Log home
Encyclopedia
A log home is structurally identical to a log cabin
(a house typically made from logs
that have not been milled
into conventional lumber
). The term "log home" is preferred by most contemporary builders; a "log cabin" generally refers to a smaller, more rustic log house such as a hunting cabin in the woods.
Handcrafted log homes have been built for centuries in Scandinavia
, Russia
and Eastern Europe
, and were typically built using only an axe and knife. The Scandinavian settlers of New Sweden
brought the craft
to North America
in the early 18th century, where it was quickly adopted by other colonists and Native Americans
. Possibly the oldest surviving log house in the United States is the C. A. Nothnagle Log House
(circa 1640) in New Jersey.
During the 1920s the first milled log houses appeared on the market, using logs which were pre-cut and shaped rather than hand-hewn. Many log homes today are of the milled variety, mainly because they require less labor-intensive field work than handcrafted homes. There are about 500 companies in North America which build the handcrafted, scribe-fit type of log home.
Milled logs are processed in a different manner from handcrafted logs. Logs destined to become milled logs may become one of several types, depending on the desired quality and results.
is being measured. Green logs may have a moisture content ranging from about 20% to 90% (the oven-dry method of measuring MC).
One type of air-dried log is "dead standing," which refers to trees which have died from natural causes (bug kill, virus, fire etc.) and cut down after they died. Standing dead trees may be cut one month or several decades after they died, so the term "dead standing" does not necessarily mean the logs have dried down to equilibrium moisture content
. Dead standing logs can be green, or more-or-less dry.
After construction, green logs dry in service in the log building. Within about four years, green logs which are part of a completed log home reach equilibrium with local conditions and have an equilibrium moisture content (EMC) of between 6% and 12%. The actual EMC varies with local climate, season and location.
Once the logs have dried for the desired length of time, they are profiled and shipped to a customer. Profiling usually does not take place until shortly before shipment, to ensure that the logs stay as uniform as possible. It is uncertain whether this process is advantageous; it depends on many factors such as local climate, wood species, its size, and the location of the log structure.
Since logs reach equilibrium moisture content at about 6% and 12% (in North America); since most kiln-dried logs are dried down to about 18% to 20% moisture content kiln-dried logs can be expected to shrink and settle over time, but to a lesser extent than green logs. Common varieties of softwood lumber (such as framing lumber) are dried to a somewhat higher moisture content.
Depending on the type of glue and type of mill, there are two ways to finish the lamination process. One type of glue reacts with radio-frequency (RF) energy to cure the glue in minutes; the other uses a high-pressure clamp, which holds the newly-reassembled timbers under pressure for 24 hours. Once the glue has dried, the result is a "log cant" that is slightly larger than the buyer's desired profile. These log cants are run through a profiler, and the end result is a log that is perfectly straight and uniform. Some mills are capable of joining together small timbers by using a combination of face and edge gluing and a process known as finger- jointing. Boards which would be scrap at another mill may be used in the center of a laminated log or beam to minimize waste.
Nearly every profiled log on the market features an integral tongue and groove
milled into the top and bottom of the log; this aids in stacking, and eliminates the need for chinking.
Log homes which settle require slip joint
s over all window and door openings, adjustable jacks under vertical elements (such as columns and staircases) which must periodically be adjusted as the building settles, allowances in plumbing, wiring, and ducting runs, and fasteners for the walls themselves to prevent uplift.
Log cabin
A log cabin is a house built from logs. It is a fairly simple type of log house. A distinction should be drawn between the traditional meanings of "log cabin" and "log house." Historically most "Log cabins" were a simple one- or 1½-story structures, somewhat impermanent, and less finished or less...
(a house typically made from logs
Logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...
that have not been milled
Sawmill
A sawmill is a facility where logs are cut into boards.-Sawmill process:A sawmill's basic operation is much like those of hundreds of years ago; a log enters on one end and dimensional lumber exits on the other end....
into conventional lumber
Lumber
Lumber or timber is wood in any of its stages from felling through readiness for use as structural material for construction, or wood pulp for paper production....
). The term "log home" is preferred by most contemporary builders; a "log cabin" generally refers to a smaller, more rustic log house such as a hunting cabin in the woods.
Types
There are two types of log homes:- Handcrafted: Typically made of logs that have been peeled, but otherwise essentially unchanged from their original appearance as trees
- Milled (also called machine-profiled), made with a log house moulderLog house moulderA log house moulder is a machine to prepare logs to be suitable for building a log home. In general, the logs are first sawn to a square beam, then the moulder makes the groove. Often fitted to a portable sawmill that enables direct profiling of round or squared logs...
: Constructed of logs that have run through a manufacturing process which convert them into timbers which are consistent in size and appearance
Handcrafted log homes have been built for centuries in Scandinavia
Scandinavia
Scandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
and Eastern Europe
Eastern Europe
Eastern Europe is the eastern part of Europe. The term has widely disparate geopolitical, geographical, cultural and socioeconomic readings, which makes it highly context-dependent and even volatile, and there are "almost as many definitions of Eastern Europe as there are scholars of the region"...
, and were typically built using only an axe and knife. The Scandinavian settlers of New Sweden
New Sweden
New Sweden was a Swedish colony along the Delaware River on the Mid-Atlantic coast of North America from 1638 to 1655. Fort Christina, now in Wilmington, Delaware, was the first settlement. New Sweden included parts of the present-day American states of Delaware, New Jersey, and Pennsylvania....
brought the craft
Craft
A craft is a branch of a profession that requires some particular kind of skilled work. In historical sense, particularly as pertinent to the Medieval history and earlier, the term is usually applied towards people occupied in small-scale production of goods.-Development from the past until...
to North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
in the early 18th century, where it was quickly adopted by other colonists and Native Americans
Native Americans in the United States
Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...
. Possibly the oldest surviving log house in the United States is the C. A. Nothnagle Log House
C. A. Nothnagle Log House
C. A. Nothnagle Log House is a historic house on Swedesboro-Paulsboro Road in Gibbstown, New Jersey, near Swedesboro, that is one of the oldest surviving log houses in the United States....
(circa 1640) in New Jersey.
During the 1920s the first milled log houses appeared on the market, using logs which were pre-cut and shaped rather than hand-hewn. Many log homes today are of the milled variety, mainly because they require less labor-intensive field work than handcrafted homes. There are about 500 companies in North America which build the handcrafted, scribe-fit type of log home.
Components
The logs in log homes have a varying degree of moisture content; all logs have moisture when freshly cut. In the case of handcrafted logs moisture will naturally leave the timber, drying it out until it stabilizes with its climate. This drying-out causes movement and shrinking of the log's diameter. As logs and timbers dry, the differential shrinkage (radial versus tangential) causes small cracks (known as "checks") to open slowly over time. Checking is a natural process in both air- and kiln-dried logs. This occurs in all log homes regardless of construction method or how the timber is allowed to dry, and is considered normal.Milled logs are processed in a different manner from handcrafted logs. Logs destined to become milled logs may become one of several types, depending on the desired quality and results.
Green logs
Logs that are cut from the forest, brought to a mill or to a log-home construction yard, have their bark removed and are used to build a log-home shell (handcrafted log homes), or sent through profiling machines (manufactured logs) are usually referred to as "green" logs if they have not been air- or kiln-dried. "Green" does not refer to color, but to moisture content (MC). The actual moisture content of "green" logs varies considerably with tree species (cedar, fir, spruce, pine etc.), the season in which it was cut, and whether sapwood or heartwoodWood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
is being measured. Green logs may have a moisture content ranging from about 20% to 90% (the oven-dry method of measuring MC).
One type of air-dried log is "dead standing," which refers to trees which have died from natural causes (bug kill, virus, fire etc.) and cut down after they died. Standing dead trees may be cut one month or several decades after they died, so the term "dead standing" does not necessarily mean the logs have dried down to equilibrium moisture content
Equilibrium moisture content
The moisture content of wood below the fibre saturation point is a function of both relative humidity and temperature of surrounding air. The equilibrium moisture content is the moisture content at which the wood is neither gaining or losing moisture; this however, is a dynamic equilibrium and...
. Dead standing logs can be green, or more-or-less dry.
After construction, green logs dry in service in the log building. Within about four years, green logs which are part of a completed log home reach equilibrium with local conditions and have an equilibrium moisture content (EMC) of between 6% and 12%. The actual EMC varies with local climate, season and location.
Air-dried logs
Some log-home companies let the fresh-cut logs (or milled timbers) sit outside in the open air to dry naturally. The timbers can be stacked with spacers (known as "stickers") between them. This process allows the moisture content of the logs to naturally fall as the timber dries. It requires at least one year per inch of thickness, and requires adequate space to allow air circulation. If the logs are to be dried to equilibrium with the local climate the process may take several years, depending on the location and size of the timbers. In some environments, the logs must be kept under some type of roof or cover so that rain does not affect them.Once the logs have dried for the desired length of time, they are profiled and shipped to a customer. Profiling usually does not take place until shortly before shipment, to ensure that the logs stay as uniform as possible. It is uncertain whether this process is advantageous; it depends on many factors such as local climate, wood species, its size, and the location of the log structure.
Kiln-dried logs
Mills that have a kiln on site have the option of artificially accelerating the drying process. Green timber is placed inside a large oven, where heat removes moisture from them; however, they can suffer severe checking and cracking if the kiln controls are not properly monitored during the drying process. Use of a kiln can reduce the drying time from many months to several weeks. Kiln-drying usually results in an average moisture content of 18-20% ("average" means the average moisture content of the outside and the center of the log).Since logs reach equilibrium moisture content at about 6% and 12% (in North America); since most kiln-dried logs are dried down to about 18% to 20% moisture content kiln-dried logs can be expected to shrink and settle over time, but to a lesser extent than green logs. Common varieties of softwood lumber (such as framing lumber) are dried to a somewhat higher moisture content.
Glue-laminated timber
"Laminated" or "engineered" logs are a different approach to log-home building. Full trees or (alternatively) sawn cants (unfinished logs to be further processed) are brought to a mill with a dry kiln, the bark is removed and the trees are sawn into boards usually no more than two inches thick. These boards are then taken to the dry kiln, where (because of their size) they can be dried without causing severe damage to the wood. Timber destined for glue lamination must be brought down below 15% moisture before the lamination process will work, so typically these timbers are dried to around 8-10% moisture. The drying process varies on the species of lumber, but can be done in as little as a week. Once the drying process is complete the planks are sent through a surfacer (or planer), which makes the face of the lumber perfectly smooth. These planks travel to a machine, which then spreads a special glue on the interior boards.Depending on the type of glue and type of mill, there are two ways to finish the lamination process. One type of glue reacts with radio-frequency (RF) energy to cure the glue in minutes; the other uses a high-pressure clamp, which holds the newly-reassembled timbers under pressure for 24 hours. Once the glue has dried, the result is a "log cant" that is slightly larger than the buyer's desired profile. These log cants are run through a profiler, and the end result is a log that is perfectly straight and uniform. Some mills are capable of joining together small timbers by using a combination of face and edge gluing and a process known as finger- jointing. Boards which would be scrap at another mill may be used in the center of a laminated log or beam to minimize waste.
Types of milled logs
Milled-log homes employ a variety of profiles which are usually specified by the customer:- D-shape logs: round on the outside and flat inside
- Full-round logs: fully round inside and out
- Square logs: flat inside and out, and may be milled with a grooveGroove (joinery)In joinery, a groove is a slot or trench cut into a member which runs parallel to the grain. A groove is thus differentiated from a dado, which runs across the grain....
which could be chinked. When dealing with milled logs, chinking is a personal preference and not required to seal a home; however, a log home will eventually leak if it is not properly sealed. - Swedish Cope logs: round inside and out, with a half-moon-shaped groove on the bottom
Nearly every profiled log on the market features an integral tongue and groove
Tongue and groove
A strong joint, the tongue and groove joint is widely used for re-entrant angles. The effect of wood shrinkage is concealed when the joint is beaded or otherwise moulded...
milled into the top and bottom of the log; this aids in stacking, and eliminates the need for chinking.
Construction methods
- Scandinavian Full-Scribe (also known as the "chinkless method") is naturally-shaped, smoothly-peeled (drawknifeDrawknifeA drawknife is a traditional woodworking hand tool used to shape wood by removing shavings. It consists of a blade with a handle at each end. The blade is much longer than it is deep...
d) logs which are scribedCoping (joinery)Coping or scribing is the woodworking technique of shaping the end of a moulding or frame component to neatly fit the contours of an abutting member...
and custom-fitted to one another. They are notched where they overlap at the corners, and there are several ways to notch the logs. - In the flat-on-flat method, logs are flattened on the top and bottom and then stacked (usually with butt-and-pass corners).
- Milled log homes are constructed with a tongue-and-groove system which helps align one log to another and creates a system to seal out the elements.
- With the tight-pinned butt and pass method, the logs are not notched or milled in any way. They are in a single course and do not overlap; vertical pairs of logs are fastened with tight, load-bearing steel pins.
Corner styles
- Interlocking saddle notch: Normally seen on D- or full-round profiles, where a notch is cut into the top of one log and the bottom of another; these two logs then interlock, creating a tightly-sealed corner. Also popular in handcrafted, full-scribe log homes.
- Dovetail: Typically seen on square, hewn, or chink-style logs. A dovetail joint is cut on the end of a log, where it would rest in a corner—one to the right and one to the left; this creates a tight, interlocking corner. Handcrafted dovetails can be "full dovetail" (notch surface slopes in two directions simultaneously) or "half dovetail" (notch surface slopes in one direction).
- Butt-and-pass: Unscribed (or milled) logs butt up against each other at the corners without notching
- Saddle notch: Used where two round logs overlap each other near the corners; common with the Swedish cope profile
- Vertical corner post: Typically larger (e.g., 8" x 8") than the wall logs (e.g., 6" x 6"). The wall logs would be "toe nailed" into the corner post.
Other methods
- Half-Log: The structure is built with conventional building techniques, and "half-log" siding is applied to the exterior and interior walls to replicate the look of full-log construction. Some half-log sidings may also have saddle notch, butt-and-pass, or dovetail corners to give a more realistic appearance.
- Palisade style: The logs are standing on end, and are either pinned or bolted together.
- Piece en piece: Uses short logs (e.g. 8' long) lying horizontally between upright logs, resembling post-and-beamTimber framingTimber framing , or half-timbering, also called in North America "post-and-beam" construction, is the method of creating structures using heavy squared off and carefully fitted and joined timbers with joints secured by large wooden pegs . It is commonplace in large barns...
construction (but usually lacking the complex notching seen with post-and-beam). Piece en piece typically uses a large (8"x 8") vertical corner post. It is important that a vertical component (often 3"x 6") be placed on both sides of each window and door.
Settling
Once fabricated and assembled, the shell of the log home may be disassembled and the parts shipped to the building site. This allows for centralized manufacturing of the home, and relatively quick construction on site. Full-scribe-fit handcrafted log construction is a method of precisely marking where to cut each individual wall log to provide a tight fit between naturally-shaped logs along their entire length and in the corners. A high degree of craftsmanship is required for success in this method, and the resulting tight fit of naturally-shaped logs have aesthetic appeal.Log homes which settle require slip joint
Slip joint
A slip joint is a mechanical construction allowing extension and compression in a linear structure.-General forms:Slip joints can be designed to allow continuous relative motion of two components or it can allow an adjustment from one temporarily fixed position to another. Examples of the latter...
s over all window and door openings, adjustable jacks under vertical elements (such as columns and staircases) which must periodically be adjusted as the building settles, allowances in plumbing, wiring, and ducting runs, and fasteners for the walls themselves to prevent uplift.
See also
- BurdeiBurdeiA burdei, or bordei is a type of half-dugout shelter, somewhat between a sod house and a log cabin. This style is native to the Carpathian Mountains and forest steppes of eastern Europe.-Neolithic:...
- IzbaIzbaAn izba is a traditional Russian countryside dwelling. A type of log house, it forms the living quarters of a conventional Russian farmstead. It is generally built close to the road and inside a yard, which also encloses a kitchen garden, hayshed, and barn within a simple woven stick fence...
- Kit houseKit houseKit houses, also known as pre-cut houses, ready-cut houses, mail order homes, or catalog homes, were a type of prefabricated housing that was popular in the United States in the first half of the 20th century...
- Log cabinLog cabinA log cabin is a house built from logs. It is a fairly simple type of log house. A distinction should be drawn between the traditional meanings of "log cabin" and "log house." Historically most "Log cabins" were a simple one- or 1½-story structures, somewhat impermanent, and less finished or less...
- Magoffin County Pioneer Village and MuseumMagoffin County Pioneer Village and MuseumMagoffin County Pioneer Village and Museum is museum in downtown Salyersville, Kentucky that exhibits a collection of reconstructed log buildings from, mostly, the eastern region of Kentucky...
, Kentucky