The Germanic tribes were semi-migratory people. The developments BC were a transition from hunter-gather to farming communities. However, these communities could not be permanent over a period of generations, because the people did not understand the importance of replenishing soil nutrients, so as a result they would over time deplete their farms, and have to move on to new lands.

The Germanic tribes in particular moved a lot, and underwent long periods of migration, most notably the early medieval Great Migration, where tribes systematically moved in and picked apart the remnants of the Western Roman Empire -establishing Germanic dynasties in the previously Roman territories of France, Britain, Switzerland, Spain, and even Italy. Another example being the Viking Age.

This all ended when the monasteries introduced a new farming practice, crop rotation. They introduced the 3 field system, and so Germanic farming communities suddenly became permanent.

As far as descent from Roman tradition, I would love to agree with that, but everything I have read claims that is not so, at least not to a very high degree. IT is generally agreed that he Roman techniques were lost and building across western europe reverted to post building for a few centuries. As far as I can tell, roman techniques are thought to have only survived in roof framing.

The half timbered design is shown to be descended from post building, with an intermediate style with posts set on stones and an externally braced frame, similar to the Norse langhús
[img[http://upload.wikimedia.org/wikipedia/commons/d/dd/Fyrkat_hus_stor.jpg[/img]

which leads to styles similar to the alpine Ständerbohlenbau or Scandinavian Stavverk, which seems to lead off in 2 directions. This style ultimately develops in some regions to half timbering, essentially the wood panels are replaced with stone or brick or some such. In other regions, the posts are eliminated and the style becomes log building. It is believed that both half timbering and log building are developed from the post built house.

I dont think it would not be entirely accurate to categorize Ständerbohlenbau as Fachwerk, and I don't think that the Germans do, as the word is generally intended to refer to a half timbered structure. But it is an important step in the development of the style.

I had found a Swiss website once with information on Ständerbohlenbau and historical development, but I don't know if I will be able to find it again.

What would be ideal is if there is something as simple as the tiny book "Historic American Timber Joinery: A Graphic Guide" by Jack Sobon that shows pictures of joinery types and where to use them. As of now I am not seeing enough detail to fully understand how a structure is put together and with only sketchy German resources it is unrealistic to contemplate a build based on it.

And is it spelled Allemanic or Alemannic? Google doesn't like the former spelling.

then probably the latter spelling! due to the fact that the German form is Alemannisch. The Germanic tribe can be referred to as Alamanni, Allemanni, or Alemanni.

http://www.modellbau-quedlinburg.de/mbq/cms/front_content.php?idcat=142

that website has all of the joints used, but doesn't tell you exactly how they are used. maybe I should undertake this project to create a book on Historic German Timber Joinery.

A few more details...

I have talked about two features already that are different in German framing, that is smaller timbers placed closer together. This is a trait common in all German framing, and is one of its distinguishing features. But I haven't given any indication as to HOW small and HOW CLOSE together.

The posts are very small compared to the frames in America. Where we might use something in the range of 8x8 and up, the Germans dominantly use posts with dimensions approximately 5x5", 4x6", etc. with an upper range of around 6x8", and corner posts sometimes as big as 8x8" (on my project the corner posts are 6x9")

Obviously if they were to use such small posts in a bent construction method like we do, their walls would fall apart, or there would be an excessive number of bents. Instead each wall is assembled as a frame -usually piece by piece instead of being assembled on the ground and raised in place- with posts spaced somewhere in the neighborhood of 3 to 5 feet apart, depending largely on desired appearance.

In addition to this, rails (germ. Riegel) are placed horizontally between all of the posts, with at least 1 in each cavity, and often 2 or even more (again, appearance seems to be the biggest factor) These 'Riegeln' are somewhere in the neighborhood of 4x5 inches or so. They stiffen up the frame, and provide more locations for the long braces to attach. The result is an amazingly rigid frame, that has variously withstood direct bomb hits and earthquakes.

The dimensions of the other timbers are all based around these, the sills, plates, purlins, etc. will generally be of similar size to the posts.

In addition, there are 3 different kinds of braces used, each with a different name in German. The first is the simple corner brace, set at a 45 degree angle between a vertical and horizontal timber. If it meets these two requirements, it is called a "band" one such brace at the bottom of a cavity is known as a 'Fussband' and one at the top is known as a 'Kopfband'

If, however, a brace is at an angle shallower than 45 degrees then it goes by a different name, 'Strebe' If it passes from a post to a plate, it is called a Kopfstrebe. If it passes from post to sill, it is calles a Fussstrebe. If it slants from sill to plate, not attaching to any post, it is called a Wandstrebe

The third type of brace is a triangular piece of wood stuck in a corner. This is known as a Knagge, with Fuß or Kopf added depending on whether it is angled up or angled down.

Here is a picture that shows very well a Typical Bernese Swiss house, and shows the framing components effectively

In this picture you can clearly see:
Small posts, spaced close
Rähmbau style, with ends of the joists exposed on the long side
Simple and effective bracing -the x-shaped bracing is known in German as Adreaskreuz, or Saint Andrew's Cross
High windows, a specifically Bernese Swiss feature
Single 'Riegel' per cavity, another typical Swiss feature (simple and effective, and at the same time visually appealing)

Also note the difference in spacing between the posts and the joists, lining up only occasionally.

I am working on making some diagrams of this style of framing to explain things further. In the mean time, ask about any other features you are unclear about. It helps me to better describe things when I know what most needs described.

DLB

It is of interest to consider the relationship of the German style to, for example, the Anglo-American or even the English styles.

In Essence, the older German style of the earlier Middle Ages, Ständerbauweise, is virtually identical to these two styles, with a few variations as is to be expected. In fact, American timber framing is in German referred to as Ständerbau.
The general method of framing is pretty much the same idea. Walls are framed as one mass, in some examples being rather bent-like in configuration. Tie beams are used, in the north taking on a drop-tie form and in the south a form similar to the English tie. floor separations are established by means of horizontal timbers mortised directly into the posts, at times with long tenons extending through the post to the exterior where they are wedged.

But in the 15th century the Germans totally reinvented their frame.

The question must be asked, why did they make this change from the style that was prevalent across most of Europe? What advantages did they see in this? Why did their culture decide that this method was superior, while everyone else continued on with their various versions of the older system?

It must be noted that the Ständerbau style is not a style that was so much passed around among everyone in the middle ages, rather everyone developed this style from its immediate predecessor, the earth-posted frame, which is something that was inherited by all of the people who came under Germanic tribal dominance, hence the remarkable similarity between early medieval German, French, English, Low Country, and Scandinavian framing.

It should also be noted that everywhere where jettied buildings were built, they seem to have developed a style similar to the German Rähmbau, but the older high posted style continued in use in other bu8ildings and in the countryside, whereas in the Holy Roman Empire it passed out of use entirely by the late 15th century in everything but barns.

To understand the difference between German framing and American framing we need to understand the most fundamental variation. In an American frame, the single most important joint is the tying joint. The entire frame is wholly reliant on the proper execution of this joint to function. (There are notable exceptions where trussing action is relied on to accomplish this goal so that the ceiling space is open) In German framing, this joint does not exist at all, except in a few barns built according to the older style. There is no such thing as a tying joint in this tradition; it has been totally discarded.
But we still must resist outward thrust.

German frames use 2 techniques simultaneously to deal with this issue. First, there is a joint system in every frame that resists thrust, and does so quite well. But it is not a tying joint. Instead they use the floor or ceiling joists which always run across the structure to do this. These joists are sandwiched between two horizontal timbers, with simple cogged or dovetailed joints extending about an inch into both of them. These joints are known as kammverbindungen, or comb joints. The timber below the joists is the top plate, and the one below is a special sill that supports the roof framing known as a Stuhlschwelle (literally chair sill, although the roof framework is known as Dachstuhl, or roof chair) This sill generally supports leaning posts that hold up purlins, which in turn support collar beams which tie rafter pairs together and give them support.

The other system used to resist thrust is the Dachstuhl, or roof support, itself. This system effectively transfers most of the roof load into a downward force, bringing outward thrust to a minimum. German roof framing relies exclusively on purlins for roof support, and not on complex trussing. Although at times the purlin support framework can take on the form of a complex, truss-like system. The two types used on houses are the Stehender Dachstuhl, which relies on directly posted purlins, and the liegender Dachstuhl, which relies on leaning posts with special bracing to support the purlins. It should be noted that these posts lean toward the center of the structure, however, and not outward like the leaning posts in many American barns. They rely on struts to convert loads from horizontal to vertical. They also have proven their effectiveness over some very large open spans.

As far as rafters and joists go, spacing varies from region to region. It would appear that in the north it is common for rafter and joist spacing to match post spacing (and post spacing in these regions is perhaps closer than in others), with rafters joining directly into the joists, while in southern regions it is far more common for the rafters and joists to be much smaller and much closer together, with the rafters passing over a special sill to form wide overhangs. Post spacing in the southern rural areas seems to be the widest, at times perhaps exceeding 4 feet. The large Bernese Swiss Bauernhaus seems to employ the widest post spacing out of any of the styles I have seen, averaging around 4 feet or a little less, while joist and rafter spacing seems to be the closest (around 2 feet to perhaps 32 inches) These same Bauernhäuser also tend to be the largest fachwerk buildings.

Here are some books, as promised earlier.

Das Holzbau-Buch by Adolf Opderbecke.
Google books: http://books.google.com/books?id=FAI0i7h...p;q&f=false

Das Zimmermannsbuch by Theodor Krauth and Franz Sales Meyer, 1895

Both are in German. Look them up on Amazon.de and you will be shown many other related books

Here are some drawing that I made up to hopefully clarify things a bit.

Please feel free to bring up anything that is unclear to you

right click->view image to see a larger picture

The first picture is a general picture of the frame, with the various parts labeled with their German names. It should be noted that terminology is note 100% compatible with the common English terms, especially when classifying joints.

You can see very clearly here that each story is framed independently. Pay special attention to the timbers labeled Deckenbalken. These timbers function primarily as floor joists, but the joinery is also designed so that they resist thrust in lieu of tie beams. They are sandwiched between stories, or between the top plate and the roof.

The next picture here shows in detail the joint type known as Verkämmung, or Kammverbindungen. This is the joint used to secure the Deckenbalken. This is one of many variations of this joint, perhaps the best suited for general application.

The Deckenbalken is often extended out past the lower story and the second story wall is jettied out, with the plate out on the end of the joist-beams.

the last picture here shows a breakdown of a simple wall layout. as you can see short tenons are used frequently.

These drawing are made reflecting the following proportions:
4x6 wall posts, braces, cross bars, sills, joists, and plates
6x9 corner posts
4 foot post spacing
8 foot ceilings

Another important matter to consider is how the roof is built. It is important that a roof structure be well adapted to the frame that is supporting it.

In the German tradition, roofs are generally classified into 3 Categories: Sparrendach, Kehlbalkendach, and Pfettendach

A Sparrendach is a roof structure that relies on the rafetrs (Sparren) to bear the load of the roof. This may refer to clear span rafters with no trussing action going on, or it may involve minimal trussing. The general rule the germans use is that a Sparrendach is unsuitable for any slope shallower than 30 degrees.

A Kehlbalkendach is a roof system that adds collar beams to the rafters. For larger spans, purlins can be placed under the collar beam to provide additional support.

A Pfettendach is a roof that uses purlins (pfetten) to directly support the rafters.

Trusses are rare, and are generally more in the category of light trusses when they do appear. Common purlins are all but unheard of. A truss roof is referred to as a Dachstuhl, but Dachstuhl can also be used to refer to a system of purlin support framing.

the 4 most important roof types to know of are the Einfacher Kehlbalkendach [simple collar beam roof] Stehender Kehlbalkendachstuhl [collar beams supporting by direct-posted purlins] Liegender Kehlbalkendachstuhl [collar beams are supported by purlins which are supported by inward-canted posts, a cruck-like construction very common in Switzerland] and Stehender Pfettendachstuhl [directly posted purlins that support the rafters, no collar ties]
pictured in order from the last paragraph: