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Unique TF Barn ???

Started by Rooster, March 19, 2011, 12:44:56 PM

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venice

Rooster´s barn.



And this is how the construction looks in its native environment and actually makes perfect sense. :)





We have 2 barns at the place where i grew up in Germany, showing the same roof detail. One building entirely made out of mud/ adobe, the other one made out of sand stone/ field stone.

I vote for craftsman out of my neighborhood near the town of Bernburg at the river Saale. Small world.  :)

venice


venice

@Rooster
Quote from: Rooster on March 19, 2011, 12:44:56 PM
Howdy,
To me, the most unique part of this frame is that the tails of the rafters are joined to either a full tie beam that rests on top of the sidewall top-plate, or for lack of a better description, "stub-tie-beams", which then seem to be attached to a beam that spans the bay and connects the full tie-beams about 24" from their ends. It seems like the framer is using this secondary beam to help control the roof from pushing the sidewalls out at the top. Do you also see this?...or is there a different purpose or idea behind this additional framing system?
So I offer this starter question...Does this design have it's origins in any known ethnic inventory?

Let me know what you all think.

Rooster 

End quote

First off, i am far away from being a final instance on anything.  :D

But looking at our own barn, the roof is designed to work with massive walls made of stone or adobe. In Rooster`s case, the carpenter used a design he knew and adjusted for the framed walls only by pegging the short members where the rafters are resting on, into the tie beam and "beefed up" here and there to keep the walls from bending under load.

In our barns they are not even pegged and the tenons are free floating. The sub-tie shown in my poor drawing as an 12x12 (centimeter) is meant to carry most of the load into the 60 cm thick walls.

It is actually a clever way to design an open unobstructed loft, that allows to stack your hay or straw all the way up till you hit the roof. The use of timber is limited to the bare minimum and the dimensions are quite small for a large roof(in our case).

All in all it appears to me that the guys knew their business and addressed the structural challenge, using a roof designed for a stone building on a framed one, accordingly.

venice

D L Bahler

After more study, this is my observations on this style of framing.

First of all, very good information Venice, thanks for sharing.

I believe this to be an example of the German style of rafter roof framing, or standing roof (Sparrendach). In this type of framing, rather than setting rafters into the plate they are set into the crossbeams or anchor beams.
On a house, it's a simple matter to have one anchor beam for each rafter pair which also serve as ceiling joists. But like venice pointed out you don't want this in a barn, where you want to be able to stack hay up to the roof. So carpenters devised this method of tying the cut off anchor beams (here called Strichbalken) into a support beam.

venice

You are right on with the "Sparrendach".

Mr. Bahler knows it, but for those who might be interested too; the idea behind the "Sparrendach" design is to create a triangle, jointing the rafters into the ceiling joists with mortise and tennon or half-lap joints in some cases. The joist is acting as a "draw band". Therefore, most of the load that is transfered into the walls(except for windload) is vertical.

The roof construction, using the "Sattelbalken" - as the short member that is resting on the wall is called around here, has been in use at least since the 12th. century.  :o
It can be found on churches as well, making room for the vaulted ceiling.

It is amazing how much knowlegde the master carpenters and architects had back then. With no Google around, probably gained by trail and error.  :D  And it is also amazing how long carpenters would use the same technique.

venice

D L Bahler

Venice you seem a very knowledgeable person, I should very much like to confer with you to get more information about the old German techniques. My training is Swiss, and most of my research is Swiss, but I'd like to know more about German.

I was somewhat unsure of whether the term 'Sparrendach' is used to the north, and I was certain you would have a name for the stub ties other than 'Strichbalken' since that is an obviously Swiss (to me) term.


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