EP-4741596-A1 - WALL SETUP FOR IMPROVED FIRE RESISTANCE OF BONDED DRYWALLS

EP4741596A1EP 4741596 A1EP4741596 A1EP 4741596A1EP-4741596-A1

Abstract

Inventors

ALTENWEGNER, Florian

Assignees

Sika Technology AG

Dates

Publication Date: 20260513
Application Date: 20241111

Claims (15)

Plasterboard having a stepped single lap joint on at least two opposing edges thereof, wherein the respective steps at the opposing edges are arranged at with touching transition to the respective opposing main faces of the plasterboard.
Plasterboard according to claim 1, having stepped single lap joints on all edges thereof.
Plasterboard according to claim 1 or 2, wherein the step at one edge has a thickness in the range of 50 to 65% of the thickness of the plasterboard, preferably in the range of 50 to 60%, and on the respective opposing edge has a thickness of 100% of the thickness of the plasterboard - the thickness of the step at the one edge - a space of up to 5% of the thickness of the board.
Plasterboard according to any one of claims 1 to 3, wherein the step has a length of at least 1.5 cm, preferably in the range of 2 cm to 6 cm and more preferably in the range of 2.5 to 5 cm.
Plasterboard according to any one of the preceding claims, wherein the stepped single lap joint has a radius of 2 to 7 mm, preferably 3 to 6 mm and more preferably 4 to 5 mm.
Plasterboard according to any one of the preceding claims, wherein the plasterboard has a thickness in the range of from 10 to 25 mm and preferably 12 to 20 mm.
Plasterboard according to any one of the preceding claims, wherein the plasterboard has a paper or cardboard coating on at least one major face thereof, preferably on both major faces thereof.
Plasterboard according to claim 7, wherein the paper or cardboard coating has a fire retardant integrated therein, preferably wherein a fire retardant is impregnated into the paper or cardboard coating.
Drywall construction comprising a wooden or metal truss and a plurality of plasterboards according to any one of claims 1 to 8, which arranged on the truss in an overlapping manner, so at the overlap a step of a first plasterboard is arranged at the proximal side of the truss and is covered by at least 80% by a step of a second plasterboard on the distal side of the truss.
Drywall construction according to claim 9, wherein a plurality of plasterboards is arranged on the truss in an overlapping manner, so at the overlap a step of a first plasterboard is arranged at the proximal side of the truss and is covered by at least 90% and preferably at least 95% by a step of a second plasterboard on the distal side of the truss.
Drywall construction according to claim 9 or 10, wherein the plasterboards are connected to the truss and/or to one another by means of an adhesive, preferably wherein the connection to the truss and between the plasterboards is by means of the same adhesive.
Drywall construction according to any one of claims 9 to 11, wherein the dry wall has layers of plasterboards on both main faces of the truss, preferably a single layer of plasterboards on both main faces.
Process for the production of a dry wall construction according to any one of 9 to 12, which comprises the following steps: - Providing a wooden or metal truss; - Attaching a first plasterboard according to any one of claims 1 to 8 to the truss; - Attaching subsequent plasterboard according to any one of claims 1 to 8 to the truss in a manner, that the respective steps of the plasterboards overlap each other in a closed fit of the steps.
Process according to claim 13, wherein the attachment of the plasterboards to the truss and/or the attachment of the plasterboards to one another via the stepped edges is provided by an adhesive and preferably by the same adhesive.
Use a stepped single lap joint in a plasterboard for improving the fire resistance of a drywall construction, wherein the plasterboards are arranged with respective overlapping lap joint steps to form a continuous surface of the drywall at the transitions of one plasterboard to a subsequent plasterboard.

Description

The present invention is concerned with plasterboards having a stepped single lap joint on at least two opposing edges thereof, wherein the respective steps at the opposing edges are arranged with a touching transition to the respective opposing main faces of the plasterboard. The present invention is further concerned with a drywall construction, which is prepared with respective plasterboards, a process of producing a respective drywall construction and a use of stepped single lap joint in a plasterboard for improving the fire resistance of a drywall construction. State of the art In a conventional bonded drywall plasterboards, which may be constituted from gypsum (possibly including fibers) or concrete, are mounted on a core or skeleton under construction, which is usually a wooden or metal truss. Such plasterboards regularly have slightly curved or shaped edges, so that the mounted boards in the drywall have small gaps or butt joints between them. To cover these gaps, in drywall production, a putty or filler is applied into the gap to fill the same. In addition, often, a reinforcing tape is applied onto the putty filled gaps, which is again covered by a thin layer of putty, before the surface of the drywall is smoothened by sanding. A problem, which arises when such drywalls are exposed to a fire, is that the face of the drywall, which is exposed to the fire first expands due to the heat and after that experience some shrinking due to the drying effect. This motion of the drywall boards leads to the formation of cracks in the butt joints, so that a channel is opened and the heat and fire can much more easily enter the inside of the drywall, where the truss is provided. If such truss is made from wood, the truss will immediately start to burn. If the truss is made from metal, the heated metal will transfer the thermal energy to the other side of the wall. If the plasterboards are attached to the truss by means of an adhesive, the adhesive on the side which is distal to the fire will then also be heated up to a level where the plasterboards start to become detached from the drywall. In the event, that a stream of water is then applied to the drywall, the wall can easily collapse, as either the truss has been decomposed by the fire or the boards are no longer bonded to the truss. This represents a certain danger for firefighters who are trying to extinguish the fire or try to stop the fire from spreading further. A possible solution to the problem of providing a more fire safe drywall construction is the preparation of a drywall with two layers of plasterboards, where the respective layer are positioned such that the gaps, which are formed from the butt joints of the plasterboards, which are directly attached to the truss, are covered by plasterboards which are applied in a second layer. As at the same time, the butt joints in the second layer at their bottom are closed by the first layer, even if cracks are formed in the butt joints of the second layer, the fire cannot directly access the interior of the drywall, where the truss is positioned. A disadvantage of such constructions is on the other hand, that the production of drywalls with two layers of plasterboards increases costs and production effort of the construction and is comparatively inflexible as plasterboards are usually only available in certain thickness grades. There is therefore a need for the provision of drywalls with enhanced fire-protection performance, which can more easily be fabricated with only a single layer of plasterboards. The present application addresses this need. Description of the invention In the investigation, which are underlying the present invention, is has been found that the provision of a plasterboard with a stepped edge single lap joint on at least two opposing edges therefore allows the formation of a butt joint of the plasterboards, where an occurrence of a crack does not open a direct path into the inside of the dry wall construction. Whereas with such construction a crack may still form, the underlying stepped edge of the board blocks such direct path, especially, when the extended part of the stepped edge for the upper plasterboard is on the inside of the wall construction. In contrast to a construction with notches in one plasterboard and corresponding extensions in an adjacent plasterboard (as is known e.g. from laminate floors), a construction as a stepped edge allows the extended part to be thicker, which is beneficial for the resilience of the plasterboard edge towards breaking. Accordingly, in a first aspect, the present invention pertains to a plasterboard having a stepped single lap joint on at least two opposing edges thereof, wherein the respective steps at the opposing edges are arranged at with touching transition to the respective opposing main faces of the plasterboard. In the respective plasterboards, the indication "wherein the respective steps at the opposing edges are arranged at with touchin