame structure for carrying cladding attached to it, a windbreaker and inner temperature insulating layer of the building structure.

A Rainscreen is sometimes defined as the first layer of material of the wall, the siding itself. Rainscreen may also be defined as the entire system of the siding, drainage plane and moisture/air barrier. The Rainscreen is thus a part of the two-step protective construction that is used to form the exterior walls of buildings. In general terms a Rainscreen wall may be called a cavity or drained wall and is a wall that is ventilated.

Rainscreens are generally cost effective, lightweight, and easy to install, maintain and replace. Most system cladding panels are secured by rivets or screws for code compliance, while some apply fewer rivets or screws by applying their own weight (gravity support). They can be used on new build and refurbishment projects.

The term "cladding" refers to components that are attached to the primary structure of a building to form a non-structural, external surface, either direct or via a supporting and levelling grid of rails or battens often referred to as the façade cladding sub-structure. This is different from buildings where the external surfaces are formed by structural elements, such as masonry walls, or applied cladding such as render or brick-slips.

The main function of the cladding is to protect the building body from climate stresses and mechanical damage. It is common to use a frame of load-carrying metal rails or wood battens to carry the cladding onto the building structure. The plurality of battens, when cross-laid in vertical and horizontal direction one over another, create an air cavity between the cladding and the building structure that allow venting, draining and pressure equalisation (Rainscreen). In a wall with Rainscreen, the cladding acts as a rain shield. Water penetrating the cladding is drained down and the cavity dries out due to air circulation within it. Between the grid of rails or battens and the insulating wall is a semi-open membrane commonly referred to as windbreaker.

Drained and ventilated Rainscreen cladding systems may allow any penetration of moisture to drain inside cavity, evaporate or vented back to the outside. It must allow air in the cavity to be pressurised to the same pressure as caused by wind-gust hitting the cladding. With no pressure difference across cladding, a Rainscreen minimise water penetration into cavity via joints. It also prevents water from being forced through the windbreaker.

Rainscreen cladding or façade cladding can be fabricated from metal sheeting such as aluminium, stainless steel, zinc, copper and so on, or can be formed from metal composites materials. Other materials such as terracotta, brick slips, stone, timber and so on are also used. The use of timber and wooden panels gets increasing popularity globally.

The ventilated façade offers great design freedom and versatility. The selection of suitable fastening solutions is therefore diverse. Rainscreens must be securely anchored to the load-bearing building structure (building structure). The fixing parts ensure all system components, such as insulation, substructure and façade cladding are joined in a lasting and secure way.

A well-known element are battens which carries the load of the façade cladding onto the building structure and provides the air cavity between the façade cladding and the building body. Battens are most commonly a strip of solid material of wood, but can also be of plastic, metal, fiberglass, or other composites. The strip of solid material may be attached to the building structure in vertical and horizontal direction on top of each other to provide a grid of load bearing structure having two vertical planes established by respective vertical and horizontal battens. The grid structure provides the air cavity for ventilation and drainage, and cross-laid battens provide venting and draining of cavity by two parallel two-dimensional planes.

The criss-crossing of battens provide support for fastening the façade cladding and provides the air cavity (gap) for drainage and ventilation. Ventilation openings are made at the bottom and top of the wall so air can naturally rise through the cavity. Building structure penetrations including windows and doors require special care to maintain the ventilation. In a pressure-equalized system, the ventilation openings must be sized to allow air pressure equalization across the cladding. The size depends on volume of enclosed cavity, air tightness of cladding and opening dimensions.

The Rainscreen keep out the rain, and the inner layer (building structure) to provide thermal insulation, prevents excessive air leakage and acts as wind damper. The Rainscreen breaths like a skin while the inner layer reduces energy losses. The structural frame of the building is kept dry, as water do not reach it or the thermal insulation.

However, the drawback of Rainscreens (rear-ventilated facades) is that the air cavity act as a chimney (stack-effect) during fire. Attention is therefore paid to fire protection in such types of construction. Different solutions to mitigate the chimney effect have been proposed and are prescribed by codes world-wide.

Publication <CIT> discloses a fire spread prevention structure comprising a fire spread prevention material for preventing the propagation of flames. In the outer wall ventilation structure of the building, when a fire heat is received, the supply of fresh air is cut off by the volume expansion of the fire spread prevention material to suppress the chimney effect. The structure is a longitudinal structure comprising ventilation openings and the fire spread preventing material to close off the openings in the event of a fire. The longitudinal structure is adapted to be mounted in an air cavity between cladding and inner wall structure.

Cavity barriers resembling <CIT> make up one of the three most common categories on the market. The other and most widespread common cavity barrier category do not have a steel profile and the expanding material in fire is fixed to one side of the cavity, leaving rest of cavity open. The most recent category is mesh encapsulated cavity barriers which block instant flame attack and retain expanded material inside the encapsulated volume.

Publication <CIT> discloses an interior uninsulated drywall comprising passage for air to the attic of a building structure to remove moisture, or hot air from inside the building structure. A fire spread prevention arrangement is located in the internal wall air transfer openings for preventing flames to spread from one floor to another inside the building. The fire prevention arrangement comprises top and bottom plates on studs with air transfer openings covered with a flame-proof net-like body which has the function of ensuring wall ventilation during non-fire, and to prevent fire from passing through the wall ventilation passage when fire spreads. The drawback of these systems is that they are added to the sub-structure and must be tailor-fitted to rails and studs.

In terms of facade fire protection, the drawback of the system described in publication <CIT> is that the fire safety is designed for interior walls of the building structure, i.e. inside of the insulating external wall. The system requires modification of the full size top and bottom plates of the drywalls. The drywall sheathing itself is not fire resistance rated. A fire can still spread in the air cavity in the exterior façade cladding, i.e., chimney effect, in the event of exterior fire spread. The timber construction elements of the wall frame structure of require major modifications of the interior walls of the building and needs to be pre-made during setup of the new building to obtain fire protection performance. The system modifies the load-bearing plates or studs of room compartmentation. Another drawback is that the internal wall structure may reduce the inside living area and are therefore not practical or economical.

Publication <CIT> discloses a façade comprising a non-flammable, thermally insulating layer, an understructure, and a ventilated façade cladding of panels. The understructure is interrupt by horizontal vertical spaced fire stop profiles with rear ventilation. Fire protection strips made of a material that expands when exposed to heat are installed vertically or at an angle to the spaced fire stop profiles.

Publication <CIT> discloses a fire protection system for façade with back ventilation. The system comprises profile rails arranged between the building walls and the façade cladding. The rails have a U-shape cross section with their legs parallel to the façade cladding. The system comprises fire stopper strips of materials that expand during heat to seal off the ventilation zones. The strips may comprise an intumescent carrier bonded to a thermoplastic matrix.

Publication <CIT> discloses a fire protection device for a rainscreen of a building for dividing a cavity between a façade and the rainscreen in the event of fire, in order to create a plurality of fire protection compartments.

The above-mentioned prior art solutions may provide fire protection in combination with adequate ventilation and drainage of the cavity, but they are systems that require additional fire protection components to be installed, or they typically require complicated structural changes or upgrade of building structures. Manufacturer-specific helping hand-brackets are common.

Moreover, the construction of these prior art fire barriers is complicated and expensive. The reliability of installing correctly is proven poor, as multiple decisions and awkward detailing are left to installers on site. Sub-structures are known for multiple failure modes like being installed wrong, or in a wrong location, or upside down, or creating gaps at irregular joints. The object of the present invention is to prevent fire from spreading rapidly from exterior to interior, or interior to exterior, or between fire compartments via the façade rainscreen and its sub-structure.

Another object of the present invention is to provide a ventilated building façade system that has ventilation and drainage properties in addition to fire protection and which can be achieved with a cost-effective and simple configuration that increase fire protection performance and the level of fail-safety. In addition, it shall allow module pre-fabrication.

The present invention is related to a ventilated and fire-resistant sub-structure of a façade system.

The façade system comprising cladding and the sub-structure of one or more battens attached to the building load-bearing structure to support the cladding onto the building structure and to create a cavity between the load-bearing structure and the cladding.

The one or more battens is attached at one longitudinal side to a surface of the building structure, and opposite longitudinal side to the façade cladding, and wherein the one or more battens comprises a ventilating and fire-resistant batten comprising one or more through openings, and one or more cavity fire barriers arranged in or adjacent the one or more through openings.

The ventilating and fire-resistant batten allows air to pass through the one or more through openings into and/or out of the cavity and adapted to block for air passage and/or fire penetration through the one or more openings when exposed to fire.

The sub-structure replaces both the traditional criss-cross furring system and cavity fire barriers.

The ventilated façade system may also be referred to as a Rainscreen.

The present invention is related to the sub-structure to support the cladding of a fire-resistant Rainscreen.

The term "batten" is also referred to as furring (furring strips) and are strips of wood or other material to level or raise surfaces of another material to prevent dampness, to make space for ventilation, and/or to carry façade cladding onto a building structure.

The one or more battens make up a single sub-structure or make up different sub-structures of different properties. However, the one or more battens is at least a ventilating and fire-resistant batten comprising one or more through openings and a cavity fire barrier located within or adjacent to the one or more air transfer openings.

The one or more battens may be uniform elements that is hand-held and easily mounted without helping hand-brackets and risk of fixing them in a wrong way, in wrong location or upside down or creating gaps to fire.

The one or more through openings may be arranged through a cross-section of the one or more batten. The through opening or openings may be perpendicular to the longitudinal direction of the batten or it may be in any angle relative to the longitudinal direction. The through opening may also be referred to as an air transfer opening.

The term cross-section is directed to a section perpendicular to the longitudinal direction of the longitudinal batten.

The one or more battens may have an inclined upper surface directed towards the one or more through openings such that liquid is directed towards and through the one or more through openings. The lower surface may have an equivalent inclined surface providing a drip edge preferably in the centre of the downward facing air transfer opening.

The one or more through openings in the ventilating and fire-resistant batten provides a flow control arrangement similar to a reactive slit valve. The arrangement controls the flow of air in the cavity by allowing air to naturally flow during normal operation/state, which is in everyday use, but in the event of a fire and when exposed to heat, the "valve" reacts by closing the air flow and blocks the fire. The one or more cavity barriers may therefore comprise a heat reaction device adapted to react by changing physical property, such as reactive materials or phase-changing materials, when exposed to heat. In addition, the one or more cavity fire barriers comprises a plurality of perforations and/or mesh structure to allow the ventilation and drainage through the barriers.

The one or more battens that makes up the sub-structure may comprise one or more elements of solid material of wood, plastic, metal, composites, or any combination thereof. The one or more battens may comprise a traditional batten of solid material, and any combination of traditional battens and ventilating and fire-resistant battens.

The ventilating and fire-resistant batten may constitute one single longitudinal element, and the one or more through openings are provided in any angle through a cross-section of the one single longitudinal element. The term "one single longitudinal element" denotes a single element that is cut out, moulded or casted in one piece. The one single element may be any one of a: wood element, plastic element, metal element or composite element, and the through opening may be created by casting or moulding, or drilling, carving, cutting through the body of the longitudinal element. The one or more through openings may be circular, oval, rectangular, square shaped or any combination thereof.

The one single longitudinal element may further comprise recesses, cut-ins, slits, slots, gripping means, holding means, or supports for fixing the ventilating barriers or retain them in position in or adjacent the openings. The ventilating fire barrier may be removably connected to the batten and may extend continuously beyond the through opening in the longitudinal direction of the batten.

The ventilating and fire-resistant batten may comprise a first longitudinal element, a second longitudinal element and a spacer element arranged between them so that the through openings are provided between the first and second elements. The through openings may also be referred to as a space or a gap. Thus, the one or more through openings are one or more through-holes, spaces, gaps or volumes provided between the first and second longitudinal element. The ventilating and fire-resistant batten may further comprise one or more cavity fire barriers arranged between the first and second longitudinal elements such that it allows air to pass through the one or more spaces and block for air passage or fire penetration through the one or more spaces when exposed to heat, such as in the event of fire.

The one or more spacer elements may be any one of a: spacer screw, block, wedge, bracket or any combination thereof. The one or more spacer elements may be made from any materials such as: wood, metal, plastic, composite, or any combination thereof.

The one or more spacer elements may be located at a centre between the first and second longitudinal elements, or it may be located at any side, or any combination thereof.

The space between the first and second elements may be a longitudinal space having a longitudinal opening defined by edges of the first and second longitudinal elements, and wherein the one or more ventilating fire barriers may be arranged in the opening or adjacent the opening such that it may block the longitudinal opening when exposed to heat. The one or more longitudinal space has openings at either longitudinal side for air and moisture passage in either direction through said space.

The first and second longitudinal elements may be of same shape and same thickness, or they may have different shapes and different thickness. They may have a rectangular cross-section with longitudinal sides with small surfaces and wide surfaces, wherein the first and second longitudinal elements may be placed in parallel with the wide faces facing each other and with the spacer elements located in between.

The longitudinal space is defined by the size of the one or more spacer elements, such that smaller and larger spaces can be used based on requirements for ventilation, drainage, pressure control, or fire safety.

The one or more spacer elements may be arranged between the first and second longitudinal elements such that it allows the one or more cavity fire barriers to extend past the one or more spacer elements in the longitudinal direction of the one or more longitudinal spaces, to provide a "seamless" and continuous barrier. This means that the one or more spacer elements may be shorter than a length (depth) of the one or more through openings, providing space for attaching the one or more cavity barriers, and that the one or more cavity barriers may be one longitudinal barrier extending continuously beyond or past the one or more spacer elements.

The one or more spacer elements may be arranged along a longitudinal side of the first and second longitudinal elements, or the one or more spacer elements may be arranged along a longitudinal short side. The spacer element may comprise a collar or an edge extending into the opening between the first and second longitudinal elements to support the first and second longitudinal elements and to create the space between said elements.

The spacer element may be a bracket, or the spacer element may be a screw or a nail with two collars arranged with a distance between each other along the body of the screw or nail, the distance provides the space between the first and second longitudinal elements.

The one or more cavity fire barriers may comprise a heat reactive device adapted to react by changing physical property when exposed to heat from the fire such that it becomes gas tight.

The one or more cavity fire barriers may comprise a mesh structure with intumescent. Such products are readily available on the market. Preferred performances in façades are fire resistance during the open state, expanding graphite and encapsulating mesh of a fixed volume for optimized expanded material compaction and no loss of material by fall out.

The one or more cavity fire barriers may be a removeable device adapted to be inserted into, or extracted from, the one of more through opening.

The one or more cavity fire barriers may be flexible such that it can be easily shaped and be squeezed into the one or more through openings. The one or more battens may comprise a slot or recess for receiving the one or more cavity fire barriers. The one or more cavity barriers may be fastened by nails, screws or brackets and may be removably attached to the one or more battens. The one or more cavity fire barriers may be easy to shape and may be cut to fit smaller sections.

The one or more cavity fire barriers is a passive fire-resistant device, which preferably instantly can prevent fire from spreading via the air passage (through openings) to other areas or spaces. A preferred embodiment of the cavity fire barrier is to prevent fire spreading by heat convection, by heat conduction and by heat radiation during the entire fire resistance period.

The ventilating and firesafe batten according to the present invention provide loadbearing and/or support of façade cladding, ventilation, drainage, and fire resistance in one unit. Prior art battens are solid, and they need to be cross-laid one over another to create the cavity and make the rising air stream bouncing in slalom-mode as the cavity spans in two vertical planes. This leads to the ventilating fire barriers being installed separately, adding manhours and becoming sensitive to poor workmanship.

The through openings, gap or space, of the batten according to the present invention, provides the acquired space for ventilation and drainage, and the batten is versatile in that it can be used with or without the cavity fire barrier. Thus, the ventilating batten may be turned into a ventilating and fire blocking or fire-resistant batten by inserting or attaching the cavity barrier into or adjacent the through openings. Likewise, the ventilating and fire-resistant batten may be made without fire resistance by removing the cavity fire barrier. This operation may easily be done at site during set-up, and it may also save cost by reducing waste and downtime. In addition, it is easy to visually or with camera, verify that each batten is correctly mounted, and each cavity fire compartment correctly established before the façade cladding is mounted.

The ventilating and fire-resistant batten may be assembled having symmetric cross-section. The symmetric cross-section may be provided by a spacer element placed at centre and with a fire barrier arranged at either side, or the fire barrier may be arranged at the centre and the spacer elements at either side. The symmetric batten is easy to mount either way, up or down, in or out, and by such avoid mis-mounting.

The one or more battens may be attached to the building structure in any vertical and/or horizontal direction. By the one or more battens all having same width they are in one vertical plane in parallel to the building structure plane and always spanning tight across cavity.

The cavity fire compartmentation is established by the sub-structure which sub-divides the cavity to align with the room fire compartmentation of the building interior. In some cases of large compartment areas added battens of solid materials may be applied to support cladding where window framing is not sufficient, although not part of the compartmentation. Compartmentation is made up of the fire resistance rated cladding and sub-structure battens only.

The one or more battens according to the present invention are easy to fabricate and to setup and its simple construction avoids mis-mounting. In addition, its easy construction allows it to be easy cut in smaller sections to fit mounting, and for easy replacement in case of repair or damage. The ventilating batten according to the present invention is practically maintenance-free.

The ventilating and fire-resistant batten has ventilating and fire-resisting properties in one single unit. The one or more battens may have same width such that a depth of the cavity is defined by the width from the one longitudinal side to the opposite longitudinal side of the one or more battens. Thus, the one or more battens one lies in one vertical plane in parallel to the building structure plane.

The one or more battens may further comprise at least any one of a:.

The ventilating batten may have same dimensions and configuration as the ventilating and fire-resistant batten without the one or more cavity fire barriers. The ventilating batten may constitute one single longitudinal element with trough holes for ventilation, or it may comprise first and second longitudinal elements with a spacer element.

The present invention may also be directed to a ventilating batten comprising a through opening for drainage and ventilation and wherein the ventilating batten may be transformed to a ventilated and fire resisting batten by adding a cavity fire barrier at or adjacent the through opening, and vice versa. The transformation may be performed on site when the battens are already fixed to the wall structure. The ventilating batten may constitute one longitudinal element with trough openings, or it may comprise two elements with spacer elements, according to the embodiments described above.

The solid batten may have the same dimensions as the ventilating and fire-resistant batten but are without the through openings and without the one or more ventilating fire barriers. The solid batten may be one single longitudinal element.

The battens may be made from any materials such as: wood, metal, composite, rock wool, concrete, or combination thereof, as long as they provide the required time of fire resistance. Typical Rainscreen cavity barriers are <NUM> rated despite cladding being capable of less, typically <NUM>-<NUM>. The present invention lends itself as a homogenous fire rated exterior building envelope, rated at <NUM> or <NUM> or more and having cavity fire compartmentation as well as ventilating compartmentation either covering the same cavity volumes or having independent layouts.

A defined area in the cavity may be enclosed by a combination of solid battens, ventilating battens and/or ventilating and fire-resistant battens (the one or more battens) to form a cavity fire compartment within the cavity having corresponding fire resistance time in case of fire.

A cavity fire compartment may be created in the cavity by a plurality of the one or more battens arranged at a perimeter of the cavity fire compartment. The cavity fire compartment is a space or group of spaces within the cavity between the façade cladding and the building structure with fire resistant properties.

The cavity fire compartment defined by the one or more battens may comprise; sides, top and bottom, and wherein the ventilating and fire-resistant battens are arranged at any sides, top and/or bottom consistent with room fire compartmentation layout or layout specified by project specific fire strategy.

The cavity may be sub-divided into one or more cavity fire compartments and wherein the cavity comprises a continuous number of said cavity fire compartments. Meaning that several cavity fire compartments may be arranged adjacent to each other in the cavity. The several cavity fire compartments being arranged with ventilation and/or fire resistance between each other, or they may not, depending on the project specific fire strategy.

The façade cladding may be made from any materials suitable for use as a building façade. The materials may be, but not limited to any one of a: wood panel, PV panel, sandwich panel, fibre cement plates, calcium silicate panel, stone, slate, brick, ceramic element and brick tie, or any combination thereof. They can all be easily attached to the ventilating and fire resistance rated batten (alone or in combination with other battens) which in turn are fastened to timber construction or to other type of load-bearing construction of the building structure.

To exploit the fire resistance performance of the present invention the cladding can be rated equal to the one by cavity battens, i.e., the cavity compartment resistance to exterior fires.

The façade cladding may comprise a plurality of boards interconnected, and wherein each board comprises one or more fire expanding materials in connection joints between the plurality of boards, such that the board obtains a same fire protecting property as the cavity fire compartment.

Cavity fire compartmentation is similar to building fire compartmentation, except the cavity compartments become "flat volumes" rather than "cubic" as interior room compartments. To fully exploit the present invention, the cavity compartments align with the profile of interior compartments. The cladding system thus represents the fourth wall of room compartments, so the non-fire resistance rated windbreaker, sheathing, insulation, and room cladding, actually become content of the combined room + cavity compartment. The present invention thus allows the listed content to be combustible and prevent fire spread inside out, outside in and between compartments above, under or to the sides. This is not possible by code compliant façade systems, as there is no equal fire resistance rating of the full enclosure of cavity compartment.

When a climate wall (wall between room and cavity) has no rated burn-through time, the cavity fire compartment is considered including those areas. This means that in case of fire, the fire compartment may burn out during the time for which it is rated, without spreading the fire to façade or to neighbouring compartments (side, above or below). This means also that surface requirements for rear cladding, battens, and windbreakers, all have the same requirements for ignition- and fire spread properties as for interior of room fire compartment (less stringent than facade surface requirements).

For example, if a horizontal batten has burn-through time of <NUM>. and cladding <NUM>; then an interior fire may burn out through the cladding in <NUM>, and in again into another compartment through the cladding in another <NUM>, the total burn time is <NUM>, which is also the fire compartment burn-through time rating. Burn-through time for an exterior fire spreading to the interior through the cladding is <NUM>.

The present invention describes a self-supporting and easy fixed fire resistance rated Rainscreen, without use of fire-retardant additives, that prevents fire from spreading rapidly from exterior to interior, or inside to outside, or between fire compartments. The system comprises a suspension system of structural battens without fire-retardant additives.

The suspension system may constitute a one-plane system without the traditional cross-laying of the battens. The system may comprise a plurality of battens having same outer dimension but may have different properties such as solid (airtight) or ventilated with or without fire resistance rating. The fire protection designer or contractor may consider where to establish cavity fire compartments and how each compartment can be effectively isolated in the event of fire.

The ventilating and fire-resistant batten according to the present invention comprises fully integrated reactive slit valves that are fully passive between an open position (during normal use) and a closed position in the event of a fire. In the open position, during normal and everyday use, the valve provides ventilation, drainage, and pressure equalization to the Rainscreen. Depending on type of ventilating cavity fire barrier (valve) these may instantly block flame attacks in normal mode (open state), i.e., the preferred performance in facades. After seconds ventilating barrier closes by expanded material to prevent further fire spread.

The rear ventilated building system of the present invention prevents two-sided fire exposure to cladding, by preventing the fire to propagate into the air cavity. The fire on wood cladding surface self-extinguishes when fire source burns out or extinguish and prevents hidden fire, so firefighting can take place on the outside of the building structure where the fire is active.

A rear ventilated building system of the present invention allows cavity fire compartments in the cavity to become part of a room fire compartment it corresponds to within the building. Hence, fire requirements for materials in climate walls and air cavity/cavity fire compartments will then be waived. Hidden fire spread in multi-level air cavities (greatest challenge in case of fire in facades today) may be prevented and fire stop around windows may not be needed.

Due to uncompromised sub-division of cavity, it is not necessary to use firestopping around windows within the cavity fire compartment, thus reducing overall cost of the building.

Eave's construction may be reinforced with increased panel thickness of wood to withstand the severe fire exposure, and by wooden blocks/batten in corners and other connections to keep the same burn-through time as the fire cell. Ventilating and fire-resistant rated battens may be provided in the soffits of eaves.

The system according to the present invention protects people in building from exterior fire by fire rated compartmentation, regardless of fire resistance in the climate wall. This protects persons in buildings from smoke as well, be it from exterior fire or interior fire breaking out.

The present invention may be related to a method of constructing a cavity fire compartment in a cavity located between a building structure and its façade cladding.

The step of attaching the façade cladding onto the one or more battens may also be performed before the step of mounting the one or more cavity fire barriers.

The flexibility of the system allows for easy change of layout or construction of fire cavity compartments, in that the compartments can be opened or closed by the one or more cavity fire barriers.

The present invention may also be related to a method of manufacturing a prefabricated ventilating and fire resistance rated batten, wherein the method comprises the step of:.

The method further comprises the step of attaching the one or more cavity fire barriers after the step of attaching the second longitudinal element to the one or more spacer elements, step iii) after step iv).

The present invention may also be related to a method of constructing a Rainscreen comprising a ventilated and fire resistance rated air cavity arranged between an inner and outer structure of a building. The method comprises the step of:.

Further objects, structural embodiments and advantages of the present invention will be seen clearly from the following detailed description, the attached figures, and the claims below.

The invention will now be described with reference to the attached figures, wherein:.

In the following, exemplified embodiments of the invention will be discussed in detail with reference to the appended figures. It should be understood, however, that the figures are not intended to limit the invention to the subject-matter depicted in the figures.

<FIG> shows a ventilated façade cladding system <NUM> according to the present invention. The system comprises a building structure <NUM>, a façade cladding <NUM>, and a plurality of battens <NUM> attached to the building structure <NUM>. The plurality of battens may be a combination of solid batten <NUM> (with no ventilating openings), ventilating battens <NUM> and ventilating and fire-resistant battens <NUM>. The plurality of battens are attached to the building structure <NUM> and adapted to carry the façade cladding <NUM> onto the building structure <NUM>. This means that the façade cladding <NUM> is attached to the plurality of battens <NUM> and that its weight is entirely carried or supported by the plurality of battens <NUM>.

The façade cladding <NUM>, the plurality of battens <NUM> and the building structure <NUM>, creates a cavity <NUM> located between the building structure <NUM> and the façade cladding <NUM>. As shown in <FIG>, the depth of the cavity <NUM> is defined by a depth of the battens <NUM> which is the distance between the inner surface of the batten attached to the building structure, and outer surface of the batten attached to the rear of cladding. The plurality of battens <NUM> all have same depth such that the outer surface for attaching the façade cladding <NUM> is in one vertical plane.

As shown in <FIG>, the plurality of battens <NUM> are attached at one longitudinal side (inner surface) to a surface of the building structure <NUM>, and opposite longitudinal side (outer surface) to the façade cladding <NUM>. The vertical batten <NUM>, is a solid batten <NUM> arranged such that it prevents air to move between vertical sections of the cavity <NUM>. The horizontal battens <NUM> may be ventilating battens <NUM> and/or ventilating and fire-resistant battens <NUM>, consistent with room fire compartmentation layout or layout specified by project specific fire strategy.

<FIG> shows the system from above and including a window opening in the ventilated façade cladding system <NUM>. The vertical battens <NUM> are solid battens <NUM> which is also framing the window opening. Horizontal battens <NUM> may be ventilating battens <NUM> and/or ventilating and fire-resistant battens <NUM>. According to room fire compartmentation layout, the horizontal battens <NUM> around window opening may be a ventilating and fire-resistant batten <NUM>, to "close off" the window opening in the event of a fire. If a window is within the perimeter of a cavity fire compartment the framing may not require fire-resistant battens <NUM> nor any ventilating battens <NUM>.

The horizontal battens <NUM> may be a ventilating batten <NUM> comprising a first and second longitudinal elements <NUM>,<NUM>, a spacer element <NUM> located between the first and second elements <NUM>,<NUM> to provide an opening <NUM> (gap/space) between the first and second elements <NUM>,<NUM>.

The ventilated batten <NUM> may be transformed to a ventilating and fire-resistant batten <NUM> by adding the cavity fire barrier <NUM> into the ventilating through openings <NUM> of the ventilating batten <NUM>. Likewise, the ventilating and fire-resistant batten <NUM> may be transformed to a ventilating batten <NUM> by removing the cavity fire barrier <NUM>. This system provides easy set up offers design freedom and versatility. In addition, the system <NUM> substantially prevents flawed or poor installation during construction since cavity fire compartmentation can be easily monitored, adjusted, or changed at any time during on-site construction.

<FIG> shows the system <NUM> from below. The façade cladding <NUM> comprises a plurality of boards <NUM> interconnected, and wherein each board <NUM> comprises one or more fire expanding materials at joints <NUM> between the plurality of boards <NUM>, such that the boards <NUM> obtain the same fire resistance rating as the cavity fire compartment <NUM>. The end joints of each board <NUM> may comprise a longitudinal slot <NUM> containing the fire expanding material. In the event of fire, the fire expanding material will react to the heat and cause the material to expand and thereby fire sealing the longitudinal gaps between the boards <NUM>. This allows the façade cladding <NUM> to have the same fire-resistance rating as the cavity fire compartment <NUM>.

<FIG>)-c) shows different ventilating battens <NUM> each made from one single longitudinal element. The one single longitudinal element comprises one or more through openings (holes) <NUM> to provide ventilation through the batten <NUM>. The through openings <NUM> may be in any angle through a cross-section of the longitudinal batten <NUM>. The figures show through openings <NUM> provided perpendicular to the longitudinal direction of the longitudinal batten <NUM>.

The one single longitudinal element may be any one of a: wood element, plastic element, metal element or composite element, and the through opening <NUM> may be created by casting or moulding, or drilling, carving, cutting through the body of the one longitudinal element. The one or more through openings <NUM> may be circular, oval, rectangular, square shaped or any combination thereof. The through openings <NUM> may constitute a plurality of holes as shown in <FIG>), or they may be one or more through holes/openings <NUM> having circular edges or angled corners shown in respective <FIG>). The ventilating batten <NUM> in <FIG>)-c) may be transformed into a ventilating and fire-resistant batten <NUM> by adding the cavity fire barriers <NUM> into and/or adjacent the through openings <NUM> (not shown).

<FIG> shows, as an embodiment, a connection point between a vertical batten <NUM> and a horizontal batten <NUM>, wherein the horizontal batten <NUM> is a ventilating and fire-resistant batten <NUM> and the vertical batten <NUM> is a ventilating batten <NUM> or ventilating and fire-resistant batten <NUM> (the cavity fire barrier not shown).

The batten <NUM> comprises a first longitudinal element <NUM>, a second longitudinal element <NUM> and a spacer element <NUM> arranged between them so that through openings <NUM> are provided between the first and second elements <NUM>,<NUM>. The openings <NUM> may also be referred to as spaces or gaps. Thus, the one or more through openings <NUM> are one or more through-holes, gaps, spaces, or volumes provided between the first and second longitudinal element <NUM>,<NUM>. The size or length of the spacer elements <NUM> defines the size of the gap, space and volume of the through openings <NUM>.

The one or more spacer elements <NUM> may be any one of a: spacer screw, block, wedge, bracket or any combination thereof. The one or more spacer elements <NUM> may be made from any materials such as: wood, metal, plastic, compressed stone wool, composite, or any combination thereof. <FIG> shows that the spacer elements <NUM> may be wooden blocks having a height which is less than the height of the through opening <NUM> to provide enough space in the gap for the cavity fire barrier <NUM>.

A ventilating batten <NUM> as described above may be transformed into a ventilating and fire-resistant batten <NUM> by adding the cavity fire barrier <NUM>. The cavity fire barrier <NUM> is arranged between the first and second longitudinal elements <NUM>,<NUM> such that it allows air to pass through the one or more opening or spaces <NUM> and block for air passage or fire penetration through the one or more openings or spaces <NUM> when exposed to heat, such as in the event of fire.

To provide a completely sealed cavity fire compartment <NUM> at a joint between a vertical batten <NUM> and a horizontal batten <NUM>, the one or both two battens <NUM> may be a solid batten <NUM>, or at least one is solid batten <NUM> and one is a ventilating and fire-resistant batten <NUM>, or both is a ventilating and fire-resistant batten <NUM>. In the latter, the cavity fire barriers <NUM> of the vertical battens <NUM> meets the cavity barrier <NUM> of the horizontal batten <NUM> to provide a complete seal at the joints. The vertical batten <NUM> may be joined to the horizontal batten and interconnected at any location along the horizontal batten <NUM>.

<FIG> shows a prefabricated ventilating and fire-resistant batten <NUM> according to the present invention. The prefabricated batten <NUM> may be provided as a ventilating batten <NUM>, or complete as a ventilating and fire-resistant batten <NUM>. The battens <NUM>, <NUM> are easy to fabricate and to set up and its simple construction avoids faulty installation. In addition, the construction allows it to be easily cut into smaller sections to fit mounting, and for easy replacement in case of repair or damage. The batten <NUM>, <NUM> according to the present invention is practically maintenance-free.

The ventilating and/or the ventilating and fire-resistant batten <NUM>, <NUM> may also be assembled on site. They can be delivered in one piece (one single longitudinal element) provided with openings <NUM> (as shown in <FIG>)-c)), or they may be delivered on site as components as shown in <FIG>.

The method of assembling and installing the ventilating batten <NUM> at sight may comprise the steps of:.

In the case a ventilating and fire-resistant batten <NUM> is required the method includes these steps:
iv) inserting and fix one or more cavity fire barriers <NUM> into the one or more longitudinal spaces or openings <NUM>.

<FIG> show different cross-sections of ventilating and fire-resistant battens <NUM> or a view in any direction from a cross-section of the longitudinal ventilating and fire-resistant batten <NUM>. The cavity fire barrier <NUM> (may also be referred to as a ventilating and fire blocking fire barrier) may have different shapes and located at different positions in the gap, space, opening <NUM>. It may have oval shape or circular or a material strip that can be shaped and fitted into the gap, space, opening <NUM> to provide a tight seal in any position inside and/or adjacent the gap <NUM>. <FIG> shows two cavity fire barriers <NUM> arranged on either side of the spacer element <NUM> to provide a symmetric batten <NUM> that can be used in any of the two directions to prevent faulty installation. The cavity fire barrier <NUM> allows water to be drained through the barrier <NUM> and allows air to pass through the barrier <NUM> and operate as a reactive vent in case of a fire.

<FIG> shows a ventilating and fire-resistant batten <NUM> according to an embodiment of the present invention during situations of ventilating a), draining b) and fire blocking c).

<FIG> shows the ventilating and fire-resistant batten <NUM> in the assembled state comprising first and second longitudinal elements <NUM>,<NUM> and the spacer elements <NUM> in form of a sleeve of a spacer screw <NUM>. The spacer screw <NUM> comprises a screw head for fastening the sleeve between the first and second longitudinal elements <NUM>,<NUM>, and such that the space, gap, opening <NUM> is provided between said longitudinal elements <NUM>,<NUM>. The spacer screw <NUM> may comprise two screw heads, with male and female threads, located on opposite sides of the batten for tightening the sleeve between first and second longitudinal elements <NUM>,<NUM>.

The ventilating and fire-resistant batten <NUM> may be a prefabricated unit such that it is ready to use, or it can be assembled at site using the spacer screws <NUM>. The cavity fire barrier <NUM> is located in the gap, space, opening <NUM>, and may be removably mounted into the said gap, space, opening <NUM>.

<FIG> show that under normal (everyday use), the batten <NUM>,<NUM> provides necessary drainage for water down in the vertical direction. The upper surface of the batten <NUM> may have a bevel cut, thus providing an inclination towards the through opening <NUM> for leading water through the opening 11in vertical direction. At the bottom, the batten may comprise the same inclination (may be parallel to the one above) providing a centred drip edge so droplets fall onto next barrier and do not wet cavity surfaces. The cavity fire barrier <NUM> also provides necessary ventilation in that it allows air to circulate through the opening <NUM> in any direction.

The one or more cavity fire barriers <NUM> may comprise a heat reactive device adapted to react by changing physical or chemical properties when exposed to heat from the fire such that it becomes fire sealed. <FIG> shows that in the event of fire, the heat reactive device reacts similar to a reactive slit valve. The arrangement controls the flow of air in the cavity by allowing air to naturally flow during its open state, which is in everyday use, but in the event of a fire and when exposed to heat, the "valve" reacts by blocking the fire and closing the air flow. Thus, the defined cavity fire compartment <NUM>, will be sealed from the fire to avoid and resist the fire from propagating into the compartment <NUM> and to resist fire spread to adjacent compartments.

The one or more cavity fire barriers <NUM> may comprise a mesh structure with intumescent. Such products are readily available on the market. Preferred performance in façades are fire resistance during the open state, expanding graphite and encapsulating mesh of a fixed volume for optimized expanded material compaction and no loss of material by fall out.

<FIG> shows a cross sectional view from a side of the ventilated façade cladding system <NUM> (or Rainscreen) according to an embodiment of the present invention. The system comprises a building structure <NUM> (or a load-bearing wall <NUM>) and a draining and ventilating and fire-resistant batten <NUM> attached to the building structure <NUM> for carrying a façade cladding <NUM> at a distance defined by the batten <NUM> from the building structure, and such that a cavity <NUM> is provided between the building structure <NUM> and the façade cladding <NUM>. The entire weight of the façade cladding <NUM> is supported by the plurality of battens <NUM> (not shown), which according to the present invention may be any one of a: solid batten <NUM>, draining and ventilating batten <NUM> or draining and ventilating and fire-resistant batten <NUM>.

The <FIG> shows a lower section of the Rainscreen where the lowermost batten <NUM> is a ventilating and fire-resistant batten <NUM> arranged for providing the necessary ventilation, draining, and fire-retardant properties. The batten <NUM> is one of a plurality of battens <NUM> that together defines the perimeter of a cavity fire compartment <NUM> within the cavity <NUM>.

<FIG> shows the system in the case of an exterior fire located on the ground where the cavity fire barrier <NUM> is activated due to the heat from the fire and such that the ventilation though the opening <NUM> is closed-off, to provide fire blocking and prevent the fire to propagate into the cavity fire compartment <NUM>.

<FIG> shows another fire ventilated façade cladding system <NUM> according to the present invention from a side view of a building comprising two floors. A defined area in the cavity <NUM> may be enclosed by a combination of solid battens (not shown), draining and ventilating battens <NUM> and/or draining and ventilating and fire-resistant battens <NUM> to form a cavity fire compartment <NUM> within the cavity <NUM> having corresponding fire resistance time in case of fire.

The cavity fire compartment <NUM> is created by the ventilating and fire-resistant batten <NUM> arranged at the top and bottom of the cavity fire compartment <NUM>. Located between the top and bottom ventilating and fire-resistant battens <NUM>, are two ventilating battens <NUM>. According to the present invention, different extent of the cavity fire compartment <NUM> can be created by transforming the ventilating batten <NUM> into a ventilating and fire-resistant batten <NUM>, or vice versa.

The cavity <NUM> may thus be sub-divided into one or more cavity fire compartments <NUM> and wherein the cavity <NUM> may comprise a continuous number of cavity fire compartments <NUM>. Each cavity fire compartment <NUM> may be constructed based on room fire compartmentation layout or layout specified by project specific fire strategy.

<FIG> shows a front view of a building structure <NUM> comprising a plurality of battens <NUM>, but without the façade cladding <NUM> attached. The battens <NUM> may be any combination of solid batten <NUM>, drained and ventilating batten <NUM> and/or drained and ventilating and fire-resistant batten <NUM>. A cavity fire compartment <NUM> may be provided by arranging a combination of solid battens <NUM> (no ventilation) and ventilating and fire-resistant battens <NUM>, at the perimeter of the cavity fire compartment <NUM>.

<FIG> shows an embodiment where the vertical battens <NUM> are solid battens <NUM> for closing off different section of the cavity <NUM>. The term "close-off" means that there will be no air allowed to cross the batten <NUM>. Furthermore, a plurality of ventilating battens <NUM> are arranged horizontally for providing ventilation and drainage in the cavity <NUM>. According to the building fire strategy, some of this cavity needs to be fire stopped in the event of fire to avoid the chimney effect. Therefore, the ventilating and fire-resistant batten <NUM> are arranged at the top and bottom of the area to provide a cavity fire compartment <NUM> within the cavity <NUM>. The cavity fire compartment <NUM> comprises solid battens <NUM> at the sides and ventilating and fire-resistant batten <NUM> at top and bottom. The ventilating and fire-resistant batten <NUM> may also be arranged around window openings together with the solid batten <NUM> to close off the cavity fire compartment <NUM> around the window if required by code or building fire strategy.

<FIG> illustrated the flexibility of the system <NUM> in that the cavity fire compartment <NUM> within the cavity <NUM> can be designed according to building physics and fire protection. The present invention allows the ventilating part of a Rainscreen air cavity <NUM> (cavity ventilating compartment) to extend different from a cavity fire compartment <NUM>. The layouts for venting and fire stopping therefore may be different. Venting compartments may by larger than fire compartments or vice versa. <FIG> shows how the versatile battens <NUM> of types solid <NUM>, venting and draining <NUM> or fire-resistant draining and venting <NUM> can be interconnected and mixed by façade and fire protection designers to fit the specifics of any building regarding fire and building physics.

The system allows great design freedom and versatility in that different areas can be opened to be included in the cavity fire compartment <NUM>, or the cavity fire compartment <NUM> may be reduced by moving or limiting the perimeter of the cavity fire compartment <NUM>. This can be easily done by adding or removing a cavity fire barrier to/from a ventilating batten <NUM>.

<FIG> shows a ventilating and fire-resistant batten <NUM>,<NUM> according to one embodiment of the present invention. The ventilating and fire-resistant batten <NUM>,<NUM> comprises one or more through openings <NUM> (space <NUM>, gap <NUM>) provided between the first longitudinal element <NUM> and the second longitudinal element <NUM>. The through openings <NUM> or space <NUM> is provided by a spacer element <NUM> arranged between or into the through opening <NUM>.

The spacer element <NUM> is a bracket arranged at the longitude short side of the first and second longitudinal elements <NUM>,<NUM> and comprises an edge protruding into the opening or space <NUM>. The two edges of the bracket keep the first and second longitudinal elements <NUM>,<NUM> in a desired distance from each other, thus defining the through opening <NUM>, space <NUM> or gap <NUM>.

The ventilating and fire-resistant batten <NUM>,<NUM> comprises one or more cavity fire barriers <NUM> arranged in or adjacent to the one or more through openings <NUM>, wherein the ventilating and fire-resistant batten allows air to pass through the one or more through openings <NUM> or gap <NUM> and adapted to block for air passage and/or for fire penetration through the one or more openings <NUM> when exposed to fire. The one or more cavity fire barriers <NUM> may comprise a heat reactive material adapted to react by changing physical or chemical properties when exposed to heat from the fire such that it becomes fire sealed. Flame blocking during the open state of vent may feature baffles, labyrinths or mesh designed to quenching gap <NUM>.

The one or more cavity fire barriers <NUM> may comprise an intumescent strip <NUM>, such as shown in <FIG>, or the intumescent may be integrated in the structure of the one or more cavity fire barriers <NUM>.

Claim 1:
A ventilated façade cladding system (<NUM>) comprising:
- a building structure (<NUM>),
- a façade cladding (<NUM>), and
- a sub-structure of one or more battens (<NUM>) are attached to the building structure (<NUM>) to support the façade cladding and to create a cavity (<NUM>) between the building structure (<NUM>) and the façade cladding (<NUM>), the one or more battens (<NUM>) is attached at one longitudinal side to a surface of the building structure (<NUM>), and opposite longitudinal side to the façade cladding (<NUM>),
the one or more battens (<NUM>) comprises a ventilating and fire-resistant batten (<NUM>,<NUM>) comprising:
- one or more through openings (<NUM>), and
- one or more ventilating cavity fire barriers (<NUM>) arranged in or adjacent to the one or more through openings (<NUM>),
wherein the ventilating and fire-resistant batten allows air to pass through the one or more through openings (<NUM>) into and/or out of the cavity (<NUM>) and is adapted to block for air and/or for fire penetration through the one or more openings (<NUM>) when exposed to fire, the ventilating and firesafe batten provide support of façade cladding, ventilation, drainage, and fire resistance in one unit,
characterized in that the one or more ventilating cavity fire barriers (<NUM>) is a removeable device adapted to be inserted into, or extracted from, the one of more through opening (<NUM>).