EP4281626A1

EP4281626A1 - Sealing strip for sealing joints between the surfaces of two adjacent components

Info

Publication number: EP4281626A1
Application number: EP22700475.1A
Authority: EP
Inventors: Stéphanie VAN LINDEN; Nathan VAN DEN BOSSCHE
Original assignee: Universiteit Gent
Current assignee: Universiteit Gent
Priority date: 2021-01-22
Filing date: 2022-01-10
Publication date: 2023-11-29
Also published as: JP2024505170A; WO2022157023A1

Abstract

The present invention relates to a sealing strip for sealing joints between the surfaces of two adjacent components. The sealing strip comprises a main body defining a drainage structure that forms a drainage cavity when provided between the surfaces of the two adjacent components. The drainage structure comprises a top drainage layer having one or more top recesses extending downward in the top surface of the body, wherein each top recess is in fluid communication with a drainage opening in the front surface of the body. Moreover, none of the top recesses are in fluid communication with a drainage opening in the back surface of the body if any. The present invention further relates to a method for sealing joints between the surfaces of two adjacent components.

Description

SEALING STRIP FOR SEALING JOINTS BETWEEN THE SURFACES OF TWO ADJACENT COMPONENTS

Field of the Invention

The present invention relates to a sealing strip for sealing joints between the surfaces of two adjacent components. The present invention further relates to a method for sealing joints between the surfaces of two adjacent components.

Background

During the construction of the exterior walls of buildings as well as during the installation of window frames or facade panels, linear joints are formed. These joints need to accommodate the expansion and contraction of adjacent components and tolerances on the building components and the installation. As these joints are exposed to weather conditions, i.e. rain and wind, they need to be sealed air- and watertight to prevent damage to cladding systems and structural elements, and to prevent cold draughts and/or heat losses.

To effectively and efficiently seal joints between facade elements, several problems need to be solved. First of all, the seal must prevent the transport of rainwater to the interior side of the joint. This can be accomplished either by keeping out the rainwater at the exterior surface of the joint or by draining infiltrated water back to the exterior along a drainage cavity behind the exterior surface. Infiltrated rainwater can result in damage to cladding systems, rotting and decay of wood components or decreased performance of the insulation. Next to the watertightness of the joints, the seal must also ensure the airtightness of the joints to limit the airflow through the joints and to reduce the pressure difference over the exterior surface acting as a driving force for water entry.

Moreover, the seal must be resilient to differential movements of the facade elements due to wind loading or thermal expansion and contraction. The air- and watertightness of the seal must be preserved even if the panels are moving relative to each other in all directions. The elasticity and flexibility of the seal should be sufficient to avoid the formation of cracks. In case cracks or deficiencies are present at the exterior surface of the seal, water penetration to the interior side of the joint should be prevented. Additionally, the seal should be able to accommodate tolerances on the installation of the facade elements and tolerances on the facade elements themselves. In case the joint width differs over a building within the prescribed tolerance limits, the same sealing system should be able to seal all joints effectively air- and watertight.

Object of the Invention

An object of the invention may be to provide an air- and watertight sealing of joints between different building envelope components that overcomes the above mentioned disadvantages.

Another object of the invention may be to provide a sealing system to seal both horizontal and vertical joints. A further object of the invention may be to provide an efficient solution to seal the intersections between both horizontal and vertical joints. An even further object of the invention may be to provide a cost efficient sealing system.

Another object of the invention may be to provide an uncomplicated method to seal joints between different building envelope components.

Summary of the Invention

Aspects of the present disclosure are to address at least the abovementioned problems and/or disadvantages and to provide at least the advantages described below. This object is achieved by a sealing strip for sealing joints between the surfaces of two adjacent components, in particular two adjacent building components (e.g. facade cladding), which has the technical features of the first independent claim.

In a first aspect, which can occur in combination with the other aspects and embodiments of the invention which are described herein, the present invention relates to the sealing strip as described above, comprising an elongated main body defining a drainage structure that forms a drainage cavity when provided between the surfaces of the two adjacent components and defining a top sealing surface that is in contact with one of the adjacent components when provided between the surfaces of the two adjacent components. The main body extends in a longitudinal direction between a first end and a second end, for example between a left end and a right end or between a right end and a left end. Preferably, the longitudinal direction is substantially coinciding with the longitudinal direction of the joint when provided between the surfaces of the two adjacent components. Furthermore, perpendicular to the longitudinal direction, the main body extends in a vertical direction between a top and bottom surface that is to be directed towards a respective adjacent component. Moreover, perpendicular to the longitudinal and vertical direction, the main body extends in a transversal direction between a front and back surface that is to be directed towards respectively the exterior and the interior of the building envelope formed by the adjacent components.

The main body may be made of a compressed or compressible material that is or can be compressed elastically. The main body is for example made of a material that can be compressed elastically up to at least approximately 60% of its uncompressed dimension. Preferably, the compressed or compressible material is an open or closed cell foam. The compressed or compressible material is for example a polyurethane foam, such as an open cell polyurethane foam. The main body may: have an open, semi-closed or closed cell structure; be pre-compressed or compressible; with or without glue layer on one or two sides of the strips; made of foam material, for example polyurethane, PU, ethylene propylene diene monomer, EPDM, polyvinyl chloride, PVC, or polyethylene, PE; made of rubber material, for example ethylene propylene diene monomer, EPDM, neoprene, polyvinyl chloride, PVC, Thermoplastic elastomers, TPE or silicone; have varying degree of hardness; or a combination of the above characteristics.

The drainage structure comprises a top drainage layer having one or more top recesses extending downward in the top surface of the body, wherein each top recess is in fluid communication with one or more drainage openings in the front surface of the body, preferably extending downward from the top surface of the body, more preferably extending from the top surface of the body to the bottom surface of the body. Moreover, none of the top recesses are in fluid communication with an opening in the back surface of the body if any. The main body comprises a recessed front portion extending backward from the front surface and comprising the drainage structure, and a back portion extending between the back surface of the main body and the front portion and comprising the top sealing surface. In other words, the back portion provides a top contact surface configured to form a sealing interface with an adjacent surface of one of the adjacent components when provided between the surfaces of the two adjacent components. Similarly, the back portion may provide a bottom contact surface configured to form a sealing interface with an adjacent surface of one of the adjacent components when provided between the surfaces of the two adjacent components.

In order to provide an effective watertight layer, the back portion, and hence the top contact surface, extends over at least 10 % of the average width B of the body, preferably over at least 20 % of the average width B of the body, more preferably over at least 30 % of the average width B of the body. In total, the area of the top contact surface forms at least 10 % of the cross-sectional area of the top surface of the body, i.e. the area of the top surface of the body including the recessed sections. Preferably at least 20 %, more preferably over at least 30 % of the cross-sectional area of the top surface. Hence, a sufficiently wide contact will be present when viewed perpendicular to the longitudinal direction, i.e. in the transversal direction extending from the front surface to the back surface. Advantageously, the risk of water infiltration beyond the sealing strip will be significantly reduced compared to the silicon or rubber seal systems of US 2019/0078323 Al, which have a substantially hollow shape with a triangular crosssection, wherein the contact interface is formed by a narrow line contact. Other advantageous of the solution according to the invention are a more compact solution, an integrated solution and lighter in weight than conventional silicon or rubber seals. In addition irregularities in the surface of the adjacent components have less influence compared to sealing systems with a narrow line contact

The sealing strip of the present invention may be regarded as a generic weather tight sealing system which can be used to seal vertical and transversal joints and the intersections between both. The system may ensure a more reliable weather tightness compared to existing solutions and may be less complicated to install.

The specific geometry of the solution allows the combination of (the functions of) a rainscreen, one or more pressure equalized drainage cavities, an intermediate drainage structure and a back airtight layer in a single sealing element. The rainscreen is the most exterior surface of the sealing system and keeps out most of the rain. It includes drainage openings through which infiltrated water can be drained back to the exterior. The drainage openings also ensure that the pressure in the drainage cavity is equalized with the outside air.

As all the required functions to provide a reliable weather tight seal are combined in one sealing element, the number of work steps in the field is also minimal. This reduces the risk of installation errors and therefore also the probability of deficiencies through which a large amount of water can penetrate. Furthermore, no special skilled workers are necessary to install the foam sealing strips as the risk of errors resulting in infiltrated water and damage is minimized by the specific geometry of the foam sealing strips and the provided drainage possibilities. Moreover, the airtightness of the foam sealing strip increases towards the interior side of the joint. This ensures that the pressure difference, which is one of the primary forces driving water through the joint, is reduced towards the exterior surface. This reduction of the pressure difference combined with one or more drainage cavities with the specific geometry of the invention, significantly reduces the likelihood of water reaching the interior side of the joint.

In preferred embodiments, which can occur in combination with the other aspects and embodiments of the invention which are described herein, the present invention relates to the sealing strip as described above, wherein the back portion has a substantially uniform structure, i.e. a non-porous structure without void spaces in a material or a porous structure without void spaces having a relative great size compared to the size of the pores in a porous material, e.g. a porous structure without void spaces larger than double the average pore size. In a further preferred embodiments, which can occur in combination with the other aspects and embodiments of the invention which are described herein, the present invention relates to the sealing strip as described above, wherein the sealing strip has a substantially uniform structure or is formed by a plurality of different elements with has a substantially uniform structure. For example, the sealing strip may be formed by a front part made of a first flexible foam material and a back part made of a second flexible foam material, wherein the foam body parts are adhered to an EPDM foil.

In preferred embodiments, which can occur in combination with the other aspects and embodiments of the invention which are described herein, the present invention relates to the sealing strip as described above, wherein the sealing strip is formed by a sealing strip, wherein the bottom surface of the body is provided with a glue layer and optionally a cover layer covering the glue layer. The additional advantage of the sealing strip of the present embodiment is that, next to water infiltration in the joint between two adjacent components being prevented by collecting water infiltrated between the top surface of the sealing strip and the bottom surface of the top component, the presence of the glue layer between the bottom surface of the sealing strip and the top surface of the bottom component provides an additional barrier preventing water infiltration.

According to an embodiment, the present invention relates to the sealing strip as described above, wherein, in the longitudinal direction of the body, the top drainage layer or the drainage cavity extends over at least 80 % of the length L of the body, preferably over at least 90 % of the length L of the body, more preferably over approximately the length L of the body. Hence, at a majority of the longitudinal positions (at least 80 %), a recess will be present when viewed perpendicular to the longitudinal direction, i.e. in the transversal direction extending from the front surface to the back surface. Advantageously, the risk of water infiltration between the sealing strip and the surface of the component will be significantly reduced.

In a second aspect, which can occur in combination with the other aspects and embodiments of the invention which are described herein, the present invention relates to the sealing strip as described above, wherein the drainage cavity further comprises a bottom drainage layer having one or more bottom recesses extending upward in the bottom surface of the body, wherein each bottom recess is in fluid communication with at least one of the drainage openings in the front surface of the body.

According to an embodiment, the present invention relates to the sealing strip as described above, wherein at least one recess of the bottom drainage layer is in fluid communication with at least one recess of the top drainage layer. Preferably, each bottom recess is in fluid communication with each top recess.

In a third aspect, which can occur in combination with the other aspects and embodiments of the invention which are described herein, the present invention relates to the sealing strip as described above, wherein the drainage cavity further comprises at least one intermediate drainage layer having one or more intermediate cavities extending in the body, wherein each intermediate cavity is in fluid communication with at least one recess of the top drainage layer and/or in fluid communication with at least one recess of the bottom drainage layer.

According to an embodiment, the present invention relates to the sealing strip as described above, wherein each intermediate cavity is in fluid communication with each top recess and/or each bottom recess.

In a fourth aspect, which can occur in combination with the other aspects and embodiments of the invention which are described herein, the present invention relates to the sealing strip as described above, wherein the top drainage layer comprises exactly one top recess formed by a continuous top recess, each intermediate drainage layer comprises exactly one intermediate cavity formed by a continuous intermediate cavity, and/or the bottom drainage layer comprises exactly one bottom recess formed by a continuous bottom recess. According to an embodiment, the present invention relates to the sealing strip as described above, wherein at least one top recess, continuous intermediate cavity and/or bottom recess comprises a T-shaped L-shaped or I-shaped section. Preferably, the continuous top recess, each continuous intermediate cavity and/or the continuous bottom recess comprises a T-shaped L-shaped or I-shaped section.

According to another embodiment, the present invention relates to the sealing strip as described above, wherein at least one top recess, continuous intermediate cavity and/or bottom recess is maze-shaped, T-shaped or L-shaped. Preferably, the continuous top recess, each continuous intermediate cavity and/or the continuous bottom recess is mazeshaped, T-shaped or L-shaped.

In a fifth aspect, which can occur in combination with the other aspects and embodiments of the invention which are described herein, the present invention relates to the sealing strip as described above, wherein the top drainage layer comprises multiple discontinuous top recesses, each intermediate drainage layer comprises multiple discontinuous intermediate cavities, and/or the bottom drainage layer comprises multiple discontinuous recesses. The term “discontinuous recesses” or “discontinuous cavities” as used herein means recesses or cavities that are not in direct fluid communication with each other.

According to an embodiment, the present invention relates to the sealing strip as described above, wherein each discontinuous top recess, discontinuous intermediate cavity, and/or discontinuous bottom recess is in fluid communication with a different drainage opening in the front surface of the body. According to another embodiment, the present invention relates to the sealing strip as described above, wherein each discontinuous top recess, discontinuous intermediate cavity, and/or discontinuous bottom recess comprises a rod-shaped or whistle-shaped section.

In a sixth aspect, which can occur in combination with the other aspects and embodiments of the invention which are described herein, the present invention relates to the sealing strip as described above, wherein the body comprises a slanted surface at the bottom of one or more of the top recesses, wherein the slanted surface is downwardly slanted toward the front surface at a slanted angle a relative to a transversal direction of the body perpendicular to the longitudinal direction of the body. The transversal direction extends from the back surface of the body toward the front surface of the body, or vice versa. Advantageously, water received in the top recesses will be efficiently guided towards the respective drainage opening in the front surface of the body.

Moreover, the present invention relates to foam sealing strip, comprising a sealing strip as described above made of a soft and flexible foam material. For example a partially compressed, open-cell soft foam which undergoes delayed recovery after compression and subsequent release.

The foam sealing strips may be either pre-compressed and decompress after being applied to the joints or are compressed during installation in the joint. In case the sealing strips are installed with sufficient compression, they are more resilient to differential movements of the facade components compared to elastomeric sealants, e.g. on top of a backer rod.

The cell-structure of foam sealing strips may be closed, semi-closed or open. Closed-cell strips, e.g. EPDM, have a low air permeability and need less compression than open-cell strips to be watertight. The advantage of open-cell strips is that it is possible to impregnate these strips to provide additional properties such as a delayed recovery after compression, increased fire resistance or improved watertightness.

Advantageously, the necessity of a high degree of compression of the foam sealing strips to be weather tight is eliminated. With existing foam sealing strips a large degree of compression is necessary when the strips are installed in the joint to be able to cover irregularities of the substrate and to provide a watertight connection with other sealing strips. This high degree of compression is however, difficult to achieve for every type of joint with the existing products. Also due to differential movements of the facade components, the joint width can increase, resulting in a reduced degree of compression. The high degree of compression is no longer necessary due to the presence of one or more drainage cavities which are pressure equalized with the outside air. In case water is forced through pinholes at the interface between the foam sealing strip and the facade components or between two foam sealing strips, it will enter a drainage cavity over the whole length of the joint. Because of the specific geometry of the drainage cavity and the fact that the reduced pressure difference will not be able to drive the water further into the joint, the infiltrated water will flow along the cavity towards one of the drainage openings. Therefore, the risk of severe damage caused by infiltrated water is significantly reduced. Yet another advantage is that the foam sealing strips can be easily replaced or removed. In case one of the facade components needs to be replaced or removed, e.g. when it shows damage or when a window is being replaced by an opaque element, it is not possible to simply take out one of the elements and replace them with any other element when they are sealed with the existing solutions applying a rainscreen principle. These systems either interlock, require specific edge finishes or the sealing system needs to be inserted from top to bottom after installation of the elements. In contrast when only one facade element that is sealed with our solution needs to be replaced, a part of the foam sealing strip can be cut loose and pulled out of the joint. After the replacement of the facade component, a new foam sealing strip can be installed.

Thanks to the reduced pressure difference over the exterior layer of the foam sealing strip and the drainage possibilities, the joints between the new foam sealing strip and the original strip will not result in any additional leakage paths to the interior side of the joint Moreover, the present invention relates to a sealing tape, comprising a sealing strip according to any one of the preceding claims, wherein at least the bottom surface of the body is provided with a glue layer and optionally a cover layer covering the glue layer. According to an embodiment, both the bottom and the top surface of the body are provided with a glue layer and optionally a cover layer covering the glue layer.

Moreover, the present invention relates to a building envelope, comprising two adjacent components and a sealing strip sealing joints between the surfaces of the two adjacent components, said sealing strip comprising a body extending between a left and right end, wherein the body defines a drainage structure that forms a drainage cavity between the body and at least one of the surfaces of the two adjacent components. The drainage structure comprises a top drainage layer having one or more top recesses extending downward in the top surface of the body forming a top drainage cavity, wherein each first recess is in fluid communication with a drainage opening in the front surface of the body.

Moreover, the present invention relates to a method for sealing joints between the surfaces of two adjacent components, comprising the steps of providing a main body and forming the sealing strip as described above by: forming a drainage structure comprising a top drainage layer having one or more top recesses extending downward in the top surface of the body and forming at least one drainage opening in the front surface of the body such that each top recess is in fluid communication with a drainage opening in the front surface of the body.

According to a first embodiment, the present invention relates to the method as described above, wherein the step of forming the at least one drainage opening occurs simultaneously with the step of forming the drainage structure. The method may further comprise the step of providing the body between the surfaces of two adjacent components with the top surface of the body facing the surface of one of the two adjacent components such that a drainage cavity is formed by the drainage structure.

According to a second embodiment, the present invention relates to the method as described above, wherein the method further comprises the step of providing the body between the surfaces of two adjacent components with the top surface of the body facing the surface of one of the two adjacent components such that a drainage cavity is formed by the drainage structure and wherein the step of forming the at least one drainage opening occurs after providing the body between the surfaces of two adjacent components.

In further embodiment, which can occur in combination with the other aspects and embodiments of the invention which are described herein, the present invention relates to the method as described above, wherein the step of providing the body between the surfaces of two adjacent components comprises providing a first of the two adjacent components, providing the body with the bottom surface of the body facing the surface of the first component, and comprises providing the second of the two adjacent components with the top surface of the body facing the surface of the second component.

Brief description of Drawings

The invention will be explained in more detail below with reference to drawings in which illustrative embodiments thereof are shown. They are intended exclusively for illustrative purposes and not to restrict the inventive concept, which is defined by the appended claims.

Figures 1A-6B schematically show perspective and cross-sectional views of foam sealing tapes according to multiple embodiments of the present invention forming at least one continuous drainage cavity during use;

Figures 7A-11B schematically show perspective and cross-sectional views of foam sealing tapes according to multiple embodiments of the present invention forming multiple discontinuous drainage cavity during use;

Figure 12 schematically shows sectional views of foam sealing tapes according to multiple embodiments of the present invention forming multiple discontinuous drainage cavity during use;

Figure 13 shows experimental results of a comparison between embodiments of the present invention and conventional foam sealing tapes.

Detailed Description of Embodiments

The present disclosure will be described with respect to particular embodiments and with reference to certain drawings but the disclosure is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the disclosure.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the disclosure can operate in other sequences than described or illustrated herein.

Moreover, the terms top, bottom, back, front and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. The terms so used are interchangeable under appropriate circumstances and the embodiments of the invention described herein can operate in other orientations than described or illustrated herein.

Furthermore, the various embodiments, although referred to as “preferred” are to be construed as exemplary manners in which the disclosure may be implemented rather than as limiting the scope of the disclosure.

The term “comprising”, used in the claims, should not be interpreted as being restricted to the elements or steps listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising A and B” should not be limited to devices consisting only of components A and B, rather with respect to the present disclosure, the only enumerated components of the device are A and B, and further the claim should be interpreted as including equivalents of those components.

Different aspects of the present disclosure will be described more fully hereinafter with reference to the enclosed drawings. The embodiments disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects set forth herein.

Figures 1 A-l IB show a foam sealing tape providing an air- and watertight sealing of joints between different building envelope components 2. The sealing tape la-m is formed by a foam body 10 extending in a longitudinal direction x between a left and right end, and as sown in the cross-sectional views IB, 2B, . . ., 1 IB, in a transversal direction y between a front and back surface 13, 14 and in a vertical direction z between a top and bottom surface 11, 12. The foam body 10 can have an open-cell, a semi-closed or a closed cell structure or can be composed of a combination of layers with different cellstructures. The tape is either pre-compressed and decompresses once installed in the joint or is compressed when installed in the joint. The foam sealing tape can be impregnated to provide the characteristics for a delayed recovery from its pre-compressed state.

The foam body 10 may be provided with a self-adhesive layer on at least one side of the tape to be able to be positioned in the joint. The thickness and the width of the tape can differ depending on the dimensions of the facade components and the joint width that needs to be sealed. The thickness of the tape is understood as the dimension of the surface of the tape facing the exterior or interior side of the joint. The width of the tape is understood as the dimension of the surface of the tape that is faced towards the adjacent facade components.

The specific geometry of the foam sealing tape is characterized by a drainage structure formed by taking out a specific shape of the foam tape or formed by a foam body provided with recesses 21a-k, 22c-f, 22j-k extending in the surface of the body. Hence, the drainage structure forms at least one drainage cavity when provided between the surfaces of two adjacent building envelope components. Multiple drainage cavities may be formed by forming multiple spatially distant recesses, as shown in Figures 4-12, or by combining or integrating different sealing tapes, as shown in Figure 3. The drainage structure may be vertically layered such that a top drainage layer comprising one or more top recess extending downward in the top surface of the foam body and/or a bottom drainage layer comprising one or more bottom recess extending upward in the bottom surface of the foam body.

The drainage cavities can be continuous over approximately the whole length of the sealing tape, as shown in Figures 1-6. Multiple of these cavities can be present over the width of the sealing tape, as shown in Figure 4. Or the cavities can be discontinuous over the length of the cavity, as shown in Figures 7-11. Discontinuous drainage cavities over the length of the sealing tape can be provided by small channels in the sealing tape. These channels can have various shapes. The channels should be foreseen at least at the nonadhesive side of the foam sealing strip and be oriented upward in the vertical joints and preferably have a sloped bottom surface towards the exterior in the transversal joint. The channels are applied in a way that in case water drops infiltrate at any point over the width of the joints, the water drops will reach one of the channels and will be drained back to the exterior.

In any case, it needs to be ensured that when water is flowing from the exterior side of the joint towards the interior side at any point of the length of the sealing tape, it will pass a drainage cavity that is connected to the exterior. As such, in the longitudinal direction x of the body, the top drainage layer or the drainage cavity may extend over at least 80 % of the length L of the body, preferably over at least 90 % of the length L of the body, more preferably over approximately the whole length L of the body.

Most of the rainwater running off the facade components is kept out either by means of a front wall 23 of the foam sealing tape in front of the drainage cavity, also called rainscreen, or by the upward oriented geometry of the drainage cavity, combined with a pressure equalization of the drainage cavity. Pressure equalization is achieved by the presence of at least one drainage opening 20 in the rainscreen which connect the drainage cavity to the exterior. The dimensions and number of drainage openings should be large enough to provide sufficient drainage capacity combined with a sufficient degree of pressure equalization, and small enough to prevent raindrops from flowing directly toward the drainage cavity due to their kinetic energy.

Figures 4 A and 4B show that several drainage cavities can be implemented over the width of the sealing tape in the transversal direction y. These cavities are divided by layers of the foam sealing tape called transversal drainage walls 25. Transversal openings 26 are present in the transversal drainage walls to connect the cavities over the width of the tape and pressure equalize the cavities with each other. The most interior wall of the foam sealing tape, i.e. the back wall 24 of the foam body, does not include any openings and is the most airtight layer of the foam sealing tape. The increased airtightness of the interior layer of the foam sealing strip can be obtained by the absence of any openings and preferably combined with a higher degree of impregnation, an increased density of the layer of tape and/or a larger thickness of the layer resulting in larger degree of compression.

Figures 6 A and 6B show that several drainage cavities can be implemented over the thickness of the sealing tape in the vertical direction z. These cavities are divided by layers of the foam sealing tape called vertical drainage walls 25’. Vertical openings 27 may be present in the vertical drainage walls to connect the cavities over the thickness of the tape and pressure equalize the cavities with each other.

The cross-section of the foam sealing tape can have a C-shape, comprising a continuous drainage cavity over the length of the tape within the C-shape. The cavity is facing towards one side of the joint, preferably the non-adhesive side, or towards both sides of the joints in case two C-shaped sealing tapes are combined, as shown in figures 3A and 3B. The overlap of the vertical and transversal drainage cavity is ensured by the asymmetry of the C-shape.

Figure 13 is a graph showing the results of an experiment in which tests are performed within the conditions prescribed by EN 1027:2016. Water is sprayed by means of a spraying rack and a full circular cone nozzle at a distance of 250 mm from the external surface of the test specimen and at an angle of 120°. A spray rate of approx. 2 1/min.m² is applied. First, water is sprayed for 15 minutes without any pressure difference over the specimen. Then, the pressure is raised in steps of 50 Pa up to a pressure of 300 Pa. Afterwards, pressure increments of 150 Pa are applied. The location and pressure at which water penetrates the test specimen are reported. The left graph shows the pressure difference at first sign of water leakage at adhesive and non-adhesive side of each evaluated joint with and without drainage structure per specimen.

In the experiment, conventional sealing tapes are compared to respectively sealing tapes having discontinuous drainage cavities (specimen 1 : 8 mm discontinuous drainage cavities at 30° relative to the front surface) and sealing tapes having continuous drainage cavities (specimen 2: combination of four foam body parts adhered to EPDM foil with 10 mm continuous drainage cavity). Unless otherwise mentioned, all specimens were made of a pre-compressed open cell polyurethane foam with a length of 1000 mm, a width of 40 mm and compressed thickness corresponding to the 15 mm when installed in between aluminium rectangular profiles.

In this experiment, a noticeable increase in pressure difference at first sign of water leakage at the non-adhesive side can be determined from the graph. It should be noted that the increase in pressure difference is observed for both the average pressure difference and the minimal pressure difference for three tested sealed joints. It can thus be concluded that an improved resistance to water penetration was obtained in case a drainage structure with drainage openings towards the exterior was present in the foam sealing tape compared to the foam sealing tape without drainage structure.

Other alternatives and equivalent embodiments of the present invention are conceivable within the idea of the invention, as will be clear to the person skilled in the art. The scope of the invention is limited only by the appended claims.

List of reference signs

1. Foam Sealing Tape

2. Building Envelope Component

10. Sealing Body

11. Top Surface of the Sealing Body

12. Bottom Surface of the Sealing Body

13. Front Surface of the Sealing Body

14. Back Surface of the Sealing Body

20. Drainage Opening in the Sealing Body

21. Top Recess in the Sealing Body

22. Bottom Recess in the Sealing Body

23. Front Wall of the Sealing Body

24. Back Wall of the Sealing Body

25. Drainage Wall of the Sealing Body

26. Transversal Opening in a Drainage Wall

27. Vertical Opening in a Drainage Wall x. Longitudinal direction y. Transversal direction z. Vertical direction

Claims

1. A sealing strip for sealing joints between the surfaces of two adjacent components, said sealing strip comprising a body extending in a longitudinal direction (x) between a first and second end and extending in a transversal direction (y) between a front and back surface, wherein the body comprises: a front portion extending backward from the front surface, said front portion defining a drainage structure that forms a drainage cavity when provided between the surfaces of the two adjacent components, a back portion extending between the front portion and the back surface of the main body, said back portion defining a top contact surface being configured to form a sealing interface with an adjacent surface of one of the adjacent components when provided between the surfaces of the two adjacent components, wherein the drainage structure comprises a top drainage layer having one or more top recesses extending downward in the top surface of the body, wherein each top recess is in fluid communication with one or more drainage openings in the front surface of the body, wherein, in the transversal direction (y) of the body, the top contact surface extends over at least 10 % of the width B of the body.

2. The sealing strip according to claim 1, wherein the top contact surface forms at least 10 % of the cross-sectional area of the top surface of the body.

3. The sealing strip according to claim 1, wherein each drainage opening in the front surface of the body is formed by an opening extending downward in the top surface of the body.

4. The sealing strip according to claim 1, wherein the back portion has a substantially uniform structure.

5. The sealing strip according to any one of the preceding claims, wherein, in the longitudinal direction (x) of the body, the top drainage layer or the drainage cavity extends over at least 80 % of the length L of the body, preferably over at least 90 % of the length L of the body, more preferably over approximately the length L of the body.

6. The sealing strip according to any one of the preceding claims, wherein the drainage structure further comprises a bottom drainage layer having one or more bottom recesses extending upward in the bottom surface of the body, wherein each bottom recess is in fluid communication with at least one of the drainage openings in the front surface of the body.

7. The sealing strip according to claim 6, wherein the bottom drainage layer is in fluid communication with the top drainage layer.

8. The sealing strip according to claim 7, wherein each bottom recess is in fluid communication with each top recess.

9. The sealing strip according to any one of the preceding claims, wherein the top drainage layer comprises exactly one top recess formed by a continuous top recess and/or the bottom drainage layer comprises exactly one bottom recess formed by a continuous bottom recess.

10. The sealing strip according to any one of the preceding claims, wherein the top drainage layer comprises multiple discontinuous top recesses that that are not in direct fluid communication with each other and/or the bottom drainage layer comprises multiple discontinuous recesses that that are not in direct fluid communication with each other.

11. The sealing strip according to claim 7, wherein each discontinuous top recess and/or each discontinuous bottom recess is in fluid communication with a different drainage opening in the front surface of the body.

12. The sealing strip according to any one of the preceding claims, wherein the body comprises a slanted surface at the bottom of one or more of the top recesses, wherein the slanted surface is downwardly slanted toward the front surface at a slanted angle (a) relative to the transversal direction (y) of the body perpendicular to the longitudinal direction (x) of the body. 19

13. The sealing strip according to any one of the preceding claims, wherein said body is made of a foam material.

14. A sealing tape comprising a sealing strip according to any one of the preceding claims, wherein at least the bottom surface of the body is provided with a glue layer and optionally a cover layer covering the glue layer.

15. Building envelope comprising two adjacent component (2) and a sealing strip (1), preferably according to any one of the preceding claims 1-13, sealing joints between the surfaces of the two adjacent components, said sealing strip comprising a body extending in a longitudinal direction (x) between a first and second end and extending in a transversal direction (y) between a front and back surface, wherein the body comprises: a front portion extending backward from the front surface, said front portion defining a drainage structure that forms a drainage cavity between the body and at least one of the surfaces of the two adjacent components, a back portion extending between the front portion and the back surface of the main body, said back portion defining a top contact surface forming a sealing interface with the at least one of the surface, wherein the drainage structure comprises a top drainage layer having one or more top recesses extending downward in the top surface of the body, wherein each top recess is in fluid communication with one or more drainage openings in the front surface of the body, wherein, in the transversal direction (y) of the body, the top contact surface extends over at least 10 % of the width B of the body.

16. Method for sealing joints between the surfaces of two adjacent components, preferably using a sealing strip according to any one of the preceding claims 1-13 or a sealing tape according to claim 14, comprising the steps of: providing a body with a drainage structure comprising a top drainage layer having one or more top recesses extending downward in the top surface of the body, and further comprising in any order the steps of: 20 forming at least one drainage opening in the front surface of the body such that each top recess is in fluid communication with a drainage opening in the front surface of the body; and providing the body between the surfaces of two adjacent components with the top surface of the body facing the surface of one of the two adjacent components such that a drainage cavity is formed by the drainage structure.

17. Method according to claim 16, wherein the providing the body between the surfaces of two adjacent components comprising the substeps of: before forming the at least one drainage opening, providing the body on the surface of one of the two adjacent components with the top surface of the body facing the surface of the one of the two adjacent components such that a drainage cavity is formed by the drainage structure or with the bottom surface of the body facing the surface of the one of the two adjacent components; and after forming the at least one drainage opening, providing the other of the two adjacent components respectively against the bottom surface of the body or against the top surface of the body such that a drainage cavity is formed by the drainage structure.

RECTIFIED SHEET (RULE 91) ISA/EP