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diff --git a/59380-0.txt b/59380-0.txt new file mode 100644 index 0000000..30e0c95 --- /dev/null +++ b/59380-0.txt @@ -0,0 +1,1265 @@ +*** START OF THE PROJECT GUTENBERG EBOOK 59380 *** + + + + + + + + + + + + +Transcriber Note + +Text emphasis denoted by _Italics_ and =Bold.= Whole and fractional parts +of numbers as 12-3/4. + + + + + BUILDING + + with LOGS + + + + + Miscellaneous Publication No. 579 + + U. S. Department of Agriculture + + Forest Service + + +The art of log construction is relatively simple, once a few basic +principles are understood. The pioneers who opened the lands beyond the +eastern seaboard did not have boards with which to build such shelter as +they needed. Logs were so plentiful in the forested area of our country +that, with their resourceful ingenuity, the settlers built their homes in +conformity with those principles of log construction which prevailed in +the countries from which they migrated. Those principles have remained +the same down through the years. + +The pioneer had but an ax for a tool and consequently made only those +articles which could be hewed out of wood. Today there are many tools +available, and to do a first class job of log construction one must know +how to handle the double-bitted or single-bitted ax, the broadax, saw, +adz, chisel, slick, ship auger, and drawknife. In this bulletin it is +assumed that the reader is familiar with the ordinary frame building +methods used where wood is the principal construction material. + +Washington, D. C. Issued September 1945 + + + + +BUILDING WITH LOGS + + + +By Clyde P. Fickes, _Engineer_, and W. Ellis Groben, _Chief Architect, +Forest Service_ + + + + +Contents + + + Page + + Building the foundation 1 + Preparing the logs 1 + Dimensions of the building 2 + Framing the corners 3 + Round-notch corner 4 + Other log corners 7 + Door and window jambs 12 + Floor joists 12 + Laying the wall logs 12 + Window and door openings 14 + Window and door frames 16 + Roof framing 22 + Shake roofs 23 + Partitions 23 + Flooring 24 + Interior wood finishing 25 + Calking 25 + Chinking 27 + Chinkless log cabin construction 28 + Milled-log construction 31 + Hewing timbers 31 + Fireplace framing 31 + Oiling and painting 35 + The finished structure 35 + Furniture 39 + Chairs and stools 39 + Bed and bunk 39 + Chest and buffet 47 + Settee 47 + Dining table 49 + Table, bench, book rack, and wood hod 50 + Building plans 53 + Additional information 56 + + + +BUILDING THE FOUNDATION + + +A building should have a good foundation, and a log structure is no +exception to the rule. For the sake of economy in labor and material it +is sufficient, in some instances, to place small buildings on piers of +concrete or rough native stone, but usually it will be more satisfactory +to use continuous walls of stone masonry or concrete to provide +uninterrupted support for the logs and thus avoid their tendency to sag. +These walls, however, should be provided with small openings for the +circulation of air to prevent the wood from dry rotting. Furthermore, the +continuous foundation wall has the additional advantage of preventing +rodents from getting under the building. In no case should the logs be +placed directly upon the ground since wood tends to decay when in contact +with the earth. + +The two end walls of the exterior foundation should be higher than the +side walls in order to offset the difference in level of the logs on +adjacent walls, the end-wall logs being half their thickness higher than +those on the side walls. + +In building a log wall the chief problem is in closing the opening +between each pair of logs. There are various ways of doing this, but +only those regarded as most satisfactory will be described in this +publication. The width of such openings is affected by several factors: +(1) The manner of placing the logs upon each other; (2) the type of +corner used where two walls meet; (3) the openings for doors and windows; +and (4) the natural shrinkage of wood in the process of drying. + + + + +PREPARING THE LOGS + + +The selection of straight, smooth, even-sized logs is the prime +consideration (fig. 1). Top diameters should be as uniform as possible, +but as a rule not less than 10 nor more than 12 inches. (Slightly +smaller or larger dimensions may be used if no others are available.) The +taper should be as slight as possible. For logs longer than 40 feet, the +top diameter may be less than 10 inches in order to avoid an excessive +diameter at the large or butt end. + +[Illustration: Figure 1.--Starting to build the log cabin--laying the +foundation.] + +Cedar, pine, fir, and larch, in the order named, are most desirable +for log construction. All knots, limbs, or bumps should be trimmed off +carefully when the log is peeled. It is best to cut the logs in late fall +or winter, for two important reasons: (1) Logs cut in spring or summer +peel easier, but crack or check to an undesirable degree while seasoning. +(2) Insect activity is dormant during the winter months; hence, if the +logs are cut and seasoned then, they are less liable to damage by insects +or rot-producing fungi. + +Logs should be cut, peeled, and laid on skids well above the ground +for at least 6 months before being placed in the building. This may +not always be possible, but it is a good rule to follow. Logs should +be stored in a single deck with 2 or 3 inches between them to permit +complete exposure to the air. Logs having a sweep or curve should +be piled with the curve uppermost so that their weight will tend +to straighten them while they are drying. Where the skidding space +is limited, logs may be double-decked, using poles between tiers. +Unrestricted air circulation materially aids seasoning. + +Sort the logs carefully before starting construction, using the better +ones in the front or other conspicuous walls of the building. If the logs +are not uniform in size, the larger ones should be placed at the bottom +of the walls. + + + + +DIMENSIONS OF THE BUILDING + + +For practical reasons the dimensions of a log building are the inside +measurements taken from one log to the corresponding log in the opposite +wall. Outside dimensions vary somewhat with the size of the logs, thus +accounting for the use of inside measurements. Where projecting corners +are desired, logs should be at least 6 feet longer than the inside +dimensions of the building. In erecting the walls, the logs should be +kept even or plumb on the inside faces if it is desired to finish the +interior with wallboard or plaster. + + + + +FRAMING THE CORNERS + + +The corner is one of the most important aspects of log construction. On +it the appearance and stability of the structure depend. Different types +of corner construction are in use in the United States, each varying in +accordance with local building customs or individual taste. + +[Illustration: Figure 2.--The round-notch or saddle corner. This is +an unusually fine example of scribing and fitting logs together. The +square-cut logs have yet to be dressed and shaped with the ax to give +them a pleasing appearance.] + +[Illustration: Figure 3.--Ranger station, Gallatin National Forest, +Mont., illustrating effective use of round-notch corners. _A_, and _B_, +Dwelling under construction; _C_, barn.] + + +Round-Notch Corner + +The round-notch, or saddle, corner (fig. 2) is generally considered the +most satisfactory from every standpoint. This type of corner gives the +most distinctive appearance because the logs project sufficiently beyond +the corner not to appear dubbed off (fig. 3). It is a good, self-locking, +mechanical joint, relatively easy to construct, and holds the logs +rigidly in place. + +[Illustration: Figure 4.--Method of marking saddle corners.] + +In cutting the saddle, the material is taken out of the under side of the +upper log without disturbing the top surface of the bottom log. All the +moisture thus drains out at the corner and, consequently, the wood is +much less subject to decay than if other types of corners were used. The +shrinkage in the outer area of the log's circumference tends to open up +the space between the logs. Finally, in the round-notch corner, one-half +of the shrinkage between the logs is allowed to remain in the corner. The +separation, therefore, is not as great as if each log had been cut down +to the heartwood, a disadvantage common to most other types of corners. + +The tools required to make a round-notch or saddle corner are: A pair +of log dogs to hold the log in place, 10- or 12-inch wing dividers with +pencil holder and level-bubble attachment, sharp ax, 2-inch gouge chisel +with outside bevel, crosscut saw, spirit level, and plumb board. The +framing of this corner, described in figure 4, should be relatively easy. + +[Illustration: Figure 5.--Chopping the notch in a saddle corner.] + +First, the bottom logs should be set in place on opposite sides of the +foundation. Hew a flat face of 2 to 3 inches in width on the under side +of the log where it rests on the foundation, so that it will lay in +place. Then place the bottom log on each end-wall and accurately center +it so that the inside face of all four logs is to the exact interior +dimensions of the building. Dog the logs into place so they will not +move while being marked for the corner notch. The wing divider is now +set for one-half the diameter of the side log. With the lower leg of the +divider resting on the side of the under log and the other leg, with the +level-bubble uppermost, resting against the bottom of the upper log and +directly above the lower log, start moving the divider upward, with a +side motion, so that the lower leg follows the curvature of the under +log. The pencil point of the upper leg makes a mark on the surface of the +upper log which will be the intersection of the surfaces of the two logs +when the notch has been cut from the upper one. Repeat this operation +four times to mark all four sides of the corner. A little practice will +make you adept at keeping the points of the divider perpendicular to each +other. + +After the notch has been marked at both ends of the log, turn it over +on its back. It is a good idea to intensify the divider mark with an +indelible pencil so that it will be easily followed. Chop the notch +out roughly, as illustrated in figure 5, then chip down as closely as +possible to the mark, supplying the finishing touches with a gouge +chisel. The finished notch should be cupped out just enough to allow the +weight of the log to come on the outside edges, thus insuring a tight +joint. + +When the next side log is rolled into place, the dividers should be set +apart for the width of the space between the top of the first and the +bottom of the following log, and the marking repeated as before. If you +wish to have the upper log "ride" the lower one a little, so that an +especially tight joint is obtained, the dividers should be set a little +wider apart than the space actually requires. + + +Other Log Corners + +The dovetail, or box, corner (figs. 6 and 7) is a strong corner, and +considerable experience is required in order to make a neat-looking +job. This type has several undesirable features: (1) The logs are apt +to develop a wide crack because the corner is framed from the part of +the log in which the least shrinkage occurs, and (2) since the logs are +hewed down to form the corner, the wood has a tendency to collect and +retain moisture which soon results in decay. Also, this corner detracts +noticeably from the "loggy" appearance so characteristic and desirable in +log structures. The drawings in figure 6 show the most practical methods +of marking and framing the dovetail, or box, corner. + +The flat, or plain, tenon corner (fig. 8), is also common. It may be +made in two ways. In one, only the bearing surfaces are framed, while in +the other, all four sides of the tenon are framed flat. The plain tenon +corner does not have the highly desirable feature of being self-locking. +However, it is simple to make and economical, and therefore especially +suitable for temporary structures. The logs must be pinned together, as +shown in figure 11. All the framing can be done on the ground, before the +logs are put in place. Carefully fitted, this makes a neat-looking job. + +_Directions for constructing the flat, or plain, tenon corner._--Square +one end of log, as in figure 8, at point _A_, then measure required +length and saw the opposite end square, at _B_. If the log has any +curvature, turn it on the skids until its back is up. Determine the +thickness of the tenons, based upon the average top and butt diameters +of the log. Then take an 18-inch length of board the same width as the +thickness of the tenons, driving a nail through its center and into the +center of the log. Place the spirit level on top of the board and mark +lines on the log at the top and bottom edges. The width of a tenon +varies with the diameter of the logs; 8- to 10-inch diameters will +produce 6- to 7-inch wide tenons. + +[Illustration: Figure 6.--Marking and framing the dovetail, or box, +corner.] + +[Illustration: Figure 7.--Ranger Station, Lolo National Forest, Mont. +Note the meticulous construction of box corners.] + +[Illustration: Figure 8.--Framing the flat, or plain, tenon corner.] + +Nail a 1 inch by 1 inch cleat on the pattern board to points _C_ and _D_ +and then make saw cuts on each end, cut chip off and smooth the surface. +Turn log over and repeat on the other side. After framing out the sides +of the tenon, the log is ready to be placed on the wall. Some fitting +between corners is usually necessary but, if the logs are fairly straight +and smooth, the work will be minimized. + +The upright, or groove-and-tenon, corner (fig. 9) is used to a +considerable extent in the West. It has desirable features from a +mechanical standpoint: (1) The weight of the building is carried on +the full length of the logs and does not rest solely on the corners, +as in other types, and (2) it makes a tight wall because no openings +will develop between the logs. Although not difficult to construct, the +upright corner requires considerable mechanical skill and accuracy. +A good carpenter can frame the entire building on the ground before +any logs are placed on the foundation, after which it can be erected +in a very short time. Next to the round-notch corner the upright, or +groove-and-tenon corner, probably has the best appearance. + +[Illustration: Figure 9.--Framing the upright, or groove-and-tenon, +corner.] + + + + +DOOR AND WINDOW JAMBS + + +Door and window jambs should be framed just like the corners except that +only the back should be grooved. The door side, or face, may be rabbeted +or left smooth so that a separate wood door stop may be nailed in place. +If the logs are reasonably dry, from 3 to 4 inches should be left at each +corner for settlement due to shrinkage; otherwise, more or less space +should be allowed, as conditions require. In about 6 months the cap log +will come down and close this gap. Similar provisions should be made for +settlement over door and window openings. + + + + +FLOOR JOISTS + + +As soon as the first round or tier of logs is laid, the floor joists +should be set in place, notching them into the bottom side logs. If the +building has a continuous masonry foundation, the joists may be set on +top of it, as in a frame building. + +In order that the ends of the joists may have sufficient bearing on the +wall, it is necessary either to notch the ends into the side logs or +hew the latter off on the inside. A simple method is to cut the notches +in the side logs before they are rolled into place. Pole joists should +be from 4 to 8 inches in diameter and hewed level on the upper side to +provide a solid bearing for nailing the flooring. Several different ways +of framing the floor joists are shown in figure 10. + + + + +LAYING THE WALL LOGS + + +In laying the successive rounds of logs in the walls, several details +must be observed to keep them lined up so that the top logs form a +level seat for the roof framing. The corners should be kept as level as +possible as each round is laid. This can be done by measuring vertically +from the top of the floor joists, from time to time, as a check. A +variation of 1 inch in height will not cause a serious difficulty. + +The height of the corner's is regulated in two ways: (1) By increasing or +decreasing the depth of the notch, and (2) by reversing the top and butt +ends of the logs when laying them in the wall. + +The logs should be fitted together as tightly as possible. In the case +of somewhat irregularly surfaced logs, it may be necessary to smooth off +certain portions of the under side of the upper log to secure a tight +fit. Only in exceptional instances, however, should this be done to the +top of the lower log. + +The face of the logs on the inside of the building must be kept plumb, +that is, in the same vertical plane. An ordinary carpenter's, or spirit, +level may be used, but a 6- to 8-foot plumb board is considered most +satisfactory because of its greater length. + +The logs should be pinned together with a wooden pin or large spike (fig. +11). Spiking is done by boring a 3/4-inch hole halfway through the upper +log and continuing with a 7/16-inch hole through the bottom half. Then +drive a 10- or 12-inch spike into place, or until it penetrates half the +next log below. The spikes should be staggered in alternate rounds or +tiers of logs. If wooden pins are used, fir or oak logs are preferable. +Neither wooden pins nor spikes, however, offer interference to the +settling of the walls. + +[Illustration: Figure 10.--Framing floor joists.] + +The spike method is easier and quicker, and just as satisfactory as +the wooden pin. The logs should be pinned approximately 2 feet from +each corner and at each side of the window and door openings. For small +structures, where the alignment of the walls is not so important, pinning +may be eliminated, but it is essential to align larger buildings +accurately in order to prevent individual logs from springing out of +place. + +[Illustration: Figure 11.--Pinning logs together.] + +Where the use of logs having a decided curve, or sweep, is unavoidable +they should be set in the wall with the bow or back up. Such logs may +be straightened by making enough saw cuts in the upper side of the +curved surface to allow them to straighten out. The cuts should be +from one-third to one-half the depth of the log, or slightly more, if +necessary (fig. 12). + +[Illustration: Figure 12.--Straightening a curved log.] + + + + +WINDOW AND DOOR OPENINGS + + +Early American log structures were characterized by relatively dark +interiors because window openings, designed for protective purposes, +were small and far apart. Since protection is no longer a consideration, +window frames may be of standard size and located where they are most +suitable for adequate day lighting. + +As soon as the first round of logs and the floor joists are laid in +place, mark the location of door and window openings on the inside face. +Next saw out the door openings and chop out the notch in the doorsill log +to within an inch of the true or finished line, as shown in figure 13. +Leave final cutting of the openings to the exact dimensions until the +window and door frames are to be placed in position, thus insuring a good +finished wood surface. Also, determine the height of the openings above +the floor line and mark them in figures on the bottom log for reference +from time to time. The necessary cuts should be made in the log directly +over each opening before placing it in position. When the log which +carries the window frame is reached, a notch must be made for it as for +the doors. + +[Illustration: Figure 13.--Cutting window and door openings.] + +To provide the necessary doors and windows, openings must be cut in the +walls after the logs have been placed in position. As soon as a log in +the wall is cut in two, the problem arises of how to hold the loose ends +in place. Also, the doors and windows require the proper kind of frames +to insure airtight closure between the latter and the ends of the wall +logs. The most practicable and satisfactory method is to frame a vertical +notch in the ends of the wall logs, into which can be fitted a spline +attached to the back of the jamb or side-pieces of the door and window +frames. This method of framing holds the wall logs in place, allows them +to shrink and settle without hindrance, and makes a weathertight joint +between them and the door and window frames. The vertical notch in the +end of the wall logs may be framed by boring a 2-inch auger hole in each +log as it is laid in place. The hole should be located so that, when the +wall logs are sawed out for the opening, the saw cut passes down through +the edge of the hole nearest the opening. It is then a simple matter to +frame the notch to take the spline. The inside face of the notch can be +left rounded and the spline chamfered to fit. To keep the holes in line +from log to log, use the plumb board illustrated in figure 14. + +[Illustration: Figure 14.--Method of marking openings.] + + + + +WINDOW AND DOOR FRAMES + + +There are two ways of making window and door frames--in three pieces +(two side jambs and one head jamb), or in four pieces (two side jambs, +one head jamb, and a sill piece). When a three-piece frame is used, the +bottom log of the opening is cut or shaped to make the window or doorsill +and the jamb pieces are then fitted to the sill. If the jambs are framed +from pieces of log slabbed on two opposite sides, a presentable frame in +keeping with the log character of the structure is obtained. The window +or door face of the jamb pieces may be rabbeted for the windows and +doors, respectively, or they may have separate wooden pieces, known as +stops, nailed on. The spline on the back of the jamb may be rabbeted out, +or a 2 inch by 2 inch piece of straight-grained wood nailed on. The head +jamb can be framed in the same way; it does not require a spline on the +back. Each side jamb has a dowel framed on each end. The bottom dowel +fits into a mortise in the sill and the top dowel into a similar mortise +in the head jamb. + +[Illustration: Figure 15.--Window frames.] + +In a four-piece frame, the sill log is cut with a slope, in the customary +way, and the jambs are fitted as for a three-piece frame. Figure 15 +illustrates the installation of three- and four-piece window frames. + +When the head jamb or top log over the opening is reached, the frames are +ready for installation. The opening is now cut out, the sill fashioned, +the vertical spline slot framed, and the head jamb log cut out to fit +over the opening. At this point, the amount of settlement resulting from +the shrinkage of the wall logs, as they dry out, must be determined and a +corresponding allowance provided in the opening. This allowance is made +between the upper side of the headpiece of the frame and the bottom of +the log directly over the opening, and should be from 2-1/2 to 4 inches +for a door 6 feet 8 inches to 7 feet in height, or 1-1/2 to 3 inches +for an ordinary double hung window. The log over the opening should be +notched out on the under side so that it can be dropped in place after +the frame has been set in position. + +When the type of window or door frame here described is used, neither +outside nor inside casings, sometimes called wood trim, are required. The +logs selected for the jamb material should be from 2 to 3 inches larger +in diameter than the wall logs, in order to fit properly. Also, they will +be much easier to work if well-seasoned (fig. 16). + +[Illustration: Figure 16.--Log jamb window frame.] + +[Illustration: Figure 17.--Typical log-wall section, taken through +window.] + +If standard mill work frames are used, false side jambs of sawed +material, usually 2-inch planks, should be fitted in the openings to hold +the logs in place. For a wall made of 10-inch logs, a plank 2 inches by +10 inches should be used for the jambs and the standard frame fitted in +place between them after providing the necessary allowance for the wall +logs to shrink or settle. The head casing ordinarily will cover the space +allowed for shrinkage. + +Some kind of insulating material which will take compression, such as +crumpled newspapers, asbestos wool fiber, or rock wool, may be used to +fill the space over the head allowed for settlement. Insulating material +must be installed loosely, so as not to take any weight as the headlog +gradually settles. + +[Illustration: Figure 18.--Various ways of framing eaves. Despite the +fact that sawed rafters, as shown above, are often used for convenience +in framing the roof, sawed or milled material is incongruous in +appearance in the exterior of log buildings Hence, pole rafters, +hand-made shakes, and similar hand-riven features are preferred.] + +For the log-type frame, copper or galvanized steel flashing should be +fastened to the bottom of the cut in the top log, leaving the lower edge +of the flashing free to slide on the face of the log head jamb. As the +wall settles, the bottom of the flashing can be trimmed off if too much +of the face of the head jamb is covered. This makes a weathertight joint +and protects the insulating material with which the shrinkage space has +been filled. See figure 17, Head section. + +[Illustration: Figure 19.--Framing log purlins for shakes.] + + + + +ROOF FRAMING + + +Roofs may be framed in several ways, depending upon the kind of material +available and the appearance desired. The framing for a shingle roof, +whether of sawed material or round poles, is done in the same way as that +of a frame building. The top log on the wall may be cut with a flat seat +for the rafters to rest upon, as at _Y_, in figure 18, _A_ or notched out +to receive them as at _Z_ in figure 18, _B_. The gable ends may be run +up with the logs, which is preferable for architectural appearance, or +framed like the gables of a frame structure, and then covered with wood +siding, shingles, or shakes (fig. 19). + +The shingles may be laid over sheathing boards in the usual manner or on +shingle strips placed across the roof rafters, parallel with the ridge +and exactly spaced to receive them, commonly known as "barn-fashion." + +The particular method to be followed in framing the eaves depends largely +upon their projection. Where the effect of a considerable overhang is +desired, an eave purlin log may be used to support the projecting shakes +as shown in figure 19, _A_. To support 30- to 36-inch long shakes having +a 6-inch lap, the log purlins should be spaced at approximately 24-inch +intervals, as in figure 19. In regions of heavy snows, the eave log may +be placed slightly forward to help support the overhang, or an additional +eave log may be placed in position, as shown in figure 19, _B_. The gable +logs should be run up at the same time as the roof logs, and both rigidly +framed together. + +[Illustration: Figure 20.--Splitting shakes with the froe.] + + + + +Shake Roofs + +It is often desirable to use hand-split shakes for the roof covering. +These are usually made from cedar, but may be of any straight-grained +wood, free from knots, which splits easily. First, the logs are cut in +lengths of 30 to 36 inches and then the shakes are split off with a tool +called a froe (fig. 20). + +After the log cuts are set on end, the froe is held on the upper end of +the block and then struck a blow with a wooden maul which causes a piece +of the block or shake to split off. Being hand-split, the thickness +varies somewhat; the minimum is 1/2 inch. A roof of thin shingles, +lacking sufficient scale, is never as effective as a rough textured one, +using 3/4- to 1-1/4-inch thick shakes, to harmonize with the sturdy +appearance of the log walls. The width, normally 6 to 8 inches, is +governed by the size of the blocks of wood and varies accordingly, while +the length is governed by the spacing of the roof logs or purlins. Shakes +are always laid on the purlins in single courses, lapping the sides 1-1/2 +to 2 inches and over-lapping the ends at least 6 inches, as illustrated +in figure 19. Nailing is usually done with six- or eight-penny galvanized +box nails. Copper nails may be used for greater permanence. A good shake +roof will not leak although from the inside of the building it may appear +to have many holes. + +The ordinary, uninteresting, straight-line effect at the butts may +be broken up by staggering them from 1 to 2 inches, as is often done +with shingles. This method produces an effect more in keeping with the +log walls. Although involving greater care and additional labor it is +preferable, from an architectural point of view, to the more common +custom of laying them to uniformly straight lines. + +At the ridge of the roof, where the shingles or shakes intersect, +provisions must be made for weatherproofing. The shingled Boston ridge, +comb intersection, or pole ridge, shown in figure 21 are practical and +much more satisfactory from the standpoint of architectural effect than +stock metal ridges, ridge boards, and other methods. + +[Illustration: Figure 21.--Ridge treatments.] + + +PARTITIONS + + +If the log building is to be divided into several rooms, at least two +different methods may be used to construct the partition walls. If the +log construction plan is to be carried throughout the structure by using +interior log-wall partitions, these should be laid out and framed in, +and the door openings cut in the same manner as previously described for +exterior walls. If a log partition comes at a place in a cross wall where +it is not considered desirable to have the log ends project into the room +beyond the opposite face of the wall, they may be sawed off flush with +the face of the cross wall, as shown at _X_, figure 22, Plan _A_. This +will not weaken the joint since the logs are both pinned and locked in +place. + +[Illustration: Figure 22.--Interior partitions.] + +Where frame partitions are used, they should be constructed as in a frame +building. A gain or a 3- to 4-inch deep groove should be cut in the log +wall into which the end studding of the frame partition is to be set +(fig. 22, Plan _B_). The cut should be made in each log before it is +placed in the wall. In no case should the studding at the ends of the +partitions be nailed to the log walls which they intersect in order not +to interfere with or be affected by their shrinkage and settlement. + + + + +FLOORING + + +A subfloor should be laid first using shiplap or sheathing. Over this a +finished floor of such hardwoods as maple or oak, or the harder softwood +species such as Douglas-fir, western larch, or southern pine, may be +laid. Vertical grain and flat grain may be had in both softwood and +hardwood, but the vertical grain shrinks and swells less than the flat, +is more uniform in texture, wears more evenly, and the joints open much +less. Finished flooring consists or tongue-and-groove material of various +thicknesses and widths. + +Despite a slight tendency to splinter and wear irregularly over a period +of years, plain wide planking of random-width boards makes an appropriate +floor for a log building. An attractive effect may be had by using screws +instead of nails, countersunk to a depth of 1/2 inch and concealed by +inserting false wooden dowels glued in place as shown in figure 23, _B_. +Keying the boards together with wood keys, at random along the edges, +adds to the attractiveness of the flooring. + + + + +INTERIOR WOOD FINISHING + + +Hanging doors and windows, and many other customary details of building +construction should be done in the usual manner in building with logs. +Whenever cupboards or other built-in units are constructed, they must +be framed to be independent or entirely free of the log walls, like the +furniture. However, such fixtures as lavatories may be attached to two +adjacent logs without any subsequent structural complications. + +[Illustration: Figure 23.--Flooring. _A_, Plain tongue and groove; _B_, +random-width planking.] + + + + +CALKING + + +When round logs are laid up in a wall there is always an opening between +them unless they are grooved on the under side to saddle the one below, +as described later under chinkless log cabin construction. In exterior +walls, this opening, or crack, must be closed in order to make the +structure weathertight. There are several methods of doing this. If +the logs are reasonably straight and uniform in size and the corners +carefully made, the opening between them will be small, often barely +perceptible. When this is the case, the openings should be filled with +some sort of calking compound applied with either a pressure gun or a +trowel (fig. 24). + +[Illustration: Figure 24.--Examples of tight joints well calked. _A_, +Interior calking; _B_, exterior calking.] + +In recent years several kinds of calking material have been put on the +market. They are applied best with a gun having a pressure-release +trigger whereby the calking compound is forced through a nozzle made in +various shapes and sizes to meet different requirements. These calking +compounds are not adversely affected by heat or cold, retain their +natural flexibility, and have an adhesive property which causes them to +adhere to the surface to which they are applied. + +A good plastic compound will adhere to the logs under all conditions +and can be patched easily by simply applying more material. A black +fiber seal is not objectionable and, at the same time, gives a practical +finish. The seal should be applied to both sides of the exterior and +interior log walls, producing an almost hermetically sealed building. +When applied with a pressure gun having a 3/8-inch nozzle, 1 gallon will +fill about 300 linear feet of opening. If applied in cold weather, the +material should be heated to a temperature of 60°F. + + + + +CHINKING + + +When using logs that are somewhat rough and irregular in shape, the +resulting space between them may be so large that the calking material +cannot be used satisfactorily to fill the opening. In such cases, it +will be necessary to insert "chinking," which usually is applied to the +interior and exterior walls in one of two ways: + +1. _Split chinking._--Segments of a log are split out in sizes which fit +the opening and, after being carefully shaped with the ax to make a tight +fit, are securely nailed in position. This kind of chinking requires +considerable work and patience to secure a good appearance. + +2. _Pole chinking._--Small round poles may be used to fill the openings +(fig. 25). Usually they are cut in sizes and lengths to fill the opening +from wall to wall. This sort of chinking may be applied rapidly to either +inside or outside walls and makes a neater job than the preceding method. +Unless the logs are thoroughly seasoned these small poles sometimes +have a tendency to pull away from the nails. When the chinking has been +completed, the openings will have been reduced sufficiently in width to +allow the calking material to be applied successfully. + +[Illustration: Figure 25.--Pole chinking.] + +It is always a serious problem in log construction to devise a practical +method for permanently fastening the plaster daubing in place on both +inside and outside walls. In some instances, shingle nails may be driven +into the logs 2 to 3 inches apart for the full length of the opening or +2-inch wide strips of metal lath may be used and the plaster applied to +fill it. Cattle hair may be added to the plaster to increase its adhesive +consistency and thereby hold it more rigidly in place. Sometimes, wood +strips are nailed on the lower log to hold the plaster in position, as +shown in figure 26, but they are unsightly. + +[Illustration: Figure 26.--Wood daubing strips.] + + + + +CHINKLESS LOG CABIN CONSTRUCTION + + +Chinkless construction, associated with the building of log structures in +Scandinavian countries, eliminates the chinking and mudding so prevalent +in many log buildings. It consists of grooving the under side of every +log in each tier so that it saddles the log beneath, making a close +joint for its entire length. The groove is marked by a tool which, for +convenience, may be called a cabin scribe or a drag (fig. 27). + +_Directions for chinkless log cabin construction._---Mark and cut out +the notch just as is done for a round-notch corner. Next, dog the log in +place and scribe, making the additional mark shown by dash line (_X_, +fig. 27). Then, cut to line and, finally, drop log in position. + +The scribe is 12 inches long, made preferably of 3/8-inch square steel +or iron bent in much the same manner as the spring in a steel trap; the +two ends are turned down about 1-1/2 inches like two fingers, diverging +to about 3/4 of an inch at the points, and then sharpened with a flat +surface on the inside of the point toward the loop. The loop should be +hammered out thin to provide sufficient flexibility to allow the points +to spread or close easily. A ring is welded around the two halves of the +tool which, when slipped up or down, makes it possible to adjust the +points and thereby prevent any further spreading while the tool is in +use. A link from a small chain, placed over the legs before the points +are turned, will serve the same purpose and, to prevent the points from +springing together, a small piece of wood may be forced between them. + +[Illustration: Figure 27.--Chinkless log cabin construction.] + +To fit a log, first frame it at the ends and then fit it down to within +about 2 inches of the lower log where the opening is the widest It is +difficult to do a good job of scribing when the logs are too close +together. The scribe must then be adjusted at the point where the +opening is the widest so that, when holding the tool parallel to the +opening, the lower point of the scribe will ride on the surface of the +bottom log. By exerting sufficient pressure, the upper point will score +the top log. Repeat this operation to score the upper log on the other +side. The corner tenons must be marked likewise. Next, turn the log over, +work the tenons down and then cut a =V=-shaped groove to the marked lines +in the remaining portion of the log, using a double-bitted ax. This +groove should be cut deep enough along its center to permit the outer +edge of the groove to rest continuously on the lower log. By removing the +least amount of wood to make the smallest possible groove, the closest +fit is obtained with the least effort. + +[Illustration: Figure 28.--Fine example of milled-log +construction--ranger's dwelling, Whitman National Forest, Oreg.] + +The principle of the scribe is based on parallel lines, and it can +readily be seen that if there is a hump on the lower log there will +have to be a gouge in the upper one. When the work is done carefully, +the space remaining is negligible. Where an airtight wall is desired, +a strip of plumber's oakum should be laid on the bottom log before the +upper log is dropped into place. If this material is not available, dry +moss is a fairly practical substitute. + + +Milled-Log Construction + +Sometimes it is feasible to take advantage of a portable mill to face the +logs on three sides rather than to hew them by hand. The level beds seat +the logs so well that calking is minimized, the smooth interior surfaces +permit of easy finishing, particularly where wood wainscoting or plaster +is used, while the round-log exterior effect is undisturbed, except where +the logs project at the corners. Figure 28 illustrates a structure built +in this way. + + + + +HEWING TIMBERS + + +The facing or hewing of round timbers to obtain one or two sides surfaced +flat for framing purposes, as shown in figure 29, requires considerable +skill in the use of the ax and broadax. There are, however, a number of +mechanical aids (fig. 30) which should be used by anyone undertaking +log construction in order to simplify the work as much as possible. The +carpenter's spirit level, the steel square, and chalk line and chalk are +necessary for laying off the lines to be followed in hewing timbers. In +framing logs they should be laid up on skids, or sawhorses, dogged fast +in place with iron dogs, and the dimensions laid off on each end of the +log with the level and square to insure that the lines are parallel to +each other. Then, with the chalk line, carefully snap lines on the side +of the log connecting corresponding points at each end. For squaring the +ends of a log and cutting pole rafters, use the miter box to guide the +saw. To measure lengths accurately the steel tape, or a board pattern cut +to the exact length, may be used. + + + + +FIREPLACE FRAMING + + +The living-room fireplace, invariably the most prominent interior +feature, harmonizes best with a log interior if built of stone and +provided with a crude log shelf. The fireplace itself may be either the +traditional masonry type or the more modern metal-lined one equipped with +a heatilator. + +The masonry of the fireplace and its chimney should always start on +solid earth, below the frost line, like the foundations of the building +itself. Masonry does not settle, unlike the surrounding log construction. +Consequently, it is recommended that a self-supporting log framing be +built around and entirely free of the masonry of the fireplace and +chimney, as illustrated in figure 31. The opening should be framed in +the same way as window and door openings. The fireplace and chimney +masonry should not be erected until the opening has been framed for it. +Upon completion, the intersection between the stone and wood should be +thoroughly calked to make an airtight, weatherproof job. This method +allows the wall logs to settle, because of the unavoidable shrinkage, +without structural failure. + +[Illustration: Figure 29.--Framing hewed timbers.] + +[Illustration: Figure 30.--Mechanical aids in cutting timbers. Method: +Cut both miter boxes at angle _X_ for 1/3 pitch. Fasten them securely to +the floor or to a log, used as a sawhorse, and space exactly the required +distance apart to insure that all rafters are cut alike. Then place each +rafter in the boxes, back down if any curvature exists, dog rigidly in +place and saw to the pattern. + +Line A represents the exterior wall face and, if sawed off on line _B_, +parallel with the wall face, overhang of eave will be 1 foot, 6 inches. +Any desired overhang may be had and sawing eliminated by fixing the +distance _C_. The irregularly hewed rafter end is preferable to the +uniform elliptical saw-cut ends. Finally, hew the upper surface of the +rafters to a smooth even bearing to receive the roof sheathing boards.] + +[Illustration: Figure 31.--Framing around the fireplace. Framing logs +around fireplace and chimney varies with the effect desired: (1) By using +an exposed vertical slabbed log and spline, as at _A_, with space _X_, to +allow for the shrinkage settling of the logs above the mantel, or (2) by +using a concealed vertical slabbed log and spline, as at _B_, where the +masonry is exposed above the mantel.] + +[Illustration: Figure 32.--A useful type of modern log dwelling--ranger +station, Gallatin National Forest, Mont.] + +In building an ordinary fireplace, the firebox and inner hearth should +be made of firebrick to withstand intense heat and the various parts +proportioned in accordance with standard practice to insure efficient +operation.[1] + +[1] For this purpose the following publication will be found useful: +Farmers' Bulletin 1889, Fireplaces and Chimneys. + +The heatilator is a built-in recirculating steel unit consisting of metal +sides and back to form a heating chamber, adjacent to the fire pit, which +draws cold air through a register at each side near the floor and after +the air is heated ejects it through similar registers above. It should be +installed in conformity with the manufacturer's directions, taking care +to select a stock-size unit suitable for the dimensions of the fireplace +opening and to erect the surrounding masonry accordingly. + + + + +OILING AND PAINTING + + +After all the openings have been properly calked and the logs brushed +clean, it is often desirable, although not absolutely necessary, to treat +the log surfaces with some sort of preservative material. Logwood oil is +excellent for the exterior. The colorless variety is preferable in most +cases but, if some color is desired, add just enough burnt umber, or raw +sienna paste, to give the proper shade. For interior finish, apply a coat +of clear shellac and then one or two coats of dull varnish. The trim can +be treated in a similar manner to preserve the pleasing effect produced +by the natural surface and color of the wood. + + + + +THE FINISHED STRUCTURE + + +Examples of modern log construction are shown in figures 32, 33, and 34. +Early types of log structures are illustrated in figure 35. + +[Illustration: Figure 33.--Modern structures showing effective use of log +construction in recreation buildings on national forests in Montana. _A_, +Dude ranch; _B_ and _C_, recreational and mess hall, Seely Lake.] + +[Illustration: Figure 34.--Organization camp at Seely Lake showing log +work In greater detail. _A_, Entrance wing; _B_, cabin group. Note the +wedges under porch post to provide for settling of walls. Wedges are +gradually driven out as necessary.] + +[Illustration: Figure 35.--Early types of log structures built by the U. +S. Forest Service in the West. _A_, Ranger station, Gallatin National +Forest, Mont.; _B_, ranger's dwelling, Nezperce National Forest, Idaho; +_C_, log cabin in Arizona.] + + + + +FURNITURE + + +The matter of interior furnishings is always of great concern to those +who build log cabins. Odds and ends or too many "what-nots" may prove +to be misfits. Pieces of Early American design are perhaps the most +appropriate ready-made furniture, but sturdy, rustic pieces yield the +greatest satisfaction. + +Many cabin owners have found a great deal of pleasure in making essential +furniture, such as bunks, beds, tables, chairs, settees, and similar +items. In the East, birch is preferred as a material, and in the West, +lodgepole pine is most satisfactory. Other native species, however, +will do just as well. In making furniture it is advisable to remove +the bark from the logs because bark collects insects, causes the wood +to deteriorate and eventually falls off, leaving imperfect, unsightly +surfaces. Figures 36 and 37 show types of furniture suitable for log +residences. + +For rustic effects, the use of a stain of the following proportions gives +a satisfactory appearance: 2 quarts turpentine, 2 quarts raw linseed oil, +and 1 pint liquid drier, to which add 1/2 pint of raw sienna, 1/2 pint +of burnt umber, and a touch of burnt sienna. The top surfaces of tables, +buffets, chests, and rawhide seats should have two coats of spar varnish. +Where countersunk screws are used in connection with a stain finish, +insert false wood, dowel-like plugs in preference to plastic wood to +conceal the screwheads. + +Simplicity, both in construction and appearance, is the keynote for +producing the most harmonious effects in furniture, in keeping with log +interiors. + + +Chairs and Stools + +Armchairs can be built with well-seasoned lodgepole or eastern pine, or +birch (fig. 38). The cornerpieces should be mortised and tenoned to the +frame and rail and anchored in place with 3/8- by 15-inch lag screws. The +arms should be fastened to the cornerpieces with 3/8- by 5-inch carriage +bolts and to the slab support with 3/8- by 4-inch lag screws. The +vertical slab support should be rigidly secured to the frame with 3/8- +by 3-inch carriage bolts. Cushions may be of the filler type, without +springs, and covered with homespun fabric. Use 2-inch wide heavy canvas +strips, securely fastened with furniture tacks, to support the cushions. + +Upright chairs and stools (fig. 39) can be made from the same material as +the armchair. Cross the poles to impale the legs rigidly. The crosspieces +of the chair back should be curved to fit the human back. The joints must +be tightly glued, mortised, and tenoned. + +[Illustration: Figure 36.--Furniture suitable for log cabins--convenient, +sturdy, and easy to make. _A_, Bed; _B_, bed and armchair.] + +[Illustration: Figure 37.--_A_, Dining table appropriate for log cabin; +_B_, book rack and hod.] + +[Illustration: Figure 38.--Plan for making an armchair suitable for log +residence.] + +[Illustration: Figure 39.--Plan for making an upright chair and stool.] + +[Illustration: Figure 40.--Plan for making a double bed for log +residence.] + + +Bed and Bunk + +Birch or well-seasoned lodgepole or eastern pine is suitable for making +a bed or bunk. In making a bed (fig. 40) the crosspieces should impale +the corner posts tightly; the joints should be glued and toe-nailed from +below. Do not cut the side or end pieces until the bedspring has been +measured and then allow for a slight play in both directions in setting +the angle irons, in order to facilitate the insertion and removal of the +mattress. Use 14- by 3-inch carriage bolts to fasten the angle irons +to the wood frame. Figure 40 is a plan for making a double bed 5 for a +single bed, reduce the width accordingly. + +A double-deck bunk is made in much the same way as a bed (fig. 41). + +[Illustration: Figure 41.--Plan for building a double-deck bunk.] + +[Illustration: Figure 42.--Plan for making a combination chest and +buffet.] + + +Chest and Buffet + +No log residence is complete without furniture for storing clothes. A +combination chest and buffet suitable for log cabins can be made from +well-seasoned lodgepole or eastern pine, tamarack, or birch (fig. 42). +The ends, doors, shelves, and drawer fronts should be cut from No. 2 +tongue-and-groove commercial pine lumber. + + +Settee + +A settee can be made from well-seasoned pine or birch (fig. 43). Join the +corner poles to the slab frame and rail with mortise-and-tenon joints; +then anchor the joints by means of 3/8- by 6 -inch lag screws. Fasten the +arms to the corner poles with 3/8- by 5-inch carriage bolts and to the +slab support with 3/8- by 4-inch lag screws. Use 3/8- by 3-inch carriage +bolts to fasten the slab support to the frame. The 1- by 2-inch hardwood +crosspieces should be securely fastened at the top ends and notched into +the legs at the bottom ends, held by 2-inch wood screws, driven into +place at an angle. Back slats should be mortised and tenoned to the rail +and frame. The cushions should be the filler type, without springs if so +desired, and covered with homespun fabric. + +[Illustration: Figure 43.--Plan for making a living-room settee.] + +[Illustration: Figure 44.--Dining table plan.] + +[Illustration: Figure 45.--Plan for making benches.] + + +Dining Table + +Peeled pine or birch is ideal material for building a dining table (fig. +44). Make a tight saddle joint between _B_ and the legs. Cross poles to +impale the legs tightly. Notch _E_ for the cross poles. Upper surface +of _C_ should be slab-faced and fitted between _D_ and cross poles, all +rigidly braced together. Top pieces of tables should be doweled at places +indicated in the drawing with 1/2- by 4-inch wood dowels, glued and +clamped to insure tight joints. Notch top pieces A 1-inch deep to receive +_B_ and _D_. Top outside edges of _A_, _C,_ and _E_ should be hewed. + +[Illustration: Figure 46.--Plan for a book rack.] + + +Table, Bench, Book Rack, and Wood Hod + +Well-seasoned lodgepole or eastern pine, tamarack, cedar, or birch are +suitable for benches (fig. 45). The joints should be glued. Countersink +any screws, then conceal the heads with false wooden dowel-like plugs. +If the furniture is to be painted, use plastic wood. A book rack may be +made of the same material used for the bench, except cedar, which is +unsuitable (fig. 46). The sides and bottom shelf should be rabbeted and +thoroughly glued. The two intermediate shelves can be made adjustable by +boring 3 holes in each side-piece 2 inches apart, above and below the +position shown for the shelves in figure 46, into which loose wooden pins +may be inserted for their support. Screw the top in place, countersink +screwheads and insert wood cover plugs or false dowels for concealment +where stained finish is used. If painted, plastic wood may be used. + +[Illustration: Figure 47.--Plan for a fireplace wood hod.] + +A fireplace wood hod (fig. 47) may be made of wood and metal. Use +well-seasoned lodgepole or eastern pine, tamarack, or birch. Make a tight +cradle joint between horizontal and vertical side-pieces, using 14- by +2-inch carriage bolts except that by 3-inch lag screws should be used +for fastening the lower side-pieces and bottom. Secure the wrought-iron +handle to each side toppiece with 3- by 1-1/2-inch carriage bolts. The +wood sides should have hewed edges of 3/4 inch minimum thickness. + +[Illustration: Figure 48.--Floor plan for a four-room log residence.] + + + + +BUILDING PLANS + + +Selection of the site and preparation of building plans varies with +individual taste. In choosing a location one must consider availability +of transportation, shopping centers, water supply, sewage disposal, +electric facilities, and kindred factors. + +[Illustration: Figure 49.--Floor plan for a four-room log residence with +somewhat different orientation than that shown in figure 48.] + +Before undertaking construction it may be desirable to consult an +architect or competent builder to make sure that (1) your desires are +satisfied with respect to the necessary accommodations; (2) rules and +regulations enforced by local authorities will be observed; and (3) +provisions are made for installing telephone, electricity, water, and +plumbing facilities. Failure to take these precautions may necessitate +costly changes after construction has begun. + +Plans for suitable four-room log residences are given in figures 48 and +49, and for a five-room structure in figure 50. Figure 51 shows the +layout of a United States Forest Service two-room guard cabin adaptable +for summer residence use. + +[Illustration: Figure 50.--Floor plan for a five-room log residence, +including three bedrooms, living-room, kitchen, and two porches.] + +[Illustration: Figure 51.--U. S. Forest Service two-room fireguard cabin +adaptable for summer residence use.] + + +ADDITIONAL INFORMATION + + +Additional useful information on building log cabins may be obtained from +the following publications: + + +UNITED STATES DEPARTMENT OF AGRICULTURE + +FIREPLACES AND CHIMNEYS. Farmers' Bul. 1889, 52 pp., illus. 1940. + +PROTECTION OF LOG CABINS, RUSTIC WORK, AND UNSEASONED WOOD FROM INJURIOUS +INSECTS. Farmers' Bul. 1582, 20 pp., illus. 1929. + +USE OF LOGS AND POLES IN FARM CONSTRUCTION. Farmers' Bul. 1660, 26 pp., +illus. 1931. + + +OTHER SOURCES + +LOG BUILDINGS. Wis. Agr. Col. Ext. Stencil Cir. 158, 39 pp., illus. 1940. + +LOG CABIN CONSTRUCTION. A. B. Bowman. Mich. State Col. Ext. Bul. 222, 54 +pp., illus. 1941. + +LOG CABINS AND COTTAGES; HOW TO BUILD AND FURNISH THEM. W. A. Bruette, +ed. 96 pp., illus. New York. + +THE REAL LOG CABIN. C. D. Aldrich. 278 pp., illus. 1934. New York. + +SHELTERS, SHACKS, AND SHANTIES. D. C. Beard. 243 pp., illus 1932. New +York. + + + + U. S. GOVERNMENT PRINTING OFFICE: 1954 + + + + For sale by the Superintendent of Documents, + U. S. Government Printing Office + + Washington 25, D. C. -- Price 25 cents + + * * * * * + + +TO KEEP THE TREES GROWING + +Here in the United States we are cutting trees faster than new ones are +growing for the future. And because science is showing us how to use wood +better and in new ways we are likely to want more trees in the future +than we use today. In fact we must double the annual growth of usable +wood. This can't be done easily or quickly. It will require decades of +good forestry. So we must take steps now-- + + To protect all our forests well from fire, insects, and disease; + + To stop wasteful and destructive cutting; + + To keep plenty of trees of all sizes growing to replace those we cut; + + To restore commercial tree growth on millions of acres of forests + that have been badly treated or burned; + + To give farmers and other small owners more help in growing, + harvesting, and marketing their tree crops; + + To put wild land into public forests when private owners cannot take + care of it or the public interest calls for special treatment. + + + * * * * * + + +Transcriber Notes + + +All illustrations were moved so as to not split paragraphs. + + + + + + + + +End of the Project Gutenberg EBook of USDA Miscellaneous Publication No. +579: Building with Logs, by Clyde P. Fickes + +*** END OF THE PROJECT GUTENBERG EBOOK 59380 *** |