Half-Timbered Farmhouse Construction

[D L Bahler]

It has been some time since I've been able to post on these forums. 
I'd like to share with all of you one of my latest projects. This is a large sketchup model of a fairly  typical Bernese (Swiss) farm house. -Specifically, the architecture is consistent with the central regions of the Canton of Bern, particularly in the west of the Canton between the cities of Bern and Thun. It lacks the larger overhangs one would find in the Emmental, and has the more subdued roof line more typical of the south (Here it is modeled with a 10/12 pitch, whereas in the north roofs would have a pitch of 45 degrees or greater)

The style is more of a "Modern" building, using the half-timbering (in Switzerland called Riegelbau, and in Germany known as Fachwerk) style that became dominant in the region from the end of the 18th century until the present day, though many regions have preserved older solid wood construction methods even today. 

Half-Timbering in the German-speaking world is likely descended from the building methods of the Swiss subalpine ranges, where the frames were built in a very similar style, only using solid wood infills in lieu of braces and brick or stone between the timbers. This technique dates back perhaps 1000 years, and originated as a modification of the local log building forms, driven by influences from the timber framing techniques to the north along the Swiss Plateau. 

The overall design of the building would place it some time around 1800. This is not modeled after a real building, but an attempt to create a fairly "typical" timber frame to demonstrate the traditions. As such it is basically an older Half-Timbered form typical of the southern range of the great Bernese Bauernhaus (a farmhouse incorporating several buildings under a single roof). What this means is that it incorporates older architectural elements such as the larger hip on the front (Halbwalmdach" or half-hipped roof, as opposed to the "Viertelwalmdach" of "Krüppelwalmdach" or quarter/cripple hip roof more typical later, particularly closer to the city of Bern) and the full hip on the rear, where newer buildings might have no hip at all or have the same degree of hip as the front. It also features a single roof pitch along the length of the building, whereas newer buildings tend to have a shallower lower roof angle due to the framing method used to support the roof. 

This building features a posted roof construction more typical of the southwest, rather than the "Liegender Binder" technique that took over later. Many older buildings today feature a more modern "Liegender Stuhl" type of roof construction atop a much older wall frame that originally supported a flatter roof. This is possible due to the genius of southern Bernese timber framing, in which the wall ad roof structures are almost entirely independent of each other. 

In keeping with a more archaic character, this building also lacks the so-called "Ründi" on the front gable, a rounded decorative feature typical throughout the Canton. 



 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Half-Timbered construction in this style stands in contrast to more familiar styles of timber framing in a number of ways. The biggest defining characteristic is the use of a larger number of significantly smaller timbers to support the roof, and posts are typically only a single story in height.
There is no concept of "Bent" or "Bay construction in the southern Bernese forms of timber framing, which descend from log building. Instead walls are assembled piecemeal. The typical method used today involves assembling entire lengths of single-story wall sections in the workshop and typing them together with permanent steel rods linking the sill and top plate. Of course some elements must be omitted to allow them to be assembled on site. 
As mentioned above the framing of the roof is independent, for the most part, of the wall structure. By that I mean that the wall posts themselves do not directly carry the roof sills and purlins, rather a roof support system (here a series of posts supporting purlins and the ridge beam) are stacked on top of the walls. This eliminates the need for tall posts. The tallest post in this structure is about 12 feet. 

The support for the roof does not always directly follow in a straight line from purlin to the foundation. That is, the purlin posts may not have a wall post directly underneath them. In this way the room layout is allowed to proceed without being determined by the location of the supporting members, although good design tends to allow for direct support. In the structure above, the roof system conveniently divides the structure into thirds along its width. 

Older Bernese timber frames employ massive timbers -typically much larger than anything we use in American timber framing. This is largely due to the availability of large straight trees, and the practicality of not hewing overly small timbers out of the large trees. Half-timbering arose when technology made it more practical to transport trees to the sawmills, and then back out to the rural farms where these buildings were constructed. The use of smaller timbers with greatly simplified joinery meant that buildings could be constructed much more quickly than before at much lower costs. 

Typical wall posts are roughly 4x4 to 5x5 (Measurements are approximate, since the local inch was not the same as our US Standard inch) with larger posts used in the corners and at wall junctions, with corners removed so that a small bearing face would project into the rooms for attaching paneling. 

The only large timbers are used in the roof structure. Here 8x8 and 8x6 timbers are used, which are fairly typical, and 8x10 is shown for the ridge beam. 

Another notable feature of this building is that it may actually get built... 

[Fallguy]

I am looking forward to following your progress on this project. I 
hope it gets off the drawing board. How did your Bread oven turn out?

[D L Bahler]

I don't have any pictures of it on hand. It's usable, but could still use some cosmetic work. I haven't extended the roof over it to shelter it yet. Hopefully that gets done this summer. 

I just finished recording all of the parts so I can compile cut lists and order sheets.

There is a total of about 1265 parts in this frame, give or take a few

[D L Bahler]

Here is a possible solution for infilling the timbers. 

The requirements are as follows:
Visible timbers on the exterior
Frame obscured on the interior
Non-redundant or wasteful infill method (that is, don't make a whole frame within the frame, or else why timber frame the thing to begin with?) 
Reasonable insulation properties 
Suitable substrate onto which interior wall coverings can be fastened. 

I want to avoid strapping 2x4's onto the frame, as that seems rather wasteful. I don't have tremendously large spans between timbers (about 4 feet in most cases) so the whole situation is much easier to solve than with 16 foot bent bays. 

Below is a quick model i whipped up to show a possible solution. 
Basically it works as follows: 
Shallow grooves are cut into the sides of the timbers to hold wooden planks -here depicted as 3/4" standard pine, but I could also use 4/4 rough sawn wood of any variety. This does not need to be high quality wood. A small strap would be attached to the back (inside) to help maintain vertical position, and chicken wire fastened to the outside to hold plaster/stucco. The wire is the material holding the plaster, and not the wood. The wire would be attached to the center of each plank. In this way instability of the wood planks should not be a major issue. 

The inside is simply boarded over. Probably with tongue-and-groove boards, though they could also be doweled together if cheaper rough-sawn lumber is used.. 

This should provide a sturdy enough connection for any interior wall covering. 

To insulate the assembly, the cavity would be filled with cellulose, providing a total r-value of around 15 (about r-6 at the timbers themselves) 



 

[D L Bahler]

Here is another model I made, demonstrating a more typical southern and western Bernese farmhouse. 
This is reflective of the building styles typical where log and timber building have blended together, due to the slow influx of timber building into the previous range of Alpine log building (this mixing of building styles likely occurred 1000 years ago, or even earlier.) 

This style of building can be classified as either log or timber building, depending largely on the attitude of the carpenter who made it. Sometimes these are built as true log buildings, with the loads born by the horizontal timbers. This is ensured by cutting the upright posts somewhat short of the wall height, so that they do not pick up the structural loads and allow gaps to form at the tops of the walls as settling occurs. Other times they are built as timber frames, with the posts bearing the weight of the structure instead of the squared infill. Both might occur within the same region. The method of inserting vertical timbers into log walls originates largely as a means of allowing the construction of much larger buildings than log building would otherwise allow. 

Over time these structures evolved to resemble timber frames more and more, and eventually were supplanted by "Riegelbau" style frames with log infill -though that is not to say that this older practice has died out entirely. 

The oldest iteration of this style of building can be found on either side of the Stockhorn chain, in the Simmental to the south and the upper Gürbetal to the north, eastward toward the city of Thun. This is essentially an alpine style log building with a timber frame lower story and an interlocking-corner log built upper story. These structures were originally built with the low-angled "Schwardach" of the Bernese Alps, built to hold loose-laid wooden shingles weighed down with heavy logs and large stones, though many had their roofs replaced with the steep hipped-roof style of the Berner Mitteland over the last two centuries. 

From here the style evolved into the "Tätschhuus" seen to the north of the Stockhorn Chain from Amsoldingen to Wattenwil. This is a true timber frame, still featuring the low-angled roof of the Alps. Some time after 1700 the large Bernese farmhouse took over this same region, but the hybrid framing persisted. 
A similar development occurred in the Upper Emmental and the Schwarzenegg region as well. 

This development occurred largely to meet the demand for much larger farmhouses, often built to house two or three families and a large number of dairy animals. The older, smaller structures were built during an era when goat herding dominated the region, and the larger farmhouses arose to meet the demands of dairy cattle. 

What is remarkable is that these ornate structures were often built by very poor farmers. 

This model is somewhat larger than typical, though buildings of this size certainly do exist. It features the sort of architecture one would expect to see in the Thun region and in parts of the Upper Emmental. The architecture and design would place it some time between 1750 and 1850. The 5 post roof construction places it in the western range of the Bernese farmhouse or into the closely related regions of Freiburg. This sort of construction is typical of the western Swiss, and shows a kinship to the grand farmhouses of Romandie (French-speaking Switzerland) 



 

 

 

 

 

 

 

 

 

 

 

 

 

 



What we have here is a front house section built in the "Blockständerbau" or Log-timber frame hybrid style and a rear barn section built in the "riegelbau" style and clad with a sort of Board-and-Batten style siding typical of the region. What this is is simply 2 layers of vertical cladding staggered against each other. For this model I used 6" board 10" OC, with the outer layer being staggered by 5 inches.