This invention relates to the construction of log cabins, log buildings, and solid timber buildings and the like.
Solid wood buildings, made of logs or of squared timbers have been in use for centuries. A particular construction of solid wood building, commonly called “piece-en-piece” employs horizontal solid logs or horizontal squared timber members (or alternatively called herein “log members”) stacked vertically between upright timber members. The upper and lower elongated surfaces of each horizontal timber member are flattened. The main advantages of “piece-en-piece” construction is that a) it employs relatively short timbers which are easier to handle than wall-length logs, and b) short timbers of suitable cross-sectional dimensions are more abundant than long timbers of the same cross-sectional dimensions, and c) it requires relatively lower costs in labor, heavy equipment, and specialized skills than many other forms of log construction.
As currently practiced, piece-en-piece log construction requires that vertical tenons be fashioned into the ends of the horizontal log members that comprise a wall section. These tenons engage vertical mortises, or continuous grooves, that are cut into the faces of the upright timbers adjacent to the ends of the horizontal timber members. The mortise-and-tenon construction fulfils two functions: it secures the vertically stacked horizontal timbers from lateral movement, and it permits each horizontal log member to move vertically relative to the upright timbers as needed by shrinkage or settling forces. To set a horizontal log into place, it must be raised to the full height of the upright timber members in order to insert the tenons into the mortises of the upright timbers. Once the tenons are engaged into the mortises, the horizontal timber member is dropped down into position.
It was observed by the inventor that an opportunity exists to reduce manufacturing costs and labor costs for piece-en-piece log construction by means of an innovation in design.
The herein discussed examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.
The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
This invention reduces manufacturing costs and reduces labor costs for piece-en-piece log construction. Instead of fashioning vertical tenons into the ends of the horizontal log members, a vertical mortise, or groove is cut into each end. When the mortise in a horizontal log member is aligned with the vertical mortise in an upright timber member, the log is secured by inserting a spline into the matching grooves on the adjacent surfaces. Each spline extends below the lower surface of the horizontal log it is engaging, and into the mortise of the adjacent log below. The horizontal timber members are free to move vertically in response to shrinkage or settling forces. This method of securing the horizontal log members by means of matching mortises and splines is a reduction in manufacturing costs over fashioning tenons in the horizontal logs, and a mill need fashion but 3 components to build a wall or even a building: sills/tie beams, upright members, and horizontal member.
When assembling a wall, each horizontal log member is lifted no higher than is needed to insert it directly into place on top of a previously-laid log member. It is not necessary to lift each log to the full height of the upright timber members, as is the case with the typical mortise-and-tenon system. By these means, labor costs in assembling a wall are reduced, and the time of assembly is similarly reduced. As each log section is relatively short, two strong individuals can handle each piece, and no heavy equipment is needed to assemble the structure.
One or more strips of expanding weatherstrip insulation may be laid between adjacent upper and lower surfaces of the vertically stacked horizontal timber members. The elongated edges and the vertical edges of the horizontal timber members may be chamfered to accept a continuous bead of caulking or chinking sealant. The vertical edges of the upright timber members may be similarly chamfered to accept a continuous bead of caulking or chinking sealant.
Two upright timber members separated by vertically stacked horizontal timber members define a section of wall. A wall section is secured by attaching the lower distal end of each upright timber member to horizontal sill timbers which are attached to a foundation or floor construction. The tops of the upright timber members in a wall section are attached to each other with a tie beam, a horizontal timber member whose ends rest on the tops of each upright timber member and are attached to them. A succession of wall sections may be given lateral stability by fastening horizontal, a wooden top plate or doubled wooden top plates to the top of the tie beams so that they overlap the joints of adjacent tie beams.
In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.
Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive. The Figures show several perspective views of a wall section or a portion of a wall section, showing details of upright corner timbers and upright wall section timbers, horizontal timbers, mortises and splines, sill logs, tie beam logs, and top plates.
In drawings which illustrate preferred embodiments only of the present invention:
In both
Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
Tie beams 20 are fashioned in a similar or even identical manner as sill timbers 14, with notches creating half-lap joints with adjacent tie beams. Each tie beam joint rests on top of an upright timber member 10, 12. Each tie beam joint is preferably secured with a wooden dowel 18 or metal pin that extends into the distal end of the upright timber member on which it rests. One or more (preferably two) top plates 22 are secured to top surfaces of the tie beams. On walls that are comprised of a succession of wall sections, the top plates 22 will preferably span the entire length of the wall, or at least, the joints of each plate 22 will occur in the middle of a tie beam, and not over its joint. This strengthens the structure. The joints of upper and lower top plates will preferably be separated by the width of at least one wall section.
Horizontal timber members 24 are stacked vertically between upright timber members 10, 12. Their upper and lower bearing surfaces are preferably flat. The lowermost horizontal timber member 24 is preferably secured directly to the sill log member 14 on which it rests. A weather seal may be accomplished by placing two parallel rows of expanding foam weather strip lengthwise along the upper surface of each horizontal timber member. A vertical mortise 26 is cut into each distal end of each horizontal timber member 24. A vertical mortise 28 is cut into the vertical surface of each upright timber member where it faces the mortised distal end of a horizontal timber member 24.
A horizontal timber member 24 is set directly in place so that its mortises 26 face the mortises 28 on the adjacent upright timber members 10, 12. The horizontal timber member 24 is then preferably secured by inserting a wooden or metal spline 30 into the facing mortises, thereby generally locking horizontal timber member 24 laterally in place. Spline 30 may extend a short distance past the lower surface of the horizontal timber member 24 into the mortise of the horizontal timber 24 immediately below, securing those two members 24 together. Successive horizontal members 24 may be placed similarly, until a requisite height is obtained.
The longitudinal edges of the horizontal timbers may be chamfered ahead of time or after placement to accept a bead of caulking or synthetic chinking compound.
Tie beams 20 rest on top of the upright corner timber 10, their distal ends having been notched to create a right-angle half-lap joint. This joint is secured by a wooden dowel 18 or a metal pin which preferably extends into the top of the upright corner timber 10 on which the joint rests. A plurality of horizontal timber members 24 are stacked vertically on the sill timbers 14. The mortises at their distal ends are aligned with the mortise on the adjoining face of the upright corner timber 10 and are secured with splines as illustrated in
Horizontal timber members 24 are stacked vertically on top of the sill timbers 14. The distal ends of each horizontal timber member 24 have a vertical mortise (notated 26 in
To construct the structure 40, sill timbers 14 are usually first secured to the foundation, footings, or floor, establishing the perimeter of the building. As previously described, the distal ends of each sill timber are notched on opposite surfaces to provide for a half-lap joint 44 with adjoining sill timbers 14. A half-lap sill timber joint 44 may form a right-angle at corners, or may be in-line where it is in the middle of a wall 42. Again as previously described, each joint 44 is secured by a vertical wooden dowel or metal pin that extends through the joint and projects above it.
Upright timber members 10, 12 are positioned over each half-lap sill timber joint 44. Each upright timber 10, 12 has a cavity in the center of each distal end, preferably aligned with its longitudinal axis. The cavity in the lower distal end of the upright timber member 10, 12 accepts the dowel or metal pin projecting from the sill joint 44. Upright timber members 10 positioned over corners are mortised (preferably pre-mortised) on adjacent interior vertical faces (see
Horizontal timber members 24 are then stacked vertically on the sill logs 14. First, the lowermost timber 24 is secured to the sill log. Then, another timber 24 is placed on top of lowermost timber 24, and others are added in a similar manner. Each horizontal timber 24 has a vertical mortise on the centerline of each distal end. The mortises on each horizontal timber member are aligned with the vertical mortises of the adjacent upright timber members. These are secured with splines in the facing mortises as described in
When the required number of horizontal timber members have been positioned and secured with splines, tie beams 20 are positioned over each upright timber member 10, 12. The distal ends of each tie beam 20 are notched on opposite surfaces to provide for a half-lap joint 44 with adjoining tie beams. A half-lap tie beam joint 44 may form a right-angle at corners, or may be in-line where it is in the middle of a wall. The half-lap notch in each of the distal ends of each tie beam has a vertical hole centered in it to receive the dowel or metal pin projecting from the upright timber member.
When all tie beams 20 are secured in place, preferably two layers of top plates (not illustrated in
If settling or shrinkage occurs in the horizontal timber members 24, each horizontal timber member can move downwardly by gravity unimpeded by the mortise-and-spline system. In this instance, a gap will appear between the upper surface of the topmost horizontal timber member 24 in a wall section 100 and the lower surface of the tie beam above it. This gap can be easily filled with expandable foam weather sealing or the like and recaulked.
Traditional openings such as doors and windows can be added to the walls 42 either by cutting the timber members 24 after they have been put into place, or that shorter timber members 46 can be utilized to take into account the addition of a window, for example, as shown in
While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.
Number | Date | Country | Kind |
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2622773 | Feb 2008 | CA | national |