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Green Timber
Logs that are cut from the forest, brought to a mill, cut to a profile and sold quickly are usually referred to as "green" or "wet" logs. These logs will have a very high moisture content sometimes upwards of 25%, which will cause massive shrinkage and cracking over a long period of time once the home is built.

Air Dried Timber
Some mills elect to let fresh cut logs sit outside in the open air to dry naturally. This process allows the moisture content of the logs to naturally come down as the timber dries. This process can take several months and requires the mill to have space to let the timber air out. Once the logs have dried for the desired time frame the logs are profiled and shipped to a customer. Profiling usually does not take place until right before shipment to ensure that the logs stay as uniform as possible. Air dried timber will settle much less than green timber, however, it will check and crack just as green timber would.

Kiln Dried Timber
Mill's that have an on-site kiln have the option of artificially accelerating the drying process. Green timber is placed inside a large oven where heat removes moisture from the logs much more quickly than does mother nature. Once profiled, Kiln-dried logs are even more stable with less shrinkage and settling than air-dried timber. Kiln-dried logs can suffer severe checking and cracking if moisture content is not properly monitored, but kiln drying can cut the drying time down from many months to a number of weeks, and usually results in average moisture content of 18-20%.

Glue Laminated Timber
"Laminated" or "engineered" logs are quite a different approach to log home building. Full trees are brought to a mill equipped with a drying kiln, the bark is removed and the trees are sawn into boards usually no thicker than two inches thick. These boards are then taken to the dry kiln where they, because of their size, can be dried without causing severe damage to the wood. The moisture content of timber which is destined for glue lamination must be brought down below 15% before the lamination process will even work, so, typically, these timbers are dried to around 8-10% moisture. The drying process varies with the species of lumber, but can be performed in as little as one 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 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 to cure the glue in a matter of 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 end result is what is called a "log cant" that is slightly larger than the buyers desired profile. These log cants are then run through a profiler resulting is a log that is perfectly straight and uniform.

The laminated or engineered log also has the lowest moisture content of any log on the market, and, since its moisture content is below the natural shrinkage level, it will not shrink, warp, or settle. Checking is reduced to an absolute minimum, which means it will not suffer from the large gaping cracks found in other log products.

Some mills are capable of joining together quite small timbers by using a combination of face and edge gluing and a process known as finger jointing. These boards which would be scrap to any other mill could be used in the center of a laminated log or beam to bring waste to a minimum.

In addition to being more consistent in size and appearance, milled logs can be found with varying degrees of moisture content, depending on the manufacturer and upon the desired end quality of the milled log.
[Citation: http://en.wikipedia.org/wiki/Log_home]

Milled Logs

Milled Log Homes have an assortment of profiles that are usually picked by the end customer. Just about every profiled log on the market today 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.

  • 'D' Shape Logs are round on the outside and flat on the inside.
  • Full round Logs are fully round on the inside and on the outside.
  • Square Logs are flat both on the inside and on the outside, and may be milled with a groove which could be chinked. When dealing with milled logs, chinking is more of a personal preference and is not required to seal the home. [Citation: http://en.wikipedia.org/wiki/Log_home]

Log Siding

  • Half-log siding is applied to exteriors to replicate the look of full-log construction; it can also be seen with false corners which give it a more realistic appearance. [Citation: http://en.wikipedia.org/wiki/Log_home]

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