Bauernhause Roof

First off, here is a picture

1, of a burned out old Bauernhaus

A Bauernhaus is a farmhouse, here it is specifically the main building on a Bernese farm, alongside the Stöckli and the Spycher. The Bernese Bauernhaus consists of living quarters at one end, a livestock barn on the other, and the Heustock, or hay floor, up above under the roof.

For this first post I will just ask a question, what can you determine about the roof framing from this picture? Remember the gable end is not the same.

I have my own conclusions, but I decided to start with a question to see what you can come up with, and maybe you all might notice something I missed.


another picture of the same type of roof.

Here is a drawing I have made of this roof system, and how I think it works.



and a link to a full size view:
[url= http://i538.photobucket.com/albums/ff345/HiddenOrder/Timber%20Framing/scan0001.jpg] http://i538.photobucket.com/albums/ff345/HiddenOrder/Timber%20Framing/scan0001.jpg[/url]

The structure is a series of frameworks that support purlins, which then support common rafters.

Some things I don't quite know what to call them. For example, the structure that supports the purlins. Would this qualify as a truss? Or would you just have to classify it as a framework?
Are the timbers that directly support the purlins posts? Or should they be called truss rafters, or upper cords, or what?
They are similar to canted purlin posts, except they are canted in the opposite direction, like the roof.

A few things should be noted.
1: this assembly lacks what could be called a true tie beam. The timbers that tie, called deckenbalken, occupy a middle ground somewhere between tie beams and joists. They are smaller than tie beams would need to be and larger than joists, and spaced closer than ties but further than joists. They simultaneously fulfill both functions.
However, it seems that the purlin supporting frame is joined into these timbers and not into the top plate (the rafter pairs however are joined to a cantilevered purlin plate.

2: The pulins can also be canted to run perpendicular to the rafters (I don't know if that's the right way to say it)
Example:



Joinery exists in many different forms. Struts for example can be either lap dovetail or mortise and tenon.

Hi DLB,

This is getting on towards being of a similar configuration as a base cruck only employing straight timbers.

I also recall many years ago that John MacFarlane sent me details of a Liegender Stuhl Truss (leaning stool truss) and I rather suspect that this fits into that category.

Regards

Ken Hume

A google search for liegender Stuhl Truss resulted in this:



thanks, Ken.

Says it's not far from the Swiss border. This style of roof is used almost exclusively on the traditional snub-hip roofed buildings of Canton Bern

Berghaldenstrasse 76, Scheune mit liegendem Dachstuhl von 1715. (Bild Stadtarchäologie)
barn with reclining truss (liegendem dachstuhl) of 1715.

http://www.nihk.de/index.php?id=2233
"Multilingual glossary of prehistoric and historic timber buildings" A German web page about historic timber construction