Read Ebook: Delineations of the Ox Tribe: The Natural History of Bulls Bisons and Buffaloes. Exhibiting all the Known Species and the More Remarkable Varieties of the Genus Bos. by Vasey George

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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: The manner of placing the logs upon each other; the type of corner used where two walls meet; the openings for doors and windows; and 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 . Top diameters should be as uniform as possible, but as a rule not less than 10 nor more than 12 inches. 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.

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: Logs cut in spring or summer peel easier, but crack or check to an undesirable degree while seasoning. 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.

Round-Notch Corner

The round-notch, or saddle, corner 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 . It is a good, self-locking, mechanical joint, relatively easy to construct, and holds the logs rigidly in place.

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.

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 is a strong corner, and considerable experience is required in order to make a neat-looking job. This type has several undesirable features: 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 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 , 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.

The upright, or groove-and-tenon, corner is used to a considerable extent in the West. It has desirable features from a mechanical standpoint: 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 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.

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 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 . 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.

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.

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 .

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.

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.

WINDOW AND DOOR FRAMES

There are two ways of making window and door frames--in three pieces , or in four pieces . 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.

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 .

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.

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.

ROOF FRAMING

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