Backcountry Notes

While it is possible to simply stack logs without notching the corners and thus make some sort of enclosure, such structures are neither stable nor durable.  Log cabin construction thus requires some sort of notching at the ends of the logs where they are to be stacked to form the corner joints of the "crib."

The Saddle Joint.  The Scotch-Irish immigrants learned the craft of log construction from settlers who brought the techniques with them from Sweden and Finland.  The Nordic cabin-builders used two very similar methods.  The simpler method is the saddle joint, which needed few tools and but a little practice; the more complex method, fully-scribed saddle joints, required more tools and greater skill and was not used in the Backcountry.  (Fully-scribed saddle joints bring the logs into full-length contact, eliminating the need for chinking.)

Saddle notches could be cut with only an axe, a mallet, and a chisel.  This substantially reduced the need to carry tools into the wilderness, which had great appeal to the Scotch-Irish who were moving rapidly into the Backcountry in the 18th century.  

Click on this image for a larger viewThe picture at left demonstrates saddle-joint construction. The ends of the logs are axe-cut, rather than sawn flat.  It is likely that more saddle-jointed cabins were built than any other kind; unfortunately, they were not durable, and even when they were kept for toolsheds or smokehouses or chicken coops they didn't last long.

There are purists who contend that only round-log structures should be called "log cabins," and cabins made with logs that have been dressed (squared off) should be called something else.  My own view is that we are dealing with vernacular architecture and the folk term "log cabin" has traditionally been applied to all forms of the genre - - so "log cabin" it is.

Pictured below is another example of round-log, saddle-joint construction. In this case, the ends of the logs have been sawn flat.  This building was (and is) used as a smithy; standards for such shop buildings were not as strict as those for residences in which settlers had to endure cold winter nights.

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The closeup view to the right shows why saddle-jointed cabins were not durable. As the logs dried, the joints tended to open up, admitting moisture which led to rot and insects. The joints then had to be filled with daubing but this typically only slowed the process of deterioration. 

Cabins built for recreation in the 20th century often used round-log, saddle-joint construction because it seemed more traditional. These structures can be properly treated with stains and preservatives and sealed with caulk, and thus are more durable.  Fully-scribed Nordic round-log construction is often used in modern log houses. 

Round logs were made from straight trees that had been felled and peeled of bark.  Most of the surviving cabins in Southern Appalachia were made with dressed timbers, that is, logs that have been squared off or cut into a rectangular cross-section.  If you examine the ends of such timbers, you should note that they are typically centered in the heart of the wood, or close to it.  Ideally, the diameter of the logs was only slightly more than a diagonal measurement through the size of timber wanted; this minimized the amount of cutting needed to dress the log.

Dovetail Joints.  Several varieties of dovetail joints were used in the Backcountry during colonial and early American times.  Dovetail joints are made using dressed logs and they have the advantage of making a joint which tends to tighten as the logs shrink, forming a more durable corner.  Dovetail joints require more skill and more tools than saddle-joints, but as the settlement of the Backcountry progressed, those skills and implements became increasingly available.  Dovetail-jointed cabins probably seem more numerous than they were because they are more likely to have survived into the present day.

One commonly seen form of dovetail joint employs the full-dovetail method of notching the end of a dressed log.  Full-dovetail notches are cut back at an angle, when viewed from the side, so that the top and bottom angle inward from the end of the log; and these cuts are also beveled, in the same manner that craftsmen use for making quality boxes and drawers.  The full-dovetail notch forms a tight joint that tends to resist separating as the wood dries. 

The cabin pictured below was built with full-dovetail joints.

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This is a closeup of dovetail joint construction.

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In this cabin under reconstruction, you can readily see the dovetail-joint method in use. 

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Another variation of the dovetail joint is called the half-dovetail. There are varieties of half-dovetails, but they all have in common the use of the dovetail notch on one side only, the other being left flat or being flat-notched.  Half-dovetails were often used for barns and outbuildings; as shown in the sketch at right, they were alternated with square-cut logs to place the notches top and bottom.  Maintaining chinking in such a construction would be tedious, but the method worked fine for corn cribs and the like.

Many surviving cabins use the half-dovetail method. Half-dovetails were used instead of full-dovetails by alternating the flat side to face up in one direction and down in the other, as in the building below.  Many surviving structures have a mix of full- and half-dovetail joints, possibly from having been rebuilt or repaired.

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This closeup gives an end view of half-dovetail joints. The logs running from left to right in the picture are oriented with the flat side up and the dovetail down; the logs seen end-on have the flat side down and the dovetail up.

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The Pike Joint.  Also called the V-notch and the steeple joint, the Pike joint is made by cutting a two-sided "steepled" bevel into the top of the log and an inverted "V" into the bottom, both cut at an angle which permits the inverted "V" to  fit snugly over the steepled top of the log below. The Pike joint apparently originated in Pennsylvania and then made its way south.  Because the shape of the Pike joint makes for a tight fit and tends to shed moisture, this joint is quite durable and accounts for a large proportion of surviving cabins.

The cabin pictured below is made with Pike joints (they are easier to see in the expanded view):

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The complex series of Pike joints on this cabin includes support for the porch roof overhang:

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Closeup view of a well-made Pike joint with flush-cut ends:

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Pike joint with extended ends:

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RELATED ARTICLES:

Log Cabins and Stone Buildings

Log Houses of Abingdon, Virginia

Crab Orchard Museum (picture gallery)

Copyright notice:  All text and images copyright 2009; do not use without permission.  The crude sketches are included, but if anyone is fool enough to want to use them, you have my blessing.