NO347124B1

NO347124B1 - Log wall joint structure and a method for erecting a wall structure of stacked log elements

Info

Publication number: NO347124B1
Application number: NO20211348A
Authority: NO
Inventors: Kjell Ole Homme
Original assignee: Isokitt Norge As
Priority date: 2021-11-09
Filing date: 2021-11-09
Publication date: 2023-05-22
Also published as: NO20211348A1

Description

LOG WALL JOINT STRUCTURE AND A METHOD FOR ERECTING A WALL STRUCTURE OF STACKED LOG ELEMENTS

The invention relates to a log wall joint structure for a wall structure made of stacked log elements, wherein a joining post is arranged to engage with end portions of the stacked log elements. The end portions of the log elements comprise a through-going vertical groove arranged to receive an edge portion of a joining board forming part of the joining post, allowing the log elements to move along the joining post during shrinking and expansion due to change of dryness of the timber.

The invention also relates to a method for erecting a wall structure of stacked log elements.

Finally, the invention relates to a wall structure formed by several stacked log elements and comprising one or more log wall joint structures.

Traditionally, the corners of log walls are constructed using crib joints, by making mutually corresponding cut-outs or notches in the opposite log surfaces to be placed one over the other, so that intersecting logs can be stacked tightly on top of each other. A crib joint is massive in respect of both weight and appearance.

There are several problems or drawbacks associated with a crib corner. The log portions extending beyond the corner constitute a significant increase in log material consumption. Thermal insulation of the corner is difficult because gaps tend to be formed between the criss-cross logs as they gradually twist, contract, swell and move in different ways. Other problems associated with a crib corner are that producing a tight fit crib structure is a difficult and therefore requires highly skilled personnel, while at the same time being very time consuming and thus expensive, and that a crib joint can join only two walls together.

Several simplified log wall corner designs are known, aiming at avoiding the drawbacks of the crib corners.

WO9730238 A1 discloses a joint structure comprising a post and joint elements in the post and in the log ends for joining them together. The joint elements consist of dovetail joints, by means of which the logs are joined and locked to the post. Moreover, the post comprises covering ledges overlapping the sides of the logs. The dovetail joints used in the structure are typically implemented by providing the log end with a tongue and the post with a groove. The structure can also be implemented in a converse manner, i.e. by providing the log end with a groove and the post with a tongue. WO9730238 A1 further discloses a groove both in the log end and in the post, in which case, when the log and post are aligned with each other, a double-tongued batten shaped to fit the space formed by the grooves can be inserted into the grooves, so that the wedge-shaped batten interlocks the logs and the post.

NO302905 B1 discloses a log structure in which the corner consists of a post with grooves to which tongues of ends of the logs are joined. The ends of lower and upper logs are extending through the post and are connected by regular cribbing, thus securing the post.

FR2880904A1 discloses a solution for building a shed, a bungalow, a chalet or a low wall. The solution provides wall sections made of spars connected to each using connections based on dovetail profiles. The wall sections are connectable by triangular elements that connect at a hypotenuse face. The triangular elements and the wall sections are connected using fastening elements such as bolts.

Publication US 5,277,008 discloses a building block which, in its operative position, comprises: a front and back surface, a top and bottom surface and two end surfaces; and a groove formed in both the top and bottom surfaces, the groove being shaped to receive a complementary-shaped key in a friction fit manner when one block is placed on top of another, wherein said block is generally parallelepiped in shape and has a cross-section such that the top surface and the front surface form an obtuse angle with one another.

A major drawback of the prior art is that the logs must enter the dovetail groove from the top of the erected post.

The invention has for its object to remedy or to reduce at least one of the drawbacks of the prior art, or at least provide a useful alternative to prior art.

The object is achieved through features, which are specified in the description below and in the claims that follow.

A log wall joint structure is provided, wherein adjoining end portions of log elements to be joined are each provided with a vertical groove. Thus, an end portion of an erected wall is forming a through groove extending from bottom to top of the wall, arranged to receive an edge portion of a first joining board. The corresponding groove of the opposing end portion of the adjacent wall is arranged to receive a second edge portion of the first joining board or an edge portion of a second joining board. A configuration of one or more joining boards forms a joining post with L-, T- or X- shaped cross sections arranged for the joining of two, three or four wall sections. The dimensions of the joining boards allow, when assembled, the joining boards to be interconnected, the connected joining board(s) forming a rigid and sealing joining post securing a corner or another connection of walls of a log wall structure. Preferably, each joining board is in one piece configured for extending between a lowermost log element to an uppermost log element of a wall section. However, it is also conceivable that each joining board may be made from two or more joining board pieces being stacked in series between the lowermost log element to the uppermost log element of the wall section. In such a stacked embodiment it is preferred that each joining board piece has a length being at least 2 times a hight of the log element.

In one embodiment an edge face of one of the assembled first and second joining boards bears against a lateral face of the other one of the first and second joining board. The joining boards are interconnected by fixing means, e.g. nails or screws, preferably releasable fixing means.

In one embodiment the exterior of the log wall joint structure is covered by one or more covering boards attached to the joining post and configured to overlap the outward facings of log end portions.

In one embodiment one or more pieces of first laths are attached along the outside of each joining board to form support for the covering boards. A thickness of the first laths being equal to the distance from the outward face of the joining board to the outward faces of the logs, thus filling the gap between the joining board and the exterior face of the wall. In an alternative embodiment, the covering boards are provided with protrusions extending inwards in a position of use. Such protrusions have the same purpose as said first laths, i.e., providing support for the covering boards and filling the gap between the joining board and the exterior face of the wall.

In one embodiment a second lath is attached along the inside of the joining post, filling the gap between the end portions of two adjacent log end portions. In an alternative embodiment, one of the joining boards is formed with a protrusion, so that joining board is formed as a single unit having an L-shape. The second lath discussed above is in this alternative embodiment superfluous.

Advantages of the invention are that a log wall joint structure according to the invention is easy to erect, it does neither require special expertise nor special on -site equipment. The log elements may be prefabricated.

The invention is defined by the independent patent claims. The dependent claims define advantageous embodiments of the invention.

In a first aspect of the invention, there is provided a log wall joint structure comprising wall sections made from stacked log elements, wherein end portions of adjoining wall sections are joined by a joining post. An end face of each one of the stacked log elements comprising an end face provided with a groove having a bottom, a mouth, and side faces extending between the bottom and the mouth, wherein a width of the bottom of the groove is equal to or less than a width of the mouth of the groove. The joining post is made from wood and comprises a first joining board interconnected with a second joining board, the first joining board configured for engaging the groove of a first wall section, and the second joining board is configured for engaging the groove of a second wall section. A thickness of each joining board is less than the width of the mouth of the groove, and a width of each joining board is so that a portion of the joining board is configured to protrude from the end face off the log elements when fully inserted in the grooves of the log elements, and longitudinal axis of the first wall section is non-parallel with a longitudinal axis of the second wall section.

The effect of the configuration of the groove and the joining board is that an edge portion of the joining board can be inserted from the mouth of the groove of stacked log elements towards the bottom of the groove after the log elements have been stacked. Thus, the joining board can be inserted perpendicularly with respect to a longitudinal axis of the groove in the wall section provided by the stacked log elements. This again has proved to be very effective in view of prior art wherein each log element must be threaded from a top of a post for providing a dovetail connection.

The joining post comprises as stated above, a first joining board interconnected with a second joining board, wherein the first joining board is configured for engaging the groove of a first wall section, and the second joining board is configured for engaging the groove of a second wall section, wherein a longitudinal axis of the first wall section is nonparallel with, for example perpendicular to, a longitudinal axis of the second wall section. Thus, in a log wall joint structure comprising a first wall section having an end portion for connection to an end portion of a second wall section, and the log wall joint structure comprises one or more intermediate sections interposed between the first wall section and the second wall section, the joining post may be inserted perpendicularly with respect to the groove of the wall sections.

Depending on the mutual orientation of the wall sections to be connected, the configuration of one or more joining boards forms the joining post with an L-, T- or X- shaped cross section arranged for the joining two, three or four wall sections, respectively.

At least one of the joining posts of the log wall joint structure may be provided by means of releasably interconnected joining boards. An effect of this is that the dismantling of the joining post for repair purposes or extension of a wall structure, is facilitated. However, the remaining posts made from at least two joining boards, may be interconnected by both mechanical fastening means and hardenable fastening means such as a glue.

In one embodiment is the side faces of the groove parallel. An effect of this is that the joining boards can be manufactured of standard timber with rectangular cross section.

In one embodiment is the thickness of the joining board equal to or less than the width of the bottom of the groove. This has the effect that the joining board can abut against the bottom of the groove. Thus, a protrusion of the joining board is defined by a depth of the groove and a width of the joining board.

An exterior of the log wall joint structure may be covered by one or more covering boards attached to the joining post and configured to overlap outward facings of log end portions. An effect of this is that the vulnerable end faces of the log elements are protected from rain and snow.

One or more first laths may be attached along an outside of each joining board forming support for one or more covering boards. An effect of this is that the attachment of the covering boards is more stable and durable.

A thickness of the first laths may be equal to a distance from an outward face of the joining board to outward facings of log end portions, thus filling the gap between the joining board and the exterior face of the wall section(s). An effect of this is that the stability and durability of the attachment of the covering boards are further improved.

The one or more covering boards may comprise two covering boards for providing a facing of a corner between two adjoining wall sections, wherein a portion of each covering board is provided with a protrusion adapted for abutting against a portion of the outward face of the post. An effect of the protrusion adapted for abutting against a portion of the outward face of the post, is that laths for filling the gap between the joining board and the exterior face of the wall section(s), may be superfluous.

In one embodiment is the protrusion configured for abutting against the end face of the log elements. This has the effect that the vulnerable end faces of the log elements are protected from rain and snow.

A further effect of said protrusion of the covering boards, are that the number of varieties of elements that may form part of the log wall joint structure is reduced, especially if the two covering boards are identical in form.

The covering boards provided with the protrusions may be provided with a wedge portion provided by a slanted abutment face mating with a recess forming part of the outwards facings provided in the end portion of the log elements. The slanted abutment face and the mating recess of the log element may be configured for providing a wedge connection providing a secure connection between the first wall section and a second wall section.

A second lath may be attached along the inside of the joining post, filling the gap between the end faces of two adjacent log end portions. An effect of this is that any gaps formed between opposite, adjacent log elements are firmly closed, causing improved sealing, and improved visual appearance of inward corners.

In one embodiment is the first joining board formed with a protrusion configured for filling the gap between the end faces of two adjacent log end portions. Providing the first joining board with such a protrusion has the effect that a separate, second lath is superfluous.

In a second aspect the invention there is provided a method for erecting a wall structure of stacked log elements by means of the log joint structure according to the first aspect of the invention, wherein the wall structure comprises a first wall section having an end portion adjoining an end portion of a second wall section and for being connected to the first wall section, and one or more intermediate sections interposed between the first wall section and the second wall section, wherein the method comprises the steps of:

a) aligning bottom log elements of at least two adjoining wall sections;

b) stacking a number of log elements for each of the at least two wall sections; and c) connecting at least the end portion of the first wall section with the end portion of the second wall section by inserting a second joining board into the groove of the second wall section and inserting a first joining board into the groove of the first wall section; and securing the first joining board to the second joining board to provide the post.

Preferably, the method comprises in step c) inserting the second joining board and the first joining board from the mouth of the grooves of the stacked second wall section and the stacked first wall section, respectively.

The method may comprise the further step of:

filling the inside gap between opposing log end faces of adjacent wall sections by second laths bearing against the log end faces. An effect of this is that any gaps formed between opposite, adjacent log elements are firmly closed, causing improved sealing, and improved visual appearance of inward corners.

The method may comprise the further steps of:

d) attaching several first laths to outward side(s) of the respective joining boards facing the exterior of the wall structure; and

e) attaching covering boards to the corresponding joining boards.

An effect of this is that the vulnerable end faces of the log elements are protected from rain and snow, the attachment of the covering boards being stable and durable.

An alternative method may comprise:

i) providing a log wall joint structure according to the first aspect of the invention; ii) erecting a first wall by stacking several log elements;

iii) stabilizing the first wall by interlocking the log elements by temporary engagement of a joining board with grooves at one end of said wall;

iv) engaging a joining post with the log end grooves at a free end of the first wall; v) erecting further adjacent one or more walls, allowing the adjacent groove of each log element to engage with the corresponding joining board of the joining post as the log elements forming the additional walls are stacked; and

vi) completing the wall structure by closing a final corner of the construction by entering the second joining board into the grooves of one of the opposite, adjacent walls, entering the first joining board into the grooves of the other one of the opposite, adjacent walls, and attaching the first joining board to the second joining board.

The invention also regards to a wall structure formed by several stacked log elements and comprising one or more log wall joint structures according to the first aspect of the invention.

In the following is described examples of preferred embodiments illustrated in the accompanying drawings, wherein:

Fig.1 shows in a perspective view of an assembly of a corner portion formed by a log wall joint structure according to the invention;

Fig.2 shows an embodiment of the wall joint structure, wherein the exterior of the wall joint structure is protected by covering boards extending along the corner joint;

Fig.3 shows an alternative of the wall joint structure, wherein a lath is filling the gap between the insides of two adjacent walls forming a corner;

Fig.4 shows a wall joint structure joining a cross wall and a longitudinal wall formed by two wall sections;

Fig.5a shows a top view of a corner portion of the log wall structure according to an alternative embodiment of the embodiment shown in fig.2; and

Fig.5b shows a section of the embodiment shown in fig.5a.

Any positional indications refer to the position shown in the figures.

In the figures, same or corresponding elements are indicated by same reference numerals. For clarity reasons, some elements may in some of the figures be without reference numerals.

A person skilled in the art will understand that the figures are just principal drawings that do not show complete wall joint structures. The relative proportions of individual elements may also be distorted.

In the figures, reference numeral 1 denotes a log wall joint structure, wherein a first wall section 111 and a second wall section 112 being formed by several stacked log elements 113, are joined by a joining post 12 engaging with vertical grooves 113c formed in the end faces 113b of the log elements 113. In the embodiment shown for example in fig.1, side faces 113d extending between a mouth at the end face 113b of the groove 113c and a bottom 113f of the groove 113c, are parallel, and a cross section of the grooves 113c are conform to the cross section of the portions of the joining post 12 arranged to enter the grooves 113c.

A first joining board 121 and a second joining board 122 are joined by an edge face 122a of the second joining board 122 facing away from the respective grooves 113c bearing against a lateral face 121a of the first joining board 121, thus forming the joining post 12. The joining boards 121, 122 are permanently or releasably interconnected by nails, screws, pins, glue, etc.

In fig.2, outward faces of the joining boards 121, 122 are identified by reference numerals 121c, 122c.

In the embodiments shown, the side faces 113d of the grooves 113c are, as mentioned above, parallel to allow the joining boards 121, 122 of the joining post 12 to be made with rectangular cross sections. A rectangular cross section of the joining boards 121, 122 is advantageous with respect to costs, since no special machining operation is required. However, in embodiments wherein the groove 113c in the end face 113b of each log element 113 is configured with a bottom 113f having a width being less than a width of the mouth of the groove 113c, joining boards 121, 122 having a non-rectangular cross section, may also be used so that the portion of the joining board inserted into the groove, fully mates with the groove.

Seal strips 128 are located between the stacked log elements 113 of each wall section. The seal strips 128 are typically secured to a top portion of each log element. Although not shown in the figures, it should be understood that the seal strips 128 extends between the end portions of each log element 113. In the embodiments shown, the top and bottom faces of the log elements 113 is profiled to inter alia improve the sealing of the wall sections 111, 112.

In what follows, methods of erecting a wall structure comprising a first wall section 111 having an end portion adjoining an end portion of a second wall section 112 and for being connected to the first wall section, and one or more intermediate sections (not shown) interposed between the first wall section 111 and the second wall section 112, will now be described. For a four-sided structure there will be two intermediate sections.

In a first method, a bottom log element 113 of each of the wall sections (for example four) are aligned and possibly secured with respect to a base such as a sill (not shown). Thereafter, a number of log elements 113 for each of the wall sections 111, 112 are stacked on top of each other to provide wall elements of a desired hight. To connect the adjoining end portions of the wall elements, a joining board 122 is inserted into the groove 113c of one of the wall sections 112, and a joining board 121 is inserted into the groove of the other one of the wall sections 111. Once inserted into their respective grooves 113c of the wall sections 111, 112, the joining boards 121, 122 are secured to each other to form the post 12. This operation is repeated until all wall sections (only two shown) are secured to each other.

In an alternative method, some, or all posts 12 apart from the final “closing” post, may be preassembled and brought into position of use while the wall sections are assembled. For example: A desired number of log elements 113 may be stacked to provide a first wall section 111. Once the first wall section111 is provided, a preassembled post 12 comprising a first joining board 111 and a second joining board 112, is connected to the groove 113c in one of the end portions of the first wall section 111. Thereafter, one log element 113 after the other is connected to the post 12 by displacing the groove 113c of each log element 113 into engagement with the post 12. This operation is carried out until the wall sections (for example the four wall sections) are completed. Connecting an end portion of a first wall section 111, with an adjoining end portion of a second (last) wall section 112, is explained in view of fig.1. Imagine that the first wall section 111 comprises a plurality of stacked log elements 113 providing a desired hight of the first wall section 111, and the second wall section 112 is the last one of four wall sections and comprises a plurality of stacked log elements 113 providing a desired hight of the second wall section 112. Imagine also that the post 12 is to be installed to interconnect the first wall section 111 with the second wall section 112. To provide the post 12, the second joining board 122 is inserted into the grooves 113c of the second wall section 112. The second joining board 122 is inserted with its longitudinal axis substantially perpendicular to a longitudinal axis of the stacked log elements 113. Thereafter, the first joining board 121 is inserted into the grooves of the first wall section 111. Thereafter, the first joining board 121 is secured or fastened to the second joining board at least by a mechanical fastening means, for example by screws.

To facilitate any dismantling of parts or all of a structure erected by means of the log wall joint structure 1 according to the invention, at least one of the joining posts 12 is made from joining boards 121, 122 releasably joined by nails, screws, etc. A dismantling of parts of the structure may be relevant with respect to repair or re-construction of the log wall joint structure 1, e.g., when a wall structure has to be extended by additional wall sections 111, 112. It should be noted that in for example a log wall structure 1 comprising four interconnected wall sections, only one of four joining posts 12, 12a may be releasably joined for example by screws. Once one of the four joining posts has been released from the grooves 113c of the stacked log elements 113, subsequent wall elements and joining posts may be dismantled. In view of fig.1, a start of such a dismantling may be as follows: after releasing for example screws connecting the first joining board 121 with the second joining board 122, the first joining board 121 is pulled out of the groove of the first wall section 111 made from a plurality of stacked log elements 113 (only one log element 113 shown). Thereafter, the second joining board 122 may be pulled out of the groove 113c of the second wall section 112 made from a plurality of stacked log elements 113 (only two log element 113 shown). Once the joining post 12 has been removed, each single log element 113 of the first wall section 111 and the second wall section 112 may be pulled out from the posts of the opposite ends of the wall sections 111, 112. Posts similar to the post 12 shown in fig.1, can be removed from the remaining stacked wall portions as one unit, i.e., without the joining boards forming the posts being separated.

An outward log end portion facing is identified by reference numeral 113e.

It is now referred to figure 2. To protect the log end portions 113a and the joining post 12, covering boards 124, 125 are attached to the joining post 12 covering the exterior of the joining post 12 and extending onto, i.e., overlapping, the outward facing 113e (see figure 1) of the end portions 113a of the log elements 113. Figure 2 depicts a portion of a protected corner of the wall structure. To facilitate the attachment of the covering boards 124, 125, one or more first laths 123 configured for providing support for the covering boards 124, 125are secured to the joining post 12. The laths 123 shown in fig.2 extend along the log end portions 113a and abut against the log end face 113b. Preferably, an outer face of the first lath(s) 123 is flush with said outward facing 113e of the end portions 113a of the log elements 113 of the respective wall sections 111, 112.

Figure 3 shows an inward corner formed by the log wall joint structure 1. A second lath 127 is placed at the inside corner of the joining post 12, bearing against the first and second joining boards 121, 122 and filling the gap between the inner portion of the log end face 113b and the facing joining board 121, 122. However, instead of filling the gap between the inner portion of the log end face 113b by means of a second lath 127 provided by a separate item, one of the joining boards 121, 122 may have been milled with an L-form having an “integrated” second lath 127’ as shown for example in fig.5a.

Referred now to figure 4. A cross wall 112 extends from a joint of a longitudinal wall 111 comprising a first wall section 111a and a second wall section 111b. A so-called extended joining post 12a interconnects the first and second wall sections 111a, 111b by the first joining board 121 that in one embodiment is wider than that of the joining post 12 forming a regular, single corner described above and depicted in figures 1-3. In such an embodiment, the second joining board 122 extends from the centre of the first joining board 121, engaging with the log elements 113 of the cross wall 112. The same configuration of the joining post 12 may be used if re-design of the log wall joint structure 1 depicted in figures 1-3 is required by extension of one or more walls. The regular joining post 12 according to figure 1-3 is dismantled and replaced by a suitable extended joining post 12a like a joining post with T-shaped cross section for joining three wall sections as depicted in figure 4 and even a joining post with X-shaped cross section (not shown) for the joining of four wall sections.

Still referring to fig.4. As an alternative to providing the first joining board 121 as a single board, the first joining board 121 may be provided by two joining boards 121 wherein a second joining board 122 is interposed between the two joining boards 121. A joining post 12a made in this way, allows the joining post 12a to be assembled after a plurality of log elements 113 has been stacked to form a log wall joint structure 1 comprising a first wall section 111a, a second wall section 111b, and a third wall section 112. This can be done as follows: inserting one of the two first joining board 121 into the grooves of one of the first wall section 111a and the second wall section 111b, and then inserting the other one of the two first joining board 121 into the grooves of the other one of the second wall section 111b and the first wall section 111a. Thereafter, the second joining board 122 is interposed between the protruding end portions of the first joining boards 121, and then urged into the grooves of the stacked log elements 113 of the third wall section 112. The joining boards 121, 122 are then secured to each other by means of for example screws to form the extended post 12a. The laths 127 shown in fig.4 are typically secured to the joining boards 121 before the joining boards are connected to their respective grooves, or the laths 127 form part of L-shaped first joining boards as discussed above.

Joining of only two wall sections 111a, 111b is possible by the use of an I-shaped joining post 12, i.e. a joining post 12 formed by one joining board 121 only, if a cross wall as depicted in figure 4 is not required.

Any covering boards 124, 125 as shown in fig.2, are attached to the corresponding joining posts 12, 12a, possibly after the attachment of the first laths 123 to external side(s) of the respective joining posts 12, 12a, providing support for the covering boards 124, 125.

Referring now to figures 5a and 5b showing an alternative embodiment of the covering boards 124, 125 shown in fig.2.

In figures 5a and 5b, more sophisticate or “tailor made” covering boards 124’ and 125’ are shown.

In the embodiment shown, the covering boards 124’ and 125’ are connected as a mitred corner. However, instead of being mitred as shown, the covering boards 124’ and 125’ may in an alternative embodiment be connected along the dotted line indicated through the left covering board 124’ abutting against an end portion of the log element 113 of the first wall section 111

Mitred covering boards 124’, 125’ are advantageous with respect to minimizing the number of varieties of elements that may form part of the log wall joint structure 1.

Independently of being mitred or not, the covering boards 124’, 125’ shown in figures 5a and 5b are provided with a slanted abutment face 114 mating with a recess 113’ forming part of the outwards facings 113e provided in the end portion 113a of the log elements 113. A depth of the recess 113’ in each log elements 113 decreases towards the end face 113b of the log element 113, so that when the covering boards 124’, 125’ have been secured to the post 12, the covering boards 124’, 125’ are wedged with respect to the log elements 113.

The embodiment shown in figures 5a and 5b makes the laths 123 shown in fig.2 superfluous, and thus represents a reduced number of operations required by an operator assembling the log wall joint structure 1 according to the invention. Since the log elements 113 can be premanufactured in a mill, the recess 113’ may be prepared when providing the groove 113c in the end portions of the log elements 113.

In figures 5a and 5b, the first joining board 121 is formed with a protrusion 127’. The first joining board 121 thus has an L-shape formed as a single unit. The second lath 127 shown as a separate item in for example fig.1, is therefore superfluous. It should be noted that the joining board shown in fig.5a, may also be used in the embodiments shown in figures 1 to 4.

Fig.5b further shown an example of how the covering boards 124’, 125’ can be secured to the post 12 only, and not the log elements 113, by means of mechanical fastening means, here shown as nails or screws 130.

The log wall joint structure 1 according to the invention allow the wall structure to freely shrink, as no fixing means connect the log elements 113 to the joining posts 12. Since there is no fixing means between the log elements 113 and the joining posts 12 other than sideway support provided by the side portions 113d of the grooves 113c, a wall section, for example an end wall secured to two side walls, may in theory tilt if subject to an outwardly directed force towards an inside of the end wall. To at least reduce such a risk, top portions of the wall sections may be interconnected to each other for example by means of an angle stell secured to the uppermost log elements 113 of the wall sections, at least until a roof and cornice boxing has been assembled. However, covering boards 124’, 125’ being wedged with respect to the log elements 113 as discussed above and shown in figures 5a and 5b, will prevent the risk of tilting and therefore make any additional interconnection by means of for example angle steel as mentioned above, superfluous.

From the above it should be clear that the present invention provides a log wall joint structure 1 that is easy and quick to erect, it does neither require special expertise nor special on-site equipment.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

Claims

C l a i m s

1. Log wall joint structure (1) comprising wall sections (111, 111a, 111b, 112), wherein end portions (113a) of adjoining wall sections are joined by a joining post (12, 12a), wherein the wall sections (111, 111a, 111b, 112) are made from stacked log elements (113), each one of the stacked log elements (113) comprising an end face (113b) provided with a groove (113c) having a bottom (113f), a mouth, and side faces (113d) extending between the bottom (113f) and the mouth, wherein a width of the bottom (113f) of the groove (113c) is equal to or less than a width of the mouth of the groove (113c),

c h a r a c t e r i s e d i n that :

- the joining post (12, 12a) is made from wood and comprises a first joining board (121) interconnected with a second joining board (122), the first joining board (121) configured for engaging the groove of a first wall section (111), and the second joining board (122) is configured for engaging the groove of a second wall section (112);

- a thickness of each joining board (121, 122) is less than the width of the mouth of the groove (113c); and

- a width of each joining board (121, 122) is so that a portion of the joining board (121, 122) is configured to protrude from the end face (113b) of the log elements (113) when fully inserted in the grooves (113c) of the log elements (113), and a longitudinal axis of the first wall section (111) is non-parallel with a longitudinal axis of the second wall section (112).

2. The log wall joint structure (1) according to claim 1, wherein an edge face (122a) of one of the assembled first and second joining boards bears against a lateral face (121a) of the other one of the first and second joining boards.

3. The log wall joint structure (1) according to claim 1 or 2, wherein the joining boards (121, 122) of the joining post (12) are releasably interconnected.

4. The log wall joint structure (1) according any one of claims 1-3, wherein side faces (113d) of the groove (113c) are parallel.

5. The log wall joint structure (1) according to any one of the preceding claims wherein a thickness of the joining board (121, 122) is equal to or less than the width of the bottom (113f) of the groove (113c).

6. The log wall joint structure (1) according to any one of the preceding claims, wherein an exterior of the log wall joint structure (1) is covered by one or more covering boards (124, 125; 124’, 125’) attached to the joining post (12) and configured to overlap outward facings (113e) of log end portions (113a).

7. The log wall joint structure (1) according to any one of the preceding claims, wherein one or more first laths (123) are attached along an outside of each joining board (121, 122) forming support for one or more covering boards (124, 125).

8. The log wall joint structure (1) according to claim 7, wherein a thickness of the first laths (123) is equal to a distance from an outward face (121c, 122c) of the joining board (121, 122) to outward facings (113e) of log end portions (113a), thus filling a gap between the joining board (121, 122) and the exterior face of the wall section(s) (111, 111a, 111b, 112).

9. The log wall joint structure (1) according to claim 6, wherein the one or more covering boards comprises two covering boards (124’, 125’) for providing a facing of a corner between two adjoining wall sections (111, 112), wherein a portion of each covering board (124’, 125’) is provided with a protrusion adapted for abutting against a portion of the outward face (121c, 122c) of the post (12).

10. The log wall joint structure (1) according to claim 9, wherein the covering boards (124’, 125’) are further provided with a wedge portion provided by a slanted abutment face (114) mating with a recess (113’) forming part of the outwards facings (113e) provided in the end portion (113a) of the log elements (113).

11. The log wall joint structure (1) according to any one of the preceding claims, wherein a second lath (127) is attached along the inside of the joining post (12), filling the gap between the end faces (113b) of two adjacent log end portions (113a).

12. Method for erecting a wall structure of stacked log elements (113) by means of the log joint structure (1) according to claim 1, the wall structure comprising a first wall section having an end portion adjoining an end portion of a second wall section and for being connected to the first wall section, and one or more intermediate sections interposed between the first wall section and the second wall section, c h a r a c t e r i s e d i n that the method comprises the steps of:

a) aligning bottom log elements (113) of at least two adjoining wall sections; b) stacking a number of log elements (113) for each of the at least two wall sections; and

c) connecting at least the end portion of the first wall section with the end portion of the second wall section by inserting a second joining board (122) into the groove (113d) of the second wall section (112) and inserting a first joining board (121) into the groove of the first wall section (111); and

securing the first joining board (121) to the second joining board (122) to provide the post (12).

13. The method according to claim 12, wherein step c) comprises inserting the second joining board (122) and the first joining board (121) from the mouth of the grooves of the stacked second wall section (112) and the stacked first wall section (111), respectively.

14. The method according to claim 12 or 13, wherein the method comprises the further step of:

filling the inside gap between opposing log end faces (113b) of adjacent wall sections (111, 111a, 111b, 112) by second laths (127) bearing against the log end faces (113b).

15. The method according to any one of claims 12-14, wherein the method comprises the further steps of:

d) attaching several first laths (123) to outward side(s) (121c,122c) of the respective joining boards (121, 122) facing the exterior of the wall structure; and e) attaching covering boards (124, 125) to the corresponding joining boards (121, 122).

16. A wall structure formed by several stacked log elements (113) and comprising one or more log wall joint structures (1) according to any one of claims 1-11.