Patent Publication Number: US-4649683-A

Title: Energy saving and endurance log for a log building

Description:
The invention relates to building logs for construction of log buildings and more particularly to a log construction which protects against moisture and provides added insulation for protection against the weather. 
     It is well known in the log building industry that logs are prepared by removing the bark and that the logs are usually laid upon one-another in a longitudinal superposed relationship. It is also well known that logs used have a great tendency to twist and shrink as the weather changes and or the logs dry out. Such twisting and shrinking usually causes cracks and openings to occur between the logs and or caulking used during the construction and in years to come. 
     It is therefore an object of the present invention to provide a log structure that prevents cracks to appear while drying out and during years to come. 
     Another object is to provide a log structure which prevents moisture from creeping between the logs as well as between the ends thereof which keeps the insulating materials dry. 
     Still another object is to provide a log structure that increases the insulation R-factor between the logs corners and the butt ends of the logs. 
     Yet another object is to provide means which adds strength to walls formed by logs and more positively relates the roof supports to the walls and foundation. 
    
    
     Other objects will become obvious and the invention will be better understood when related to the following drawings wherein: 
     FIG. 1 illustrates a pair of logs laid end-to-end without full weather protection features with a log structure thereon that shows even further weather protection elements in accordance with this invention. 
     FIG. 2 illustrates a splice block that joins two butt ends together with insulation between the butt ends shown. 
     FIG. 3 illustrates a side view of logs assembled on a foundation; 
     FIG. 4 illustrates an end view of the logs such as shown in FIG. 3; 
     FIG. 5 illustrates one wall surface as related to a &#34;ground&#34; floor; and 
     FIG. 6 illustrates a corner construction. 
    
    
     FIG. 1 illustrates three logs 10, 12 and 14 such as are assembled with their butt ends facing each other such as shown by logs 10 and 12 and with their lower and upper surfaces facing each other such as shown by logs 10 and 14. As shown more clearly by logs 10 and 14, the bottom surface of each log is formed to have a concave shape 16. The bottom concave surface by one log (14) is shaped to substantially conform with the upper surface of the log (10) upon which it is assembled. The butt ends of each log are provided with a central end slot 18 that extends from the upper surface down through the mid-point of the concave bottom surface. The length of each log is provided with a vertically extending longitudinal slot 20 which parallels the slot 18 into which a drip shield 22 is placed. The butt ends of each log are provided with arcuate grooves 24 near their outer surfaces which extend from adjacent to slot 18 down to longitudinal slot 20 such that the groove is to the outside of the drip shields 22. The circular section grooves 24 have placed therein thin plastic weather shields 26 which may be fixed in place by any suitable caulking to prevent any moisture from entering the butt ends when the logs (10 and 12) are assembled together. The bottom edge of the weather shields are outside of the drip shields 22. In order to provide further insulation, a strip of insulation 28 may be placed between the concave surface bottom of the upper log (14) and the upper surface of the adjacent lower log 10 as shown in FIG. 1. The insulation should extend along the length of the logs. 
     FIG. 2 illustrates a splice block 30 which is inserted into the slots 18 in adjacent butt ends when the logs are assembled. The butt ends of the logs are cut out to form a central circular section 32 inwardly of the drip shields into which poured foam 34 or any other type of caulking or insulation may be inserted between the butt ends with poured foam insulation around open space where splice block 30 has been set in giving strength and increasing the &#34;R&#34; factor at the butt splice. 
     The butt ends of log 10 has been shown with the slots 18, 20 and 24 therein without the splice block 30, drip shield 22, and the weather shield in place for clarification of the drawings. The drip shield and weather shield has been shown in the butt end of log 14 without designating the longitudinal slots 20 and end grooves 24. The splice block has been shown in place in FIG. 3. 
     FIGS. 3 and 4 illustrate a side view and an end view of a foundation 40 with a log 10 assembled onto the foundation. The sides and butt end of log 10 are provided with slots, grooves, drip shields and weather shields as set forth for the log 10 to protect its connection. 
     As shown in FIGS. 3 and 4, the logs are provided with vertically extending centerlined holes 44 into which a vertical support 46 is placed. The vertical support 46 is secured to the foundation at its bottom and the roof rafters 48 are secured to the upper end of the vertical support. The upper end of the vertical support is provided with a vertically extending linear slot 50 through which a bolt 52 connected to the roof rafter 48 may extend by which the roof rafter may be adjustable along the length of the slot. It is obvious that a plurality of such supports 46 will utilize the structure by tieing together the roof, walls and foundation. The vertical support adds strength to the walls and also aids in preventing twisting of the logs during drying during weather changes. 
     FIG. 4 further shows a longitudinal cut 54 along the length of the upper surface of the log which cut also relieves the stresses and strains of the log during drying and also helps prevents unsightly cracks elsewhere and acts as a barrier against heat or cold conduction. 
     It is to be noted that the weather shield extends down to the outside of the drip shield therefore any dripping from the weather at the butt joint will be to the outside of the drip shield. Therefore, the drip shield also protects the butt joint. The slots in which the drip shield are placed are wider horizontally than the drip shield so that the drip shield will be loose within the slot. The drip shield is applied, leaving a small space at the top of the slot in which it is inserted to leave room for shifting. Also, the splice block is loose in the slot in the butt end. Since these are loose in their slot, the looseness allows for twisting and shrinking during drying and weather changes. The edge of the drip shield that extends down over the surface of the adjacent log is secured thereto by rustproof nails, therefore, the upper edges of the drip shields are free to move within the slots 20 whereas the bottom edge is fixed to the adjacent log. Also, since there is space between the drip shield and the log, the space functions as additional insulation by forming an air pocket may also be used to run electrical wires. 
     Obviously, the drip shield can be placed on both sides of the log which will further add to the insulation factor. If one desired to add to the expense of building the log building, an insulation may be added between the drip shield and the log for additional insulation. The drip shield and weather shield will then protect whatever insulation is provided between the butt ends and between the drip shields and the logs. Not only do the drip shield and weather shields protect the logs against the weather, they also increase the R-factor of the insulation. 
     In assembly of the logs it is well known that the ends of the logs that form adjacent walls cross-over each other which interlock the ends of the logs. In order to cross-over each other at their ends, the bottom surface of each log at the surface of each log at the cross-overs is notched out to the mid-plane so that the bottom surface of an overlying log will have a close fit with the upper surface of the adjacent log. Further, in order to form walls that lie closely adjacent the foundation, two parallel walls must have a half-log 60 adjacent the foundation which allows the cross-over logs of the other two walls to cross-over the half-logs and to lie closely adjacent to the foundation. The exposed side of the half-log is provided with a slit 62 along its length in which a metal shield 64 is placed and which extends down over the foundation. 
     In construction of the log house, the &#34;ground&#34; floor 66 could be constructed on the foundation and the logs would be assembled above the &#34;ground&#34; floor construction on the foundation and the metal shield 64 would extend down over the floor and a portion of the foundation. 
     In order to increase the R-factor of the insulation, and to protect the insulation, plastic or any other suitable shields can be formed between the logs at their cross-over. Such shields will provide insulation and also prevent the rain and or snow from entering the area between the cross-over ends of the logs such as seen in FIG. 6. 
     The logs have been shown with a slit 54 along their top. This slit also extends out from the interlocking ends and is exposed to the weather. The exposed slits could be protected by a shield or poured foam which would prevent the weather from entering the slit. 
     The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.