Restoring an old house in Slovenia

[jcalderera]

Hello,

I am a new member to the Forestry Forum and was hoping to get some advice from any of you that are kind enough to take the time to help.  I have lived in Slovenia for about 9 years now and I have an old house on my property (200-300 years) that I am hoping to restore.

I don't have any timber framing experience but I have some woodworking experience making furniture,  using mostly hand tools for making joinery.  My last project, making a greenhouse, was as close to timber framing as I.  I practiced knee braces (thanks to a killer tutorial I found here...Thanks Mr. Jim Rogers!) and undersquinted wedged scarf joints.  I may be in over my head with this renovation project but I genuinely believe I can pull it off with the correct preparation.   

First, it may be wise to accustom myself with the correct terminology  for timber framing.  Before I ask specific questions about the joinery, I should know the names of what I am joining.  Below are some pictures of the house and my best guess as to what all the components are called.  If possible, can someone please correct what is sure to be several incorrect names of the components?

 

 



Thanks,

John

[D L Bahler]

What part of Slovenia? Are you perhaps nearer the Austrian border? I ask because the framing seems to be related to German framing methods. I know Slovenia has a long history of rule by Austria, so this would make sense. (I've bought some very old Austrian-made tools from Slovenia and Hungary before) 

Terminology depends a lot on who you are talking to. 
What you have here I would say is a typical Austrian "Stehender Dachstuhl" complete with Austrian/Alpine Germanic style joinery. 

In English I'd  describe your parts like this, using your labels for reference:
"Queen Post" -this is not a queen post, there is no truss. Instead, these are Purlin Posts, seated into a tie beam, though it's not exactly a tie beam either (but you'd still probably call it that in English I suppose) 
The tie beam, really the tying function is served by the joists that you can only sort of see in the lower picture. What you have as a "tie beam" really is mostly a support beam for the purlin posts, and isn't actually the primary means of resisting the outward thrust. 
"Collar tie" I suppose is labeled correctly. But probably "Collar Beam" is more accurate. This is not a tying joint, it works in compression, tying the rafter pairs together against asymmetrical loads. 
Under Purlin -you could just say purlin, or maybe Middle Purlin
Wall Plate -well not exactly. This isn't a wall plate rally because your walls are of stone. Instead this is part of the roof frame. In German I would call this a "Dachfuss" which would translate as roof foot, not sure what you'd call it in English because I don't know that you really see a direct analogue to this in English or American framing -maybe you do, but I'd guess it would be in Penssylvania and built by Germans. 
What you have labeled with ?? I would call a flying purlin (In German I'd called it "flugpfette" which means the same) The purpose here is, the rafters seat into the "Dachfuss" which in turn distrubutes the horizontal loads into the joists, and shorter rafters at a flatter pitch are shot out over this flying purlin in order to create an overhang. Very typical of framing from within or related to southern German traditions. However the framing of the opposite wall seems to be different? 

I was trying to figure out why there were 2 beams at the eaves wall, where you have labeled "wall plates" on the lower picture, because in my experience usually this assembly is a little bit different -the "tie beams" are extended out past the lower "dachfuss" (sorry I just don't quite know what to call it in English, except maybe Roof sill)  and the "flying purlin" is placed out past the walls instead of above as you have here. But you have two beams here because the flying purlins are placed above, and they needed a continuous beam for the sake of joinery. Again a typical German approach -when the joinery becomes too complicated in a single beam, you just slap another one on top to simplify things and preserve the strength of the members. German joinery tends to remove far less material than English/American and French joinery, which lets them get by with smaller timbers -even though they had far less need of it than the English who chopped all their forests down. 

So what I see going on is this: 
If you look at the lower picture of the exterior view, you see on the gable there are 2 beams stacked against each other. The lower beams are the ceiling joists, and hold the wooden floor that you can see in the upper picture. The upper beams are the tie beams, and really the main function here is to double up the beam so it has more strength to bear the purlin posts. The connections here are actually taken from log building -really all southern German framing has borrowed elements extensively from log building, which you see with the passed lap joints at the corners.

Also looking at the lower picture, I suspect there are some parts missing. Is this correct? 

[Chilterns]

What is the white stuff - snow / spray on insulation ?

Are the eaves supposed to be open for ventilation / drying ? and if yes was the building (attic / loft) used for storage / drying of agricultural produce e.g. tobacco ?

The rafters and collars are black suggesting that the building was either a domestic building open to the roof or heated to dry a crop like brewing hops ?

What is present on / in the ground floor / basement ?

Some more pictures would be useful especially posted to a photo website.

Are the walls made from masonary rubble and / or are the upper parts earth based ?

Where a ridge is present the rafter feet will tend to be pushing inwards rather than outwards which goes some way to explain the reverse wall plate assembly i.e. placed on top of the tie beam.

[jcalderera]

Thanks for all that great info D L Bahler!  It was very helpful and informative.  I really appreciate it.  I'm loving learning about timber framing history. 
 
To Chilterns, I will work on answers to your questions in my next post.
 
To answer your questions, DL Bahler: 
 
What part of Slovenia? Are you perhaps nearer the Austrian border?
The town I live in is called Peče.  It's very close to the geographical center of Slovenia, about an hour from the Austrian border.  It's such a small country, even the furthest part of Slovenia is relatively close to Austria!  Surely Austria had a big influence on the old buildings here. Not many of the old structures are left standing, though.  Most people choose to tear them down and build something new.   
 
What you have labeled with ?? I would call a flying purlin (In German I'd called it "flugpfette" which means the same) The purpose here is, the rafters seat into the "Dachfuss" which in turn distrubutes the horizontal loads into the joists, and shorter rafters at a flatter pitch are shot out over this flying purlin in order to create an overhang. Very typical of framing from within or related to southern German traditions. However the framing of the opposite wall seems to be different?
 
The opposite wall does not have a flying purlin, only Dachfuss.  The roof has a 45 degree pitch, so the ridge is not centered on the house.  See below picture:


  

 

Also looking at the lower picture, I suspect there are some parts missing. Is this correct?
 
Yes, you are correct.  There was an additional tie beam at the end of the house that seems to have been cut away.  You can see it in the above picture.  You can also see how the flying purlin is falling out of position. 
 
Now that you have provided me with proper names, I can more accurately ask some joinery questions I have:


 Dachfuss:  As it stands, the Dachfuss's  are one continuous length (about 14 meters or 46 feet).  I cannot get a 14 meter piece of timber so I will have to join 2 pieces.  What kind of scarf joint do you recommend?  What about placement, assuming I can acquire a 9 meter timber? 
 
Knee brace:  Below is a picture of the current knee brace joinery.  Several structures I have seen around here (mainly barns) have this type of knee brace.  I don't love this joinery because only the pin keeps it from falling apart (A couple in this house actually have fallen apart).  I guess an advantage of this joinery is that it is easier on raising day?  Are there other advantages?  I'd prefer to do a knee brace where the tenon is fully housed.  What are the ethics on changing joinery in a house restoration?  After all, this house has been standing for over 200 years, who am I to question or change the joinery? 


 
 
 
 

 
Purlin post:  See the below pic for the current joinery.  Because the timbers are rectangular (20 cm x 16 cm, or 7.9 inch x 6.3 inch), the Purlin post overhangs the tie beam.  This doesn't seem right to me but......again with who am I to question a structure at least 4 times older than I am?  Any thoughts or suggestions?


 
Rafter-to-flying purlin connection:  The rafters have birds mouths, but the flying purlin also has a channel cut out of it to receive the rafter.  See below.  Is this common?  Is this worth replicating?  Same ethics situation. 


 
Flying Purlin –to-Purlin post structure:  See below picture.  I should have asked for the terminology for these pieces in my last email.  The horizontal piece connected to the flying purlin is a lap joint with a pin.  Most of these in the house have failed.  Is there a better option here?  I'd also like to do an oblique lap joint (correct term??  Kind of a half dovetail?) where the  horizontal piece joins the timber that is at a 45 degree angle.  Ethics or not, it seems obvious to me that the current formation is sub-par. 


 
Collar beam:  As it is, the rafter is joined to the collar beam and only the collar beam is seated on the purlin.  See below.  A lap joint is used here.  Is this common?  I don't like that the rafter is not at all seated on the purlin and I don't like that, because of the lap joint, essentially only half the rafter is seated horizontally on the collar beam.  Any thoughts?



Thanks!

John

[jcalderera]

Thanks for the interest, Chilterns!  I'll do my best to answer your questions:
 
What is the white stuff - snow / spray on insulation ?
 The white stuff that is crumbling away is Stucco, I suppose.  It is the façade. 
 
Are the eaves supposed to be open for ventilation / drying ? and if yes was the building (attic / loft) used for storage / drying of agricultural produce e.g. tobacco ?
 There are no signs that the eaves was ever closed.  No nail holes to suggest it was covered with boards.  We live in a small farming village.  The attic was in all likelyhood used for storage and drying.
 
The rafters and collars are black suggesting that the building was either a domestic building open to the roof or heated to dry a crop like brewing hops?
Perhaps some of the blackness is due to the black kitchen below.   This is a room where they made a fire for cooking and heating.  There is a chimney now, but in the past it was just a small window for ventilation.  These rooms quickly get covered with soot, hence the name, black kitchen.  Its not air tight, so im guessing plenty of smoke got into the attic.  In my first post you can see the domed roof of the black kitchen on the left side of the interior view picture.   

What is present on / in the ground floor / basement ?
The house is much smaller than it looks, if you ask me.  The ground floor consists of a foyer, a living area with a radiant fireplace, a black kitchen and one other room.  The radiant fireplace (as I call it) isvery common in Slovenia.  Thick ceramic tiles that stay warm long after the fire goes out.  They are great! It is the source of heating in the house I live in now.   In this old house, the opening for making a fire is in the black kitchen. The "other room"  was a kitchen when last inhabited, but almost certainly served some other purpose in the distant past.  There are 2 basements, one on each end of the house.  There is no drainage around the house and they have no floor, so the basements are extremely damp and flood with heavy rain or snowmelt.    Now the house serves as my workshop and storage area.   

Are the walls made from masonary rubble and / or are the upper parts earth based ?
The walls are stone, about 70 cm (27.5 inch) thick.
 
Hope this helps!
John

[Chilterns]

Hi John,

Now this is beginning to make sense.

Please look at your picture (Flying_purlin_connection.jpg) where some little openings can be seen in between the upper and lower plate. This is a pigeon loft where the building occupants could gather eggs and pigeon squabs (baby pigeons) which were the original fast food.

The oven is most probably a later insertion following a move away from the open black kitchen. This building did not operate in open mode for very long as the black is fairly limited and presumeably would be confined to one bay with the other for the pigeons. Look for signs of hooks and / or pegs where meats (pork) could have been hung to smoke and preserve.

I don't think that redesigning the joints is appropriate in such an old house - much better to just give the current design a bit of help where this is needed. The braces shown in pic (Knee_brace_joinery.jpg) show no signs of separation with this type of joint being used quite a lot in eastern Europe.

I don't think that it is appropraite to try and redesign / rebuild this frame using American / Swiss or western European traditional practice. You have a little gem - guard it carefully.

[jcalderera]

Copy, thanks!  I will heed your advice to replicate the original structure as closely as possible.  I agree that it is a gem and will do my best to keep tradition alive.  I even hand hewed a few of the beams I will use to try to get a feel for how things were done in the past.  Although most beams in the house don't appear to my untrained eye to be hand hewn, the east wall definitely is.

Great info about the pigeon holes!  Thats really cool!  I have a museum right in my yard and I am loving learning about it. 

One part of the house that I can't replicate is the continuous 14 meter doubled up Dachfuss.   The longest timber I can acquire is 8 meters, 9 meters at best.  Do you have any suggestions for the type of joint I should use and the locations?  Below is a picture of the front of the house (pigeon holes and platform seen on the left side of the house).



 

On that subject, I would love to keep these beautiful timbers intact!  They seem to be suffering from dry rot, but I am no expert.  They are in better shape than the rafters, and collar beams but they are not perfect.  Some people who I consider more knowledgable than me looked at the beams but did not give me a definite answer.  I guess it's hard to make this determination without getting a real eye on it, but if someone can give me a more definitive testing method for the integrity of a timber, I'd be thrilled.

If you are interested in seeing more pictures of the house or wanting more info, I'm happy to oblige.    I am new to this forum and new to forums in general, so I don't know the general do's and dont's of posting.  I don't want to clog up the site if it is unnecessary.   I really don't even know if "clogging up" a site is a thing.  Maybe email is a better method if you have interest?

Thanks again!

John

[D L Bahler]

This building, again, shows obvious Austrian design. As does most of the timber framing in the former Hapsburg Empire, and other parts of Eastern Europe were German settlement was formerly quite widespread (before the soviets evicted them following WWII)

If this were in Austria, I would actually say the building is 2 to 300 years older than you said, based purely on the joinery. But as this is Slovenia I don't know enough to make any sort of educated guess on that.

The reason for this sort of joinery is that German-type frames are not assembled as bents like American frames are, they are rather put together piecemeal. The braces are the last things to be put in place, and this sort of joinery allows you to do that.
Honestly, the performance and failure rate of let in vs. mortise and tenon bracing is not all the different. If you had mortise and tenon joints instead of lap dovetails, probably nearly the same amount would have come out. Actually since your building is asymmetrical, braces that work only in compression would be at a distinct disadvantage. Personally I actually prefer this sort of brace joinery in most applications. The reason I think many later traditions used mortise and tenon bracing is because it's easier when you assembling things in bents. The joint is simpler and faster to cut.

Nothing about redesigning according to Swiss methods. The methods used are basically the same aside from a few minor details. I mention Swiss and Austrian only to draw parallels and explain the theory behind the original design.

I would actually suspect the building was widened at one point. The roof frame probably was originally symmetrical, because there's no reason for it to have been designed this way from the beginning. The one wall was knocked out and the building expanded slightly. These seems to be supported by the exterior appearance, where the stonework in the gable does not match, and it looks like there are some left over pieces of the original assembly still in the wall. It's also possible a much older roof was recycled and modified and set atop a new set of walls at some point.

In Slovenia, did you historically have separate buildings for every function of a farm? This would be the case in parts of Austria, and also in Graubünden and Ticino in Switzerland and across the Alps into northern Italy. The kitchen was one small building, the sleeping area was another, etc. Perhaps this was done in your region also, this being partly why the building is so small. It is also possible the second room was used originally for drying and smoking meets, which I would say is the case if this was in Ticino.

What you say that only the pins keep these braces from falling apart -this is also true of mortise and tenon bracing. In Indiana where I live, most old barns the braces have pulled out because they cannot function at all under tension, and when heavy wind loads or foundation problems cause the barn to shift, many of the braces will pull free. These dovetail braces have in some cases in Central Europe lasted 800 years, so I think the technology is good enough. No matter what sort of bracing you use, if the foundation is compromised they will fail.

As to the posts being wider than the beams, they probably just cut the timbers to the dimensions convenient based on the size of the log they were hewn from. So the extra width is just out of convenience, and doesn't matter. The load paths are fine.

SO you have long struts from the tie beam to the purlin posts, and the short horizontal struts serve to hold the upper purlin against the inward pressure from the rafters.

There is no structural ridge beam. The rafters thrust outward. However, the lower pitched rafters lean against the flying purlin and push them slightly inward, but only if they're not securely fastened. Again, there are no wall plates here. All of the timbers are roof timbers purely. This is a very typical German type connection. Where the wall is framed, the lower beam might also be the top plate of the wall, but the upper beam is always a purlin. The two beams clamp the tie beams/floor joists together, support the rafters, and greatly simplify the joinery by minimizing the amount of wood taken out at critical points.
What concerns me is how the rafter feet are secured on what I would think is the modified side. It appears to me they land on extended joist/tie beams and maybe are connected with a mortise and tenon. This is fairly common on old Churches and also some medieval German buildings, but it's a bad connection that has a high rate of failure, and in cases of churches tended to require reinforcing later on by metal clamping and strapping.

A more typical connection in German type construction for the lower-pitched rafters would be just to pass them over the purlin without the crow's foot. In your case, where they have withdrawn it might be appropriate simply to drive a timber screw in to pull the connection back together.

Do you know any German? I can send you some literature if you can on late medieval German roof framing that would help you understand this better.

[Chilterns]

I have shared your pics with Heather and she advises accordingly :-

What a fascinating building! This is a version of the Scandinavian tradition of timber building where you construct a rectangular box one storey high, then use the top as a platform to build another box, etc. and construct the roof when you get as high as you want. So there are double wall beams, often with the joist ends trapped between them and visible externally, and double wall plates, too.

In this example, the lower storeys may have always been stone, or underbuilt later, but the principle is the same – box on box, very little carpentry except halving joints, gravity does the work. The roof is built in the same way, a tie beam across the top of the box below, queen posts on that, purlins on the queen posts with elbow braces, collars laid across the purlins, etc. The corner joint looks like a version of the Scandinavian slot mortice with a long tenon extending right through and beyond the mortise, then an external wedge peg through the tenon.

The loft is for drying something – highly ventilated at eaves level, though whether that is original would need close examination. It could be that the pitch of the rafters has been changed by insertion of that 'flying wall plate' supported on (raking?) stub posts sitting on the lower wall plate, and rafters lifted at eaves end only. Or that is the original construction, since the gable ends also appear to be originally ventilated with open studding.

Since it has an oven and is called a black kitchen, presumably it has been some kind of bakehouse, or at least had an open hearth. The loft floor looks like plaster over timber baulks, which could once have had ventilation gaps between them, hence the smoke blackening. The closed oven and the plaster floor probably later? Plaster for fire risk reduction? Dispersing the heat to whatever is being dried? Or smoked, though there would be more sooting in a smoke house. There does not appear to be a chimney. What was the local fuel for the black kitchen? What is / was the local high-value economic crop? Nuts? Grain? This is for a clean food crop of some kind, and was probably only used seasonally.

Definitely not pigeons!

In respect of conservation? Do they want to close the ventilated loft for dwelling space? Is the oven on the ground/basement level, or the floor level at the top of the steps? Was the whole volume of the building heated originally? Or animals below? I think that the owners need to understand what the building was constructed FOR and how it was USED, probably seasonally, so climate would have influenced design; it was almost certainly not a dwelling house.

Hope this is enough for now, and that you find some answers.
 
Heather

So the approach that needs to be taken before you do anything is to undertake local vernacular building research so that you develop a better understanding before any original material is lost.

You have now advanced to the point of now knowing what you don't know and so the next step is to advance to knowing what you didn't know.

Chilterns

[D L Bahler]

With respect, 
This has little to do with anything Scandinavian, other than perhaps that the referenced Scandinavian methods are themselves an adaptation of German Fachwerk. Danish carpentry, for example, is almost entirely based upon German methods. The Germans Zimmermänner traveled far and wide. The influence of the Holy Roman Empire in the late Middle Ages was tremendous, and this compounded by the rise of the Prussians, Habsburgs, and the Hanseatic League more or less headed up by Hamburg resulted in the dispersal of German techniques through northern and eastern Europe. In Europe, the German carpentry traditions are by far the most important and influential for these reasons.

The techniques themselves originated in Central Europe, often thought to have appeared first of the Swiss Plateau somewhere in northern Switzerland and southern Germany/Bavaria. They are themselves the result of fusing the older Germanic style of timber framing (very akin to what you will find in France and the low countries) with log-building traditions indigenous to the Alps. Their pedigree is mostly Celtic with some influence from Roman holdovers and the influence of the Germanic peoples. The scandinavian influence in this region would be very very ancient (4th-6th centuries) and even then is generally very slight. 

The platform framing in question evolved from Alpine log building, beginning by replacing the corner joints with upright posts and this in turn fusing with framing methods just to the north. This is why many historians consider Fachwerk is likely to have first appeared somewhere around Bern or Basel in about the 13th century. In fact, there are proto-fachwerk buildings in and around the city of Bern that are about this old, maybe a century younger. 

The building, again, is definitely of Austrian design -which as the OP confirms is not at all suspect and incredibly likely. Remember that Slovenia was under the rule of the Hapsburg Empire for centuries, and had significant ethnic German settlements. You see, for example, in Poland -particularly in the cities- a great deal of German carpentry, and even the rural carpentry displays a strong German influence. Even in Russia there is a great deal of German influence, because at one point the Czars were fascinated with the Germans and imported as much as they could from them -including inviting large settlements of ethnic Germans into their Empire. This is why, for example, Tschaikowsky writes his music in the German system, and labels it all in German. 

The building of stone walls underpinning such a roof is entirely typical, especially if it was built for cooking. What I see here has nothing that is particularly remarkable or unusual within the context of the southern German carpentry tradition -note also, German carpenters tended to travel extensively, and it was part of their training to travel to foreign lands, especially those within the rule of their sovereign like Slovenia would have been for the Austrians, and build. This is why German carpentry is so widespread and tended to push out many of the indigenous Slavic traditions in many regions. 

There is really no mystery to this at all, other than why it's asymmetrical I suppose. There is, perhaps, a difficulty in that you are expecting to judge it by the Anglo-American framing traditions. This is a mistake, because the operating theories that drove German design have virtually nothing in common with English practice. When looking at a German type roof, you're best off to throw you're knowledge of American and English carpentry out the window. See my post from a couple months ago on the subject, where I detail some German style roofs.

As to the "black kitchen" this is a very very old central European custom that is almost universal throughout the Alpine and sub-alpine regions of Europe. (Schwarzküche in German) Like he said, usually you just had a hole in the wall to let the smoke out. You can even find some of these in old houses still like this is Switzerland. It's really not pleasant to be in the kitchen at all, and I feel for the poor women who had to live like that all the time in centuries past. It's not likely the ceiling boards were vented. If there was anything stored above it would probably have been hay, and you can guess why you would not want the floor boards vented to an open fire underneath. So in my region in Switzerland, we actually had a modification of the black kitchen that is known as the "Burgunderkamin" or Burgundian Chimney. What it basically is, is a giant wooden hood over the hearth that narrows to a small wooden chimney that goes out through the roof. The whole thing has a shingled wooden flap on top that you can open and close with a very long wooden pole. It's one of the oldest chimney technologies in the world, actually (chimneys have not actually been around for very long at all). But just a few kilometres away, in fact anything east of the Aare river, you have the "Black Kitchen" instead. This "burgunderkamin" you'll still find in the Berner Oberland. The sheer amount of smoke produced by this is enough to blacken the wood in the loft even without intentional ventilation. The fire burns very inefficiently because the oxygen levels in the air are low and the heat of the fire is generally quite low. (I've operated fires just like this on the Alp.) In fact, the fact that the timbers in the loft are not completely black is consistent with there having been no intentional ventilation, hay storage, and a long period of use. I say this from experience -it's entirely consistent with Swiss buildings of this sort that are about as old. Swiss traditions are not really any different in most respects to the broader Central European customs. We're all united by a common Alpine culture that predates the Romans by thousands of years.

The reason for the double "plate" is very very simple. The lower beam exists to give the carpenter something to reference for the purpose of laying out joinery and positively locating the tie beams/floor joists. It's not likely there was ever a wood frame underneath it, nor is it in any way a holdover from framed design. It's an important part of how these roofs are designed and laid out, and without it the joinery would have been extremely difficult to figure out and execute with any kind of accuracy at all. Plus it distributes the loads more evenly into the stonework, which if you notice does not have any kind of ledger. This is a rubble wall, which is what you'll see anywhere in Central Europe even on pre-gothic churches and castles. Only the corners and door/window frames have any sort of cut stone. Putting a wooden ledger makes things just generally easier. Same reason you put a sill beam under you walls instead of keying the posts into the masonry. You'll see exactly this sort of assembly on just about every church built before 1800 anywhere from central Europe to Denmark. 

I did mistakenly think there was an "aufschiebiling" on one side from the original pictures, which is where you just stub rafters out past the walls at a flatter angle than the primary rafters. But with you last round of pictures I can see this is not the case. I misinterpreted what I was looking at the first time. 

[Chilterns]

Thank you D H Bahler for that diatribe.

I am gaining the impression from you that all roads lead to Switzerland - however with such clever inventions attributed to the Swiss as the cuckoo clock that should really come as no great surprise.

Other people's impressions are as equally valuable as your own as this helps to stimulate the owners enquiring nature to encourage him to investigate, research and arrive at LOCALLY based solutions.

[jcalderera]

Thanks for all the input guys.  I appreciate all the time and effort you are going through to explain things to me.  I am learning tons!

For a while, I have been on the fence about whether or not to go ahead with this renovation.  To do it correctly will be very expensive and the final dwelling will not be very practical.  All this conversation, learning and enthusiasm from y'all are making me lean towards going for it.  

I agree this house has Austrian roots.  While Slovenia has developed its own styles, traditions and methods, they certainly stem from our neighbors.  The majority of tools used in Slovenia go by their German names.  To me, that says a lot.  One of the first words I learned while living in Slovenia was Wasservaga. 

Chilterns, don't discount your pigeon hole theory!  This most likely what it was.  I have been told by representatives of cultural heritage in Slovenia that they are, in fact, pigeon holes.  I have also seen examples of this in Slovenian architecture books.  

D L Bahler, I don't speak German (other than the names of several tools!), but if the literature you mentioned has good pictures and diagrams to follow, I'd be happy to have it.

Being so knowledgable on Central European carpentry, can you tell me a typical scarf joint used for the Dachfuss on such a structure?  And the best locations?  

Thanks!

John



 

[D L Bahler]

http://archiv.ub.uni-heidelberg.de/volltextserver/13089/1/Historische_Dachwerke.pdf

This is an examination of historical roof structures from the cities of Konstanz, Ravensberg, Rottweil, and Villingen. So this is all South Germany in Baden-Württemberg and would be fairly consistent with other Central European methods (Baden-Württemberg, Bavaria, Switzerland, Austria, and the German diaspora in the former Austro-Hungarian Empire would all have close cultural ties and a lot of commonality in carpentry practices) Page  49 will have a picture that is somewhat like what you have in some ways, only this example has a ridge beam and your building does not. There's nothing quite like your structure here -partially because of regional difference, partially because these examples are much older, and partially because it's an entirely different class of structure, executed at a very different scale. The examples in this document are all medieval, all fairly large, and are generally public buildings like churches, government halls, taverns, and houses for the upper classes. Different sort of architecture than what you find in barns and more rural houses, but you see the same basic design principles -just that in these examples they are executed at a higher level. 

-Cukoo clock is Bavarian, not Swiss. Bavaria and Switzerland don't even share a border, unless you count the fact that they both touch Lake Konstanz  (actually it might be a Schwarzwald thing, I'm not really sure. Cukoo clocks in Switzerland are all bought off the Germans and sold to gullible tourists who expect to find them)

Argue if you want, But what I'm sharing is really nothing controversial at all. The dispersal of German carpentry methods in eastern and central Europe is very well known and well documented. This information is all readily available. Since you're stressing the importance of following local methods, you should appreciate why I want him not to get distracted by Scandinavian or English methods that have nothing at all to do with what he has. None of this is my own opinion, if you know German you can look at the documentation yourself. If he is guided by scandianvian practices, he'd use entirely the wrong kind of joinery and construct something not suited for the sorts of roof coverings and the weather in his region. Don't know how it is in Slovenia exactly, but the winds off the alps elsewhere would rip a Norwegian frame to pieces, asuming we're talking about something like stavlaft (otherwise, you're just talking about Fachwerk as it's been adopted in Scandinavia centuries ago)   

There is of course some regional difference, but the underlying principles are the same, and it's very familiar. 

[Don P]

Its all good, most buildings I work on fall into some "transitional" form partway between one type and another depending on the needs and methods of the time. I'm enjoying reading whether something strictly applies or not. If it had pigeons I would expect to find evidence in the corners and stuck in the crevices even if it was cleaned. I've found tobacco in the walls of an old farmhouse. A generation before they had grown it out in the fields there, leafroller insects has brought it in and left the clue in the walls.

Are the tie beams we see upstairs over walls or posts below or do they clearspan the building?

There is a drill that reads resistance as it bores a sample, that is one way to field test but not a common tool. But, an explanation, there is no such thing as dry rot. There is rot that has dried. Have these timbers been wet from a leak? Another thing that can destroy them is insect damage, are there signs of infestation, many exit holes and dust? In other words, hone in on that more, what exactly is the reason for rejecting the existing timbers? If they are shot do you have access to trees that long, it might be better to hew or chainsaw mill a timber or few and keep them original size.

[Chilterns]

After examining the artwork on the side of this building it seems to be ecclesiastic figures. I am not overly familiar with external decorative traditions in Slovenia but I have seen such things in Bavaria in places like Oberammergau (passion play) and so from a conservation point of view this needs to be recorded and if possible restored. Would this decoration provide a clue as to previous use ? To enhance remnant colors take a flash digi pic towards the close of daylight as this tends to highlight remnant colors. Do you have local building artists  who can advise further ?

I'm with Don re his recommendation to undertake further forensic examination on the timber that you suggest needs to be replaced.

A simple test that can be performed on a decaying timber is to use a scratch awl or a pen knife and see how far you can make this penetrate into the timber. If the decay or insect damage (frass) is just in sap wood then the temptation to replace same should be resisted. Trying to replace an entire wall plate would be quite intrusive with this potentially resulting in the loss of significant historic material. Much better to undertake a localised repair if possible or add strengthening plates if required. Some pics taken along the full length of this timber would be helpful.

Have you made a full set of dimensioned drawings of the roof framework and identified on same where you want to make repairs ?

What is the timber species ? Obtaining a 46ft hewn timber from a 100ft larch tree in that part of the world should not be impossible but following the line of an original timber that bends or deviates from the straight could be problematic and so once again maybe think about a partial replacement but only if really necessary.

The oldest recorded (written down) song in the world is "Summer is a coming in" with the manuscript for same being found in Reading Abbey, Berkshire, England (1261-4). It has a nice chorus line "Sumer is Icumen in, Loudly sing, cuckoo! and so maybe the first known reproduction of cuckoo noises is neither Swiss nor Bavarian. (see Sumer is icumen in - Wikipedia)

Cuckoo - Cuckoo !

Chilterns    

[jcalderera]

Don P, the tie beams are all located over walls.

Don P and Chilterns, I am studying up on decaying timber and will try to bring in professional help.  I will save what I can, which most likely will be more than I previously thought.  I think I got excited about a full-on timber framing project that I lost sight of the original goal:  Preserving a historic structure.

My neighbor (4 houses down) has a a sawmill.  I asked him about the biggest timber he could get, and he told me 8, maybe 9 meters.  Perhaps that is because the mill does not have the capacity to cut such a larger timber rather than his ability to acquire such a large timber.  If I hand hew it, maybe it is a different story.  Great idea!  I will ask again.  I can also ask other neighbors about it, virtually all of them have forest land around the village.  Might not be an issue, though, if I am able to save the original timbers.

Chilterns, The Cultural Heratige Association of Slovenia is aware of the artwork on the wall and will take care of restoring it when the time comes.  They actually found the artwork below the outermost layer of paint when examining the house.  They are very excited about the find.  The region we are in does not have any examples like this.   


Once again, thanks!

John

 

[jcalderera]

Aw darn, I forgot to thank D L Bahler for the literature in the previus post.  Thanks!!  Even without being able to read it, the diagrams are helpful.

[D L Bahler]

For the long "plates" simple lap scarf ties will work if you're not able to get long enough material. That would be the joint generally used in this case in other German-type frames. It has continuous support, so it doesn't really need to be a strong joint. 

As to the appearance of hewn or not, you can see near the beginning of the document I linked how a German hewing process worked. 

You hew the log to shape with a narrow-bitted axe called a  Schrotaxt, and work it down pretty much to dimension with this as  cleanly and accurately as you can manage. If it's rough hewn, you stop here. The quality would be fairly similar or even cleaner to what you find in many American barns. (German carpenters are an obsessive lot) But to get the really really smooth faces -almost like planed- they then go through with a Breitbeil -or in America sometimes they call this a goosewing axe- and this will give an exceptionally flat surface. I know this technique was used in Slovenia because I've seen the documentation of it and examples.

I have an Austrian made Breitbeil that I might have bought from Slovenia, though maybe it was Hungary. I have another hewing axe of a different family that I use as well -one came from Slovenia and the other from Hungary but can't remember which. Both Austrian made, one presumably in the 1800's, the other much much older. 

So to match the appearance of German hewn beams, unless they were left really really rough, you want it so flat and smooth it's almost planed in appearance. (The idea often was to get it so flat with the Breitbeil that layout was much simpler) 

Also typically timber would be cut in the winter at least 2 years before it is used, maybe even a lot earlier. The stems are hewn oversized and then seasoned for a couple years. This way it is known how they will move, split, etc. and the troublesome timbers can all be culled. This is also a big part of why you do not tend to see timbers in German buildings that are heavily twisted, split, etc. and when you do, you know you have a building that was erected in haste or of lower quality.
German scribing was greatly simplified by excessively preparing the timber first. Generally it is not desirable to have any noticeable reductions or housings that are not part of the joint design. The timber itself is made as accurate as possible (though it can never be made perfect, and even if you could it would move out of perfect within a matter of hours) and layout is executed with the plumb bob and square in a method that's not much the same as "french scribe".

You joinery will mostly be simple. Tenons tend to be maybe a length roughly half of the width of the adjoining timber, so 3 to 4 inches in most cases, rather than the long tenons typical in American frames. There are of course exceptions, such as through tenons for certain tying joints. The dovetail laps are straightforward to understand -to lay these out, you cut the brace first, then scribe the shape of the dovetail onto the adjoining timbers. You can google "verkämmung" to get an idea of how horizontal beams join together. This is something highly subject to regional variation -the exact sort of "comb" used is something you'll have to investigate and find out (though to the casual viewer there is no difference. The different shape in the finished joint is all hidden inside anyway) 
All joints will be drawbored, make sure to pay attention to what size pegs are used in the different joints -they were sized that way for a reason. 
When replacing the rafters, which I'm sure you will have to do as rafters on these old buildings tend to be replaced regularly, personally I would advocate replicating the original joint, but reinforcing it with a steel strap (rather than a timber screw) to tie the rafters in place. 

It surprises me actually that the frescoes are rare. In a lot of Catholic regions in Central Europe this is fairly common. Ticino, Grisons, and northern Italy this would not stick out as unusual. Could it be possible things like this were all stucco'd over and suppressed during the Tito era?  I obviously have no idea, just throwing it out there. I know many places in eastern Europe had much of their history forever erased by the socialists. 

I don't know how things are with conservation in Slovenia. The Swiss and Austrians take it very serious, and there are many fine carpenters that excel in it. In Switzerland it's always a joke that carpenters will spend moths renovating a castle or some historic building, then when they're done you can't tell they did anything! I remember admiring the medieval framing once in the roof of Spiez castle, and then seeing on the particular section I was looking at a date carved in the wood -that portion was partially a renovation done in the 1930's. You couldn't tell the old from the new! To me that is the bar for conservation -you shouldn't be able to tell when looking casually, but nevertheless you should still make it so those looking for it can find out what's old and what's new.  

[jcalderera]

I tried hand hewing a bunch of timbers last year to limited success.  The timbers were already seasoned for a few years, perhaps I can blame at least some of the imperfection on that?  I tried using a Breitbeil (borrowed from my neighbor) but had better success with an axe closer to a schrotaxt.  Despite the questionable quality of the finished product, I had a great time in the process!  What a stress relieving activity!

I practiced drawboring on a mortice and tenon joint, but I haven't tried on a lap joint.  I haven't found any literature on it either.  There may be something in the document you sent, but I can't read it.  Are there any special considerations?  

I have been researching the rafter joinery.  I feel this will be a big challenge for me.  Do you have any info about the calculations and layout of such a joint?  

The frescoes are not rare in general, just rare for my immediate municipality.  

The conservation in Slovenia obviously is not taken as seriously as with our neighbors.  I believe it is mostly a money issue but there is also a lack of interest in the general population.  My neighbors all think I am insane for wanting to save the house (they also thought I was insane when they saw me hand hewing timbers.  They all politely pointed out that there is a sawmill 200 meters away that could do all the work in a day). 

The house is protected and we are working with the cultural heritage association.  Unfortunately they can not provide us with much, if any, funding (although, its been a while since we have been in contact.....maybe its time to reconnect again, now that we are trying to move forward) .  I am trying to balance "doing the right thing in the name of conservation" with "how much of my own money do I want to invest in something that won't be very practical".   

[D L Bahler]

As far as investing your own money, you can't get more cost efficient than using hand tools, hand-hewing, etc. The trade off, of course, is the investment of a lot of time and how much is that worth to you? If you enjoy it, of course, that's not so big a deal. 

I'd have to study your joints a little more to tell you too much specific. The angles of the laps, things like that will be different from region to region. I'm not 100% sure how your rafter joints actually work at the moment either. This is all to say, there's not a whole lot of really specific advice in terms of actually executing the joinery I feel comfortable giving, in the context of preservation, without actually seeing it myself. I would check with the conservation association to see if they have any more specific information about the joinery practices first. 

The biggest thing working with the breitbeil - it's really meant to remove only a very little amount of material. Most of the work is done with other tools, and the Breitbeil is just the very final step of hewing. People often make the mistake of trying to do too much with it. All the work is done with the Schrotaxt, and if you're building a barn you don't even use the Breitbail at all. If you do too much with the breitbeil, it will dig in and mess everything up. You're just lightly scraping away the surface to clean up the tooling marks. Think of it as more of a finishing tool than a shaping tool. It's certainly different in its use than an American style of broad axe. 

This guy generally is quite good with the German style:
https://www.youtube.com/watch?v=s-ynWSGRCw4
See how he uses the horizontal scoring lines to work the face to smooth, very important to do so. It's also important that at the moment of contact with the edge of the axe, you pull it toward you. You want to gently slice the grain, not chop it. It is something that takes practice, and I wouldn't be discouraged if you don't succeed at first -especially with no one to show you how to do it properly. 

In German drawboring, you offset the holes only slightly, maybe a few millimeters. You're not really trying to pull the joint together -the tenons are too short for that to work- you're just trying to make sure the pegs themselves are tightly locked in place. To pull the joint tight, you make sure your joinery is cut precisely (In Switzerland, you are taught there is a tolerance of maybe 2mm) and the joint is pulled together with a windlass if it needs it. It shouldn't need it though. It should be snug enough you can tap it together with the wooden mallet. 

The dovetail laps are not drawbored. The shape of the joint itself pulls it together tightly. Mortise and tenon is where you drawbore. Nowhere else. 

[jcalderera]

I am studying all the elements of the house and trying to learn about them.  The flying purlin is being thrust outward and I am trying to determine the main cause.  I notice there are struts that work in compression, but they don't help against outward thrust.



 
 
 
 
Above is one of 3 struts.  It has a half dovetail on one end (other side of the strut, not seen in picture), but only a lap joint with not even a pin on the flying purlin.  Clearly it does nothing for outward thrust.  The other struts have slightly different joinery, but are also ineffective against outward thrust.
 
Are the collar beams is this design (seen below) typically enough to prevent outward thrust, and this problem is due mostly to a failure in the collar beams?  Or should the struts have different joinery that also tie in the flying purlin?  



 



 
Thanks,
 
John

Sorry if I misused the words "strut", "compression", "thrust", or any other term above.  Hopefully all concerned will understand my meaning.

[D L Bahler]

No, the collar beams do nothing for outward thrust. Their function, at least according to the German approach, is to tie the rafter pairs together to reinforce against unequal live loads (wind, snow) Also, typically, at the purlin the collar ties bear on the purlins rather than the rafters. 

Perhaps the issue with the thrust at the flying purlin is simply a matter of poor design. Like I said previously it's far more typical in this sort of roof for the purlin to be jettied out beyond the eaves wall, held by the extended ties. Almost always if you see a purlin arrangement like this, there is a fully supported ridge. A structural ridge eliminates outward thrust. In German you call a roof with a ridge beam "drucklastig" -drucken = "to press" because the rafters press the walls inward. To my eyes, the beam and joinery arrangement at the bottom implies "drucklastig", and if I'd see this without the rest of the structure I'd assume there was a structural ridge. 

I highly suspect there is a modified design here for aesthetic reasons, but maybe the carpenter  didn't have a solid grasp of the forces at work. 
It's also possible the design is patterned after  a roof with a structural ridge, and the carpenter thought he could get away with some things due to the small size. He was sort of right too, since the building has stood for so long despite the design flaw. To say it's a design flaw is also not to suggest the carpenter was stupid. He might have been fully aware of the issue, but also understood at this scale it's not a really big deal. Keeping in mind, he probably never imagined you'd be revisiting his work 300 years later. 

The simplest fix would be to run a steel cable from the flying purlin back to the purlin posts and pull the flying purlin back in. 

[blush]

What you have is a bit untypical variation of the "normal" slovenian house, who knows what the story behind it is. Maybe they were reusing roof members. The double plate design is a common thing here, like @Bahler said, you get to use smaller members and cut simple joints. For example https://www.etno-muzej.si/files/oc/teren_22/22_446.jpg another slovenian roof.

The fourth picture shows double seat cuts, where the plate also has seat cut chiseled in. Common thing in Slovenia, but I saw some pictures of guys doing it in USA as well.

I'm no expert, just a random roof worker. But it seems the design of the roof does not put any outward thrust on the walls, the force is "caught" in the connection between the tie beam and plates. Again, no expert, maybe i'm missing something.

Have fun renovating btw! And good luck with the family relations, coz this thing will take some time and destroy some nerves.

[D L Bahler]

Thanks for the informed regional perspective, that's great stuff!
As an interesting aside, what we are looking at in this picture is an example of what is one of the world's oldest timber framing traditions. 
Aside from the cultural connection through the Hapsburg rule and German immigration during that period, there are other very valid reasons to compare Slovenian architecture to examples in Austria, Switzerland, and the Black Forest -they're all part of the same Central European cultural region. The indigenous framing techniques in these regions are all derive from the Hallstatt (late Bronze Age Celtic, 12th-6th centuries BC) architecture, which themselves stem from much much older techniques. In Central Europe, the indigenous and ancient Alpine cultures assimilated the languages of later invaders (Romans, then Germans and Slavs) but their culture -including their architectural forms- remained mostly intact. 
So there are some aspects in these frames that are very familiar to anyone versed in this sort of architecture, but which I'm sure seem very unusual to people familiar with American, English, or French timber framing techniques. They have very very little in common in terms of their lineage. 

[jcalderera]

Thanks guys!

The failing collar beams/flying purlin is obviously not a good thing, but if I am to put a positive spin on it, it is that I am learning a heck of alot about roof structures and the forces involved.  

As an update:  My first plan with this renovation was to replace all members of the roof structure.  I was looking forward to it as a timber framing project.  I'm realizing this is kind of selfish.  Now, as I learn about and become facinated by the history of the structure and about timber framing in general, I am focused on saving everything that I can.  I see this as being more complicated, but it is definitely the right thing to do. I found an "old school" roofer experienced in historical structures who will come over and try to analyze which timbers can be saved and which ones need to be replaced. 

I don't look forward to matching new rafters and collar beams to the old seated lap joints!  At my skill level, I think this will  be very complicated and time consuming.  The amount of time is only an issue because this will need to be done after the roof is uncovered (at least as I imagine it), leaving the structure unprotected against the elements for longer than I hope.  Solutions to this are doing it in sections and having a good, easy-to-set-up tarp system, I guess.   

[blush]

Seat cuts and birds mouths are usually made simple and are all in the right angle, because of the slope of the roof. But your roof is a  bit off center, who knows

Maybe before the actual tear down make templates of the roof members. For example, take a wooden board which is the same width as is the height of flying purlin. Then you trace the outline of the joints on the board and cut out the joints. You end up with 1:1 template. With this you can at least prepare, replicate some members beforehand.  

And remember, construction is about "team work" (get a team so you won't be alone ).


@D L Bahler

I found out that there is not a lot of information about "central europe style framing" in english language. Most of the things you need to google under german names.

 

[Don P]

 From what I'm seeing I would call the rafter seat a step lap. If rafter thrust were causing the plate to tip outward I would expect to see those joints jammed tight and plate joint rotating outward. If I'm understanding inside and out it looks like the tie is overhanging the wall below, if the tie is dropping outboard then the joint could be loose and the plate rolling outward. It looks to my admittedly imperfect understanding of what is going on like the rafters may be balanced on the upper purlin. If so and if it dropped the roof can thrust on the plate. I'd first wiggle rafters at the plate, is that jammed tight or is it loose.