Method of reusing building boards

Abstract

A method of reusing building boards used to form a structure, such as a wall or a ceiling, of a building, wherein at least one surface covering liner (4) is directly glued against an entire exposed main surface (11, 12) of building boards (S1, S2), such that the surface covering liner covers the building boards (S1, S2), wherein said gluing was performed using a soluble glue. The method comprises: applying (301) a solvent to the surface covering liner (4), including the glue, removing (302) the surface covering liner (4), whereby the fasteners (3) are exposed, removing (303) the fasteners (3), and recovering (304-306) the building boards (S1, S2).

Description

[0001] METHOD OF REUSING BUILDING BOARDS

[0002] Technical field

[0003] The present document relates to a method for recovering building boards for reuse.

[0004] Background

[0005] WO2012152994A1 discloses a building board which is suitable for interior walls and ceilings. The building board has a joint edge with a profile that causes adjacent building boards to engage with each other and prevent relative movement between the building boards as seen in a direction perpendicular to the main plan of the building boards.

[0006] An advantage of those in WO2012152994A1 is that they, thanks to the profiled joint edge, requires relatively little puttying to achieve an acceptable smoothness of the formed interior wall or ceiling.

[0007] A further development is known from W02021076035A2, which discloses a method of forming a surface of an interior wall or ceiling, that eliminates the need for puttying.

[0008] With the building industry striving, as many other industries, for increased sustainability, there is an increased desire for being able to reuse building materials.

[0009] Summary

[0010] It is an object to provide an improved way of reusing building materials. A particular object is to provide a method for reusing building boards, such as wall panels or ceiling panels.

[0011] The invention is defined by the appended independent claims. Embodiments are set forth in the dependent claims, in the following description and in the appended drawings.

[0012] According to a first aspect, there is provided a method of reusing building boards used to form a structure, such as a wall or a ceiling, of a building, the structure comprising at least one framing member, a pair of building boards, comprising a first building board and a second building board, attached to the framing member using releasable fasteners, wherein each of the building boards has a pair of parallel and opposite main surfaces, wherein edge portions of the building boards have a locking system, for mechanically locking the building boards relative to each other in a direction perpendicular to the main surfaces, to form a joint with a joint plane defined as a plane which is perpendicular to the main surfaces and which comprises an outer edge of at least one of the main surfaces, wherein at least one surface covering liner is directly glued against an entire exposed main surface of the building boards, such that the surface covering liner covers the building boards, wherein said gluing is performed using a soluble glue. I.e. a soluble glue was used when the surface covering liner was glued against the main surface of the building boards. The method comprises applying a solvent to the surface covering liner, including the glue, i.e. the soluble glue, removing the surface covering liner, whereby the fasteners are exposed, removing the fasteners, and recovering the building boards.

[0013] The term “reuse” implies that the material is being used again in essentially its original form.

[0014] The term “mechanically locking the building boards” implies that the locking of the building boards is performed only mechanically, i.e. without any kind of glue or adhesive.

[0015] By “surface covering liner” is meant a thin flexible sheet that is formed to completely cover a wall, either to form a finished surface, or to form a paintable surface. The liner may be thin, preferably 0.1-2 mm thick.

[0016] Thus, the surface covering liner can be a wallpaper or a wall covering web. A wall covering web can be primed, pre-painted, and or painted once or more while in situ.

[0017] The surface covering liner may comprise reinforcement fibers, a nonwoven fabric, such as fiber web or a nonwoven web. Fibers can comprise one or more of glass fibers, wood-based fibers, such as paper fibers, and polymer fibers. Specifically, the term “surface covering liner” does not cover such products as tape, joint strips, puttying strips or other products intended to be placed only over an area locally around a joint between building boards, and which thereby are not intended to cover the entire wall.

[0018] The term “releasable fastener” implies a fastener that can be removed without damaging the building boards other than any hole and / or recess provided by the fastener itself. Hence, the area of the building board surrounding the fastener is undamaged also after removal of the fastener.

[0019] By gluing the surface covering liner “directly to an exposed” surface of the building boards is meant that no intermediate puttying or other leveling strip is arranged between the main surfaces of the building boards and the surface covering liner. Thus, the surface covering liner abuts against, and is fixed to, the entire exposed main surface of one or more of the building boards.

[0020] A soluble glue is a glue that can be dissolved by a solvent. In particular, water soluble glue is contemplated, whereby the solvent may be water, optionally with one or more additives, such as other solvents or wetting agents.

[0021] By using the combination of releasable fasteners, putty-free joints and soluble glue to attach the surface covering liner, it is possible to recover the building boards, such that they can be reused, e.g. when building a new wall or ceiling.

[0022] The method may be used for any type of building boards, including homogenous building boards and layered or laminated building boards.

[0023] Examples of building boards include wood based building boards, such as plywood, chipboard, oriented strand board, medium density fiberboard, high density fiberboard, etc.

[0024] Layered building boards include mineral boards, such as plaster / gypsum having wood based surface layers of paper, cardboard, or synthetic surface layers, comprising polymer fiber or glass fiber. The method may also be used with building boards made wholly or partially of recycled materials, such as recycled wood, plastics, mineral or fabric.

[0025] The building boards may in particular be formed of a fiber-reinforced material comprising a fiber-reinforced matrix, such as fiber plaster. Fiber plaster is available, e.g., under the trademark FERMACELL® from James Hardie Europe GmbH.

[0026] In particular, the building boards may be formed of a material which provides a fire classification under the EN 13501-1 standard, corresponding to Class A2 or better, preferably Class A1 .

[0027] The surface covering liner may comprise reinforcing fibers, a web, a woven web, a nonwoven fabric or a wallpaper.

[0028] The wetting of the surface may comprise piercing the surface covering liner to allow a solvent to reach the glue. The wetting may be a part of the action of applying the solvent as the solvent may comprise a wetting agent, followed the piercing of the surface of the covering liner.

[0029] It is possible to use e.g. a roller provided with needles or cutting edges to pierce the surface covering liner sufficiently to allow a solvent, such as water, to penetrate to reach the glue.

[0030] The surface covering liner may be water permeable.

[0031] The building boards may be homogeneous.

[0032] By the building boards being "homogeneous" is meant that they consist of the same material right through. Thus, the core material in the building boards is exposed at their main surfaces. Specifically, the building boards lack surface coating layers, such as cardboard-, woven web- or non-woven web surface layers, covering the core of the building board.

[0033] The building boards may be formed of a material comprising matrix material and fiber, preferably fiber plaster.

[0034] It is particularly advantageous if the building boards are devoid of water soluble materials, such as paper or cardboard. It is particularly advantageous if the surface covering liner comprises reinforcing fibers, in particular polymer fibers or glass fibers, which increase the strength of the surface covering liner when it is wet.

[0035] There may be no glue present between the framing member and one of the main surfaces facing the framing member, and / or on a joint surface formed by the edge portions of the building boards.

[0036] A joint filler may be present on a joint surface formed by the edge portions of the building boards.

[0037] A joint filler may be applied in order to facilitate assembly of the building boards by providing a lubricant that facilitates sliding along the edge portions. A joint filler may also be used in order to reduce or eliminate any play present in the joint. The joint filler is characterized by presenting no or limited adhesion to the building boards, such that the edge portions are not damaged when disassembled. The joint filler may be soluble, such that it is sufficiently weakened by the application of a solvent, such as is the case with the glue used for the surface covering liner. Hence, the joint filler may be provided by means of a glue that may be water soluble and that may present poor adhesion to the material of the building boards. It is possible to surface treat the edge portions, e.g. by wax, oil, or the like to reduce friction and / or adhesion to the glue.

[0038] A central plane may be defined as a plane which is parallel to the main surfaces and which is equidistant from the first main surface as from the second main surface, wherein each edge portion has a constant profile along the edge portion, comprising a tongue and a groove, wherein the tongue is entirely on one side of the central plane, wherein the groove is entirely on a second side of the central plane, wherein the groove has a height, as seen in direction perpendicular to the main planes, which is at least equal a height of the tongue, wherein the groove has a depth from the joint plane, as seen in direction perpendicular to the joint plane, wherein the tongue has a protrusion from the joint plane, as seen in the direction perpendicular to the joint plane, wherein the depth of the groove is at least as large as the protrusion of the tongue, and wherein the edge portion of the second building board is joined with the edge portion of the first building board, such that the tongue of the first building board extends into the groove of the second building board and such that the tongue of the second building board extends into the groove of the first building board.

[0039] In the method, the profile may have a first edge portion extending between the tongue and the first main surface, wherein the profile has a second edge portion extending between the groove and the second main surface, and wherein the edge portions of the profiles have substantially equal extent, as seen in the direction perpendicular to the main surfaces.

[0040] In the method, the first building board may have a second edge portion, which is perpendicular to the first edge portion of the first building board and is formed the same as the first edge portion of the first building board, wherein the second building board has a second edge portion, which is perpendicular to the first edge portion of the second building board and is formed the same as the first edge portion of the second building board, wherein the first and second building boards are joined so that said second edge portions are aligned with each other, wherein said second edge portions have a constant profile along the second edge portion, which comprises at least one tongue and / or at least one groove, wherein the method comprises providing a third building board, which has a first edge portion having a constant profile along the first edge portion, which comprises at least one tongue and / or at least one groove, and wherein the method comprises joining the first edge portion of the third building board with the second edge portions of both the first and the second building board, such that the joint plane formed by the first and second building boards intersects the first edge portion of the third building board at a distance from edge portions of the third building board that are parallel to the joint plane.

[0041] An intersection point between the joint plane and the first edge portion of the third building board, as seen in a plane parallel to the main surfaces, may be at a distance from said framing member.

[0042] The building boards may be free of putty or other levelling compound along the joint. An outwardly exposed surface of the surface covering liner may be covered by at least one layer of paint.

[0043] At least some of the building boards may have a mutually identical size, with a length, a width and a thickness, wherein the length is less than about 2.5 x the width, preferably less than about 2 x the width or less than about 1 .5 x the width.

[0044] In particular, the building boards may have a format which corresponds to a standardized load carrier format, such as an ISO pallet. Non-limiting examples of such pallets include the Euro (EUR / EPAL / ISO1 ) pallet format, which is about 800x1200 mm; the 40x48 inch format used in North America, the 45.9x45.9 inch format used in Australia, the 42x42 inch format used in North America or the 1100x1100 mm format used in Asia. Other examples include the ISO2 format, which is 1200x1000 mm.

[0045] The method may further comprise placing the recovered building boards in a stack on a standardized load carrier, in particular a pallet.

[0046] The placement on the load carrier can be followed by the provision of corner protectors and / or by complete or partial covering of the stack thus formed by a water-impermeable covering, such as plastic film.

[0047] The building boards may be mounted to the framing members with length directions extending horizontally.

[0048] Brief description of the drawings

[0049] Fig. 1 a-1 b show a pair of edge portions 1 , T of building boards.

[0050] Fig. 2 shows a wall construction.

[0051] Fig. 3 shows a method for forming a wall surface.

[0052] Fig. 4 shows an arrangement of joined building boards.

[0053] Fig. 5 shows a method for disassembling a wall surface for reuse.

[0054] Detailed description

[0055] Fig. 1 a shows a pair of edge portions 1 , T of a pair of building boards S1 , S2. Each building board S1 , S2 has a body 10, a first main surface 11 and a second main surface 12, on the opposite side of the body 10. As shown in fig. 1a, the main surfaces 11 , 12 are parallel to an X-Y plane.

[0056] In the following description, the building boards S1 , S2 will be described with reference to a particular design of a system for providing a mechanical joint, locking the building boards S1 , S2 in a direction perpendicular to the main surfaces 11 , 12. However, it is understood that there are many such designs of mechanical joints, including, as a non-limiting example, traditional tongue and groove joints, which can provide a similar effect and which can thus be used in the concept described herein.

[0057] The building boards S1 , S2 have a respective edge portion 1 , T which have one edge profile with a tongue 101 , a groove 102, a first edge outer portion 103 and a second edge outer portion 104.

[0058] A central plane Pc is defined as a plane that is parallel to the main surfaces 11 , 12 and which is substantially equidistant from the first main surface 11 as from the second main surface 12, "substantially" indicates that tolerances and surface unevenness of the main surfaces may give rise to some deviation.

[0059] A joint plane Pf is defined as a plane perpendicular to the main surfaces 11 , 12 and that comprises an outer edge of at least one of the main surfaces, so that two adjacent interconnected building boards S1 , S2 meet at the joint plane. The joint plane Pf can coincide with the edge outer portions 103, 104. As is evident from fig. 1 a, the joint plane is parallel to a Y-Z plane.

[0060] The tongue 101 is entirely on one side of the central plane Pc and the groove is entirely on the other side of the central plane Pc.

[0061] As seen in projection on the joint plane Pf, an outermost point of the tongue 101 and an innermost point of the groove 102 may present the same distance to the central plane Pc.

[0062] The extents of the tongue and groove in the normal direction of the main surfaces 11 , 12 can be equal.

[0063] The protrusion of the tongue 101 outside the joint plane can be as large as, or less than, the greatest depth of the groove 102 from the joint plane. In the embodiment shown, both the tongue 101 and the groove 102 are formed with semicircular cross-sections, so that the tongue and the groove both are tangent to the center plane Pc in the same point.

[0064] Fig. 1 b schematically shows a building board as seen in plan view perpendicular to one of the main surfaces 11 , where the embodiment of the edge portions 1 , 1' is shown. As is evident, the building board S is rectangular (oblong or square) and has one first pair of adjacent and between themselves perpendicularly themselves extending edge portions 1 , the tongue and groove of which are oriented according to the left edge portion of fig. 1a with the tongue 101 closest to the exposed main surface 11 . Further, the building board S have a pair of adjacent and mutually perpendicularly extending edge portions 1', the tongue and groove of which are oriented according to the right edge portion T in fig. 1a with the groove 102 closest to the exposed main surface 11 .

[0065] The building boards may have a mutually identical size, with a length, a width and a thickness, wherein the length may be less than about 2.5 x the width, preferably less than about 2 x the width or less than about 1 .5 x the width. In particular, the length may be less than 2 m, preferably less than 1.5 m.

[0066] The thickness may be on the order of 5-30 cm, such as 5-10 mm, IQ- 15 mm, 15-20 mm, 20-25 mm or 25-30 mm.

[0067] In particular, the building boards may have a format which corresponds to a standardized load carrier format, such as an ISO pallet. Non-limiting examples of such pallets include the Euro (EUR / EPAL / ISO1 ) pallet format, which is about 800x1200 mm; the 40x48 inch format used in North America, the 45.9x45.9 inch format used in Australia, the 42x42 inch format used in North America or the 1100x1100 mm format used in Asia. Other examples include the ISO2 format, which is 1200x1000 mm.

[0068] While conventional building boards are typically sized at about 2500x900 mm up to about 3000x1250 mm and positioned with their longitudinal directions vertically, the building boards according to the preset concept are preferably smaller. Hence, while the vast majority of conventional building boards are cut to a desired length, that would typically match a wall height, only very few of the building boards according to the present concept will need to be cut, such that more of them will maintain their original size, which facilitates reuse.

[0069] With the optional feature of the tongue 101 and groove 102 being arranged mirror-inverted symmetrically around the central plane Pc, it is possible to use the building board regardless of which main surface 11 , 12 is exposed. In addition, it is to a greater extent possible to use waste pieces sawn off of the building boards S, S1 , S2 since they can be turned so that any of the main surfaces 11 , 12 is exposed.

[0070] Fig. 2 shows a schematic sectional view of a structure comprising a framing member 2, which may be a horizontal or vertical wall stud, a ceiling stud, a floor stud or a joist system. The framing member can be formed of wood, metal (usually steel, steel sheet) or composite material, such as MDF.

[0071] In the example shown, the structure comprises three building boards S, which are attached to the joist system with releasable fasteners, in particular threaded fasteners, like screws, or the like, preferably with a small head, such that the corresponding recess formed in the building board is as small as possible.

[0072] The building boards are mounted to the framing member without glue. The building boards S are attached with said fasteners placed along the joint edges 1 , T, where these overlap a framing member 2.

[0073] With the joint with tongue 101 and groove 102, it is also provided an improved stability at a distance from the framing member, since each building board engages with at least one adjacent building board.

[0074] As shown in fig. 2, a glued surface covering liner 4, such as a wallpaper, a fiber web, such as fiberglass fabric, a reinforcing fabric, a nonwoven web, such as fiber felt, or similar has been applied directly to the building board, without puttying.

[0075] Thus, the surface covering liner 4 is glued directly to the main surface 11 on both sides of each joint plane. The surface covering liner 4 is usually mounted in the form of a plurality of lengths which are arranged next to each other, either edge to edge or with a very small overlap. Each length of surface covering liner usually has a length corresponding to the height of a wall from floor to ceiling, or a ceiling length from wall to wall, taking into account tolerances and if any baseboards and / or cornices. Each length of surface covering liner can have a width, which may be in the range of 40-120 cm, preferably about 60-90 cm.

[0076] Fig. 3 shows a method for forming a wall surface.

[0077] The method comprises providing 201 at least a pair of framing members, which are arranged to form a framing member wall, a ceiling or an interior floor.

[0078] Further, the method comprises providing 202 at least a pair of building boards as described above.

[0079] Optionally, one or both of the building boards can be sawn to fit against the framing members.

[0080] A first one of the building boards is fastened 203 to at least one of the framing members 2.

[0081] A second one of the building boards is joined 204 with the first one of the building boards by interconnecting the joint edge T of the second building board with the joint edge 1 of the first building board, as shown in fig. 1a.

[0082] Then the second building board is attached 205 to at least one of the framing members 2.

[0083] A check 206 can then be made to assess whether a joint formed between the building boards is sufficiently smooth. Such control can be done by dragging across the joint with the hand.

[0084] If the joint is smooth enough, the surface covering liner can be glued 208 directly on the boards and over the joint.

[0085] If the joint is too prominent, the edge portions 1 , T at the exposed main surface 11 can be sanded 207, for example sandpapered, the joint to the desired smoothness, after which the surface covering liner is glued 208.

[0086] The method can be used when assembling walls or ceilings on site in a building that is under construction, renovation or modification. Alternatively, the method can be used in the manufacture of prefabricated building elements, such as walls, joist systems or building modules, which is then lifted with a crane or forklift, and possibly transported to construction site by truck and / or train for assembly to a building.

[0087] Referring to fig. 4, three such building boards S1 , S2, S3 are shown as shown in fig. 2.

[0088] In the example shown, the building boards S1 , S2, S3 are rectangular, and have a pair of opposite edge portions according to fig. 1 on the short sides and a pair of opposite edge portions according to fig. 1 on the long sides.

[0089] The building boards S1 and S2 are joined together along a pair of short sides, as described above.

[0090] The third building board S3 is joined along a long side with both the first building board S1 and the second building board S2, such that short sides of the third building board are offset relative to short sides of the first and second building boards.

[0091] It is understood that corresponding arrangements with offset short sides may be achieved with square building boards, or by instead joining the first and second building boards S1 , S2 long side against long side and then joining the third building board S3 along a short side with both the first building board S1 and the second building board S2, so that long sides of the third building board are offset in relation to long sides of the first and second building boards S1 , S2.

[0092] Offsetting rows of building boards S1 , S2, S3 as shown in fig. 4, such that vertical joints, and / or horizontal joints, do not necessarily overlap framing members, is possible thanks to the joining with mechanical locking in the normal direction, which is achieved with the help of the profiled edge portions 1 , 1'.

[0093] It is understood that when joining building boards in such a way as shown in fig. 4, edge panels will need to be cut in a conventional manner. By using pairs of opposite edge portions which are identical to each other on the long side and short side, increased flexibility is achieved when using waste pieces formed by cutting.

[0094] Referring to fig. 5, there is illustrated a method of recovering building boards from a construction such as the one illustrated in fig. 2. The method is illustrated with reference to a wall, but may equally be used to a ceiling, on which a surface covering liner 4 is attached using a water soluble glue.

[0095] In a first step 301 , a solvent, such as water, is applied such that the surface covering liner 4 is wetted, such as soaked, which may contain a wetting agent, such as a tenside, a further solvent or a mixture of water and / or a tenside and / or the further solvent. The solvent may be applied by means of a roller, a sponge or a spraying device. Alternatively, the solvent may be applied in the form of vapor or steam.

[0096] The solvent is allowed to penetrate behind the surface covering liner so as to soften or dissolve the glue.

[0097] In the event the surface covering liner 4 has little or no water permeability, a piercing tool may be used, such as a piercing or cutting roller, i.e. a roller having needles or cutting edges configured for cutting through the surface covering liner 4 to allow water to penetrate.

[0098] As a next step 302, the surface covering liner 4 is removed from the building boards, typically by being pulled off by hand. It may be desirable to use gripping aids to facilitate the work.

[0099] As the wall is formed without puttying, fastener 3 heads will become exposed immediately upon removal of the surface covering liner 4.

[0100] Hence, as a next step 303, fasteners 3 will be removed. In particular, all fasteners on one building board may be removed, e.g. by being unscrewed.

[0101] As a next step 304, the building board is removed from the wall in its entirety. This is facilitated as no glue is used, either between the building board and the framing member, or in the joints between the building boards S. The building board S, S1 , S2 may be placed 305 on a load carrier, such as a pallet, preferably in a stacked manner with other identical building boards. In the case where the main surfaces 11 , 12 differ from each other, it is advantageous to position all building boards in the stack with the same main surface facing upwards.

[0102] Optionally, a protection may be applied 306 to the stacked building boards. Such protection may include corner protectors (e.g. an elongate L- shaped profile), joint protectors (sheets) and / or rain protection, such as a covering of a polymer hood or a polymer wrapping. The disassembled building boards S, S1 , S2 may subsequently be transported to another location, where they may be mounted to another set of framing members, providing studs, or joists for a wall or a ceiling, in accordance with the mounting method 201-208 described above.

Claims

CLAIMS1 . A method of reusing building boards (S1 , S2) used to form a structure, such as a wall or a ceiling, of a building, the structure comprising: at least one framing member (2), a pair of building boards (S1 , S2), comprising a first building board (S1 ) and a second building board (S2), attached to the framing member (2) using releasable fasteners (3), and wherein each of the building boards (S1 , S2) has a pair of parallel and opposite main surfaces (11 , 12), wherein edge portions of the building boards (S1 , S2) have a locking system, for mechanically locking the building boards relative to each other in a direction (Z) perpendicular to the main surfaces (11 , 12), to form a joint with a joint plane (Pf) defined as a plane which is perpendicular to the main surfaces and which comprises an outer edge of at least one of the main surfaces, wherein at least one surface covering liner (4) is directly glued against an entire exposed main surface (11 , 12) of the building boards (S1 , S2) using a soluble glue, such that the surface covering liner covers the building boards (S1 , S2), wherein the method comprises: applying (301 ) a solvent to the surface covering liner (4), including the glue, removing (302) the surface covering liner (4), whereby the fasteners (3) are exposed, removing (303) the fasteners (3), and recovering (304-306) the building boards (S1 , S2).

2. The method as claimed in claim 1 , wherein said applying (301 ) the solvent comprises wetting and piercing the surface covering liner (4) to allow the solvent to reach the glue.

3. The method as claimed in claim 1 or 2, wherein the surface covering liner (4) is water permeable.

4. The method according to any one of claims 1-3, wherein the building boards (S1 , S2) are homogeneous.

5. The method according to any one of claims 1-4, wherein the building boards (S1 , S2) are formed of a material comprising matrix material and fiber.

6. The method according to any one of claims 1-5, wherein the surface covering liner (4) comprises a reinforcing fibers, a web, a woven web, a nonwoven fabric or a wallpaper.

7. The method according to any one of claims 1-6, wherein there is no glue present between the framing member and one of the main surfaces (11 , 12) facing the framing member (2), and / or on a joint surface formed by the edge portions of the building boards (S1 , S2).

8. The method as claimed in any one of the preceding claims, wherein a joint filler is present on a joint surface formed by the edge portions of the building boards (S1 , S2).

9. The method according to any one of claims 1-8, wherein a central plane (Pc) is defined as a plane which is parallel to the main surfaces (11 , 12) and which is equidistant from the first main surface (11 ) and from the second main surface (12), wherein each edge portion (1 , T) has a constant profile along the edge portion, comprising a tongue and a groove, wherein the tongue (101 ) is entirely on one side of the central plane (Pc), wherein the groove (102) is entirely on a second side of the central plane (Pc),wherein the groove (102) has a height, as seen in direction (Z) perpendicular to the main planes (11 , 12), which is at least equal a height of the tongue (101 ), wherein the groove (102) has a depth from the joint plane (Pf), as seen in direction (X) perpendicular to the joint plane (Pf), wherein the tongue (101) has a protrusion from the joint plane (Pf), as seen in the direction (X) perpendicular to the joint plane, wherein the depth of the groove (102) is at least as large as the protrusion of the tongue (101 ), and wherein the edge portion (1') of the second building board (S2) is joined with the edge portion (1 ) of the first building board (S1 ), such that the tongue (101 ) of the first building board (S1 ) extends into the groove (102) of the second building board and such that the tongue (101 ) of the second building board (S2) extends into the groove (102) of the first building board.

10. The method according to claim 9, wherein the profile has a first edge portion (103) extending between the tongue and the first main surface, wherein the profile has a second edge portion (104) extending between the groove and the second main surface (11 , 12), and wherein the edge portions of the profiles have substantially equal extent, as seen in the direction perpendicular to the main surfaces.11 . The method according to claim 9 or 10, wherein the first building board (S1 ) has a second edge portion, which is perpendicular to the first edge portion of the first building board and is formed the same as the first edge portion of the first building board, wherein the second building board (S2) has a second edge portion, which is perpendicular to the first edge portion of the second building board and is formed the same as the first edge portion of the second building board, wherein the first and second building boards (S1 , S2) are joined so that said second edge portions are aligned with each other,wherein said second edge portions have a constant profile along the second edge portion, which comprises at least one tongue (101 ) and / or at least one groove (102), wherein the method comprises providing a third building board (S3), which has a first edge portion having a constant profile along the first edge portion, which comprises at least one tongue (101 ) and / or at least one groove (102), and wherein the method comprises joining the first edge portion of the third building board with the second edge portions of both the first and the second building board, such that the joint plane (Pf) formed by the first and second building boards intersects the first edge portion of the third building board (S3) at a distance from edge portions of the third building board (S3) that are parallel to the joint plane.

12. The method according to claim 11 , wherein an intersection point between the joint plane and the first edge portion of the third building board, as seen in a plane parallel to the main surfaces, is at a distance from said framing member.

13. The method according to any one of claims 1 -12, wherein the building boards are free of putty or other levelling compound along the joint.

14. The method according to any one of claims 1 -13, wherein an outwardly exposed surface of the surface covering liner is covered by at least one layer of paint.

15. The method according to any one of claims 1 -14, wherein at least some of the building boards have a mutually identical size, with a length, a width and a thickness, wherein the length is less than about 2.5 x the width, preferably less than about 2 x the width or less than about 1 .5 x the width.

16. The method as claimed in claim 15, further comprising placing the recovered building boards in a stack on a standardized load carrier, in particular a pallet.

17. The method as claimed in claim 15 or 16, wherein the building boards (S1 , S2) are mounted to the framing members (2) with length directions of the building boards (S1 , S2) extending horizontally.

Images