Page 1 of 5 1 2 3 4 5 >
Topic Options
Rate This Topic
#25255 - 01/20/11 05:46 PM Infill and Half Timbering *
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
I am working out the details of the enclosure of my shop, and need to decide between 2 different traditional styles. The first is a half timbered exterior and interior, the second is an infilled wall with a board clad exterior.

I like the look of half-timbering, but I have to wonder if it would be appropriate for my climate. I live in Central Indiana where humidity levels are quite high, it rains frequently, and super cell thunderstorms com by often with their heavy rains and high, driving winds. Half timbering was not designed for this climate, and I wonder if it would leave the frame too susceptible.

I would not use wattle and daub, it simply would not survive our weather. My infill would be a German style, using brick, stone, or clay/loam. It would have a generous coating of plaster inside and out. What I worry though is if the interface between infill and timber would attract too much moisture.

The wood is not going to be oak, rather it is going to be assorted locally available wood. This includes rot-proof species like cherry and walnut, but it also includes rot-susceptible species like hard maple and hickory. The timbers, however, will be thoroughly sealed and painted on all faces that may come in contact with moisture (it's a part of the tradition) The roof overhang is also very wide, so it will provide a good deal of protection.

I wouldn't despair if I had to abandon the half timbering and clad the frame with some nice boards, I like the all wood look too
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#25259 - 01/20/11 09:12 PM Re: Infill and Half Timbering
Gabel Offline

Member

Registered: 11/18/03
Posts: 687
Loc: Georgia
I love the brick infill look. Some nice examples in Old Salem, NC.

After a lot of research and thought on half timbered systems, my take is that whether you use traditional or modern materials and methods you're going to need to do thorough annual or at least biennial maintenance. Most folks won't keep that up and I can't say I blame them.

Let us know how the planning progresses.
_________________________
Gabel

www.holderbros.com

Top
#25263 - 01/21/11 08:18 AM Re: Infill and Half Timbering
TIMBEAL Offline
Member

Registered: 12/10/07
Posts: 1874
Loc: Maine
The term "half timbered" as pointed out by Ken Hume, I believe, refers to the timber being split in half and not necessarily the infill system. I like that explanation of half timbered as a better description.

Too bad we can't take the time to maintain a simple, down to earth system. I owe, I owe, so off to work I go.

What is the difference between clay bricks and wattle and daub? Are you planning on using fired brick or raw? Aren't they made from similar material? What makes wattle and daub inferior?

Top
#25265 - 01/21/11 08:58 AM Re: Infill and Half Timbering
mo Offline
Member

Registered: 11/04/06
Posts: 850
Loc: Charleston, SC
I find this thread interesting, and have many questions on it as well.

I'll just start with one though. smile

DL, when you talk about painting the surfaces that are subject to moisture, are you talking about at joinery abutments or the any face that is exposed to the weather? What does one do for say, exposed posts? Do you choose the best wood characteristics to expose to the weather? Is there some other protectant one applies to the timber?

Ok, more than one question.

Top
#25268 - 01/21/11 11:35 AM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
Mo, Look at some historic examples from Europe (Google Fachwerkhaus and Riegelhaus for German, and look at some English and French houses)and you will see that the entire exposed faces of the timbers are painted, usually a dark brown or a dirty red.

Wikipedia says the following regarding the term Half Timbered:
"One of the first people to use the term half-timbered was Mary Martha Sherwood (1775–1851), who employed it in her book The Lady of the Manor, published in several volumes from 1823–1829.
By 1842, the term "half-timbered" had found its way into The Encyclopedia of Architecture by Joseph Gwilt (1784–1863)."

It may have meant something else at one time, but this seems to be the understood usage now.

Gabel, just googled Old Salem. Sure are some nice examples. Did some research -the infilled structures were built by the Morravians, a German religious group. I thought the buildings looked German.

My ideas about wattle and daub being weaker are handed down to e from the Germans. It is said that part of the major influences for the development of Fachwerk was so that better materials could be used as infill. The claim is that daub cracks easily, is badly damaged by weather, and is cold and drafty. Brick and stone are said to be the best choices.

There is another infill choice that I have been studying a lot lately, and I think may be the answer I am looking for. It is called in German Bohlenwand or BohlenStänderbau or Ständerbohlenbau. Basically it is the use of thick boards or blocks placed between timbers, tied into grooves at either side.

nails are then driven into the boards on the outside face, and are covered with a coating of straw-clay to insulate and then with lime to waterproof.

This system, due to the boards being inset into the posts, does a good job of keeping out drafts.

Were the interface of board and timber sealed with tar or some such then water would not have the opportunity to penetrate.

This also gives for a very attractive all wood interior. Alternately the plastering can be swapped so that the exterior is all wood. There are a few examples I have seen where there is no plastering, but these tend to be drafty and uncomfortable.

Bohlenwand was invented in Medieval Switzerland to be a cheaper alternative to brick and stone houses.

pictures are from de.Wikipedia article http://de.wikipedia.org/wiki/Bohlenwand

a brief tour of European Half timbering vie Google Images:
France:


England:


Denmark:

Low German:

High German:



Hopefully that's enough to inspire...
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#25269 - 01/21/11 03:01 PM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
Eureka!

While thinking about the Bohlenwand technique I got inspired. And I think I have come up with a system that could work well for a modern house and be suitable for modern ideas of comfort.

In Europe the modern twist on Bohlenwand is to use special manufactured panels that are made of foam sandwiched between layers of wood. This is a good system and works well, but the only problem is we can't get those panels here.

So I thought of an idea. Instead of 1 single panel sandwich, what if there were 2 completely separate layers of wood each in its own key in the posts, and the insulation (preferably foam of some sort) is placed between these layers. It would look something like this:

or a plan for a plan drawing that makes the various aspects a bit clearer maybe:

This system, I think, has the potential to work better than the European version. The reason is that It can be tightly sealed quite easily.
The outer layer of boards should be the first to be put in. They would be standard 1x stock set back from the outside edge perhaps 3/4". It should be noted here that this is designed to be used in a close posted system, 3/4" boards are plenty stable over 3 or 4 feet but over 12' or more they would be far too wobbly and would require studding.
These boards would be plastered over on the outside with clay and lime to make the infilled panels flush with the outside of the timbers. On the inside spray foam would be used to seal off all of the joints from drafts.
The inner layer could also be 3/4 boards, but I think that thicker boards would work better. The reason is that it would allow you to take advantage of wood's thermal mass on the inside of the structure where it is the most beneficial. I have shown here 2x stock set back 3/4 inch from the inside face of the timbers. This would allow a little bit of timber exposure. Keep in mind though that any setback from the inside reduces the size of the insulation cavity, but a certain amount of setback is required so that the boards can have a channel to key into the posts.
The inside can use nice boards for an all wood finish, or you could use cheaper wood and coat with plaster.
The insulation layer can be just about anything; it could be cellulose, spray foam, foam board, straw, wool, shredded tires, or whatever you could dream up. You have a very large cavity surrounded on 4 sides by solid wood.
Part of the beauty here is that this system can easily take advantage of both thermal insulation and thermal mass. It can be easily adapted to different climates simply by changing the infill material and the width of the inside boards.
Obviously this is not going to be a super insulated house, but it's not designed to be. However, it could be with 1 minor variation. eliminate the outside layer of boards and replace it with foam sheathing nailed or screwed directly to the posts on the oustside (you may want a layer of wood or plywood for rigidity). This of course would not give you a half-timbered exterior however.

Now this is kind of a side track from my original question, which still stands. That question being whether or not a traditional infill system would be suitable for a shop building in Indiana's wet, stormy climate. My current line of thought is that clay based infills would be too susceptible to wind-driven moisture and high humidity, but that a Bohlenwand style wall with thoroughly sealed joints might do the trick.

As a side note, The use of clay on the exterior of the Bohlenwand seems like a very good idea to me, provided it is sealed by the plaster. This is because a silt-clay loam is highly hygroscopic (unlike pure clay) but does not retain high levels of moisture (unlike pure silt). This means it draws water more readily than the wood will, so it effectively keep the wood dry under normal conditions, and it at the same time will readily diffuse the water into the atmosphere after the moisture event has passed.


Edited by D L Bahler (01/21/11 03:02 PM)
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#25270 - 01/21/11 04:11 PM Re: Infill and Half Timbering [Re: D L Bahler]
Gabel Offline

Member

Registered: 11/18/03
Posts: 687
Loc: Georgia
Originally Posted By: D L Bahler

As a side note, The use of clay on the exterior of the Bohlenwand seems like a very good idea to me, provided it is sealed by the plaster. This is because a silt-clay loam is highly hygroscopic (unlike pure clay) but does not retain high levels of moisture (unlike pure silt). This means it draws water more readily than the wood will, so it effectively keep the wood dry under normal conditions, and it at the same time will readily diffuse the water into the atmosphere after the moisture event has passed.


Would the clay plaster have a lime plaster on top of it? Or at least limewash?

It seems that clay exposed to weather wouldn't last.

I do like the way moisture would be managed. I wonder if adding foam in the cavity would cause problems with that...
_________________________
Gabel

www.holderbros.com

Top
#25271 - 01/21/11 05:09 PM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
Yes the clay would be covered with lime, at least a finish coat to seal it all off.

I wonder the same about the foam. I don't think it should be a major problem though as it does not seem like water would make it that far.
I would be worried though about the foam holding water there in the case that moisture does penetrate that far.
If it is a major concern a heavy clay could be plastered on the inside in stead, but wouldn't be quite as air tight. Remember that the whole reason for the spray foam is to stop drafts. As such it COULD be considered an extra feature and is not absolutely necessary.

Right now I am trying to work out in my mind how the system would be executed around braces. One drawback is that this all has to be put in place as the frame goes up, before horizontal timbers such as plates top off the cavities. order of assembly suddenly becomes very important!
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#25272 - 01/21/11 05:37 PM Re: Infill and Half Timbering
Gabel Offline

Member

Registered: 11/18/03
Posts: 687
Loc: Georgia
I'd like to be able to make a system like this meet building regulations.

We've done one with a groove in the posts/studs/braces but instead of boards it had hardibacker - a fiber cement sheet product. And yes, it's tough to put in as the frame goes up.

We didn't groove the upper face of any braces, sills, or other horizontal or diagonal members. All of these had a bevel cut in them in the hopes that water would drain away from the panels.

The groove was wider than the panel's thickness and foam backer rod was stuffed in the groove and then a polymer chinking material was used around the perimeter of the panels where the panels met wood. The finish for the rest of the panel was typical stucco.

We didn't design the system and we only took it as far as cutting each panel and installing it as the frame was raised.

I haven't been back to see how it's holding up -- it's about a 12 hour drive from here -- but I hope to someday soon.
_________________________
Gabel

www.holderbros.com

Top
#25273 - 01/21/11 06:53 PM Re: Infill and Half Timbering
bmike Offline
Member

Registered: 01/09/08
Posts: 918
Loc: Burlington, VT
what material would you use that could be exposed to the weather - and not shrink tremendously, opening up issues of checking / vapor drive / and your seal breaking...
_________________________
Mike Beganyi Design and Consulting, LLC.
www.mikebeganyi.com

Top
#25276 - 01/22/11 11:53 AM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
Gabel,

When dealing with a half timbering system, I am naturally assuming that one will be copying some old world European style of building such as those pictured in a previous post. In this case the boards will have to interface with very long braces, and are going to have to be keyed into them. It does appear however that in the European Bohlenwand the planks are not keyed into any horizontal members, and the top faces of horizontal members, or at least the ground sills, are sloped outward to let water drain off.

I like the idea of the borads forming a 'floating panel' between the posts. They would be free to slide back and forth and so would not be compromised in any way by post movement.

On the subject of the foam anti-draft layer of spray foam:
I have thought about this, and decided that any sprayed or plastered on substance that is intended to resist draft is going to crack and break as the wood moves seasonally. What I am now considering instead is using housewrap on the inside of the cavity instead. It would stapled up against the outer plank layer, against the sides of the posts, and could wrap around into the rabbets for the from planks to ensure no draft gets through. Or, alternately, foam could be sprayed along the edge of the wrap on the post to do the same. The housewrap would be able to move freely with seasonal changes in the wood without loosing its seal, and it doesn't seem quite as risky concerning moisture issues as the foam.

Gabel you also mentioned about building regulations, that of course is the big question isn't it. What problems do you foresee that should be addressed?

The diagram I made uses 7" deep walls, leaving a 3-1/4" cavity for insulation. 3" of extruded polystyrene foam board would be about R-15, compared to a fiberglass which for 2x4 is r-13 and 2x6 is r-19. There is less thermal bridging in this than is a stud wall, and when you factor in the insulation and thermal mass properties of the planks and clay you will probably still come to an average of about r-15. I haven't done any real calculations, that's just a rough guess. This system would perform at least as good as a standard 2x6 stud wall, and of course making the posts deeper would push the r-value up even more.

I will do some figuring and put up an r-value comparison later
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#25277 - 01/22/11 12:29 PM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
The Figures are in:

The cavities have a total r-value of around r-18, actually slightly higher because I did not figure the value of the clay and plaster, and rounded down. This is the combined r-value of the foam board, 3/4" outer planking, and 1-1/2" inner planking

7" thick posts have an r-value of about r-8, slightly more for most softwoods, slightly less for hardwood.

I figured that the cavity generally occupies about 88% of the surface area of the wall, and the frame about 12%. For more complicated framing the frame may occupy as much as 20% of the wall area. 20% frame gives an average r-value of 15.5, 12% frame gives an r-value of 16.5. This is every bit as good as a 2x6 wall with no exterior foam insulation.

here is the formula I used:

a= average r-value
f= r-value of the frame
c= r-value of the cavity
The wall is divided into 20 sections, with each portion given its proportion of the 20, so the frame has 5/20ths of the wall area if it is 20% and the cavity would be 15/20ths

a=(5f+15c)/20, a=(5x8+15x18)/20, a=15.5
or
a=(3f+17c)/20, a=(3x8+17x18)/20, a=16.5

Not a super home by any means, but nonetheless a more than adequate insulator. Certainly meeting the prevailing standards.


Edited by D L Bahler (01/22/11 12:32 PM)
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#25278 - 01/22/11 06:26 PM Re: Infill and Half Timbering
dbailly Offline
Member

Registered: 02/18/09
Posts: 8
Loc: Berkshire County MA
DL,

I just wanted to through my two cents into the mix. First there is a timberframer here in Western MA who lives around the corner from me who is currently building a Half-Timbered shop. He has used tradition brick infil and it appears that the timbers have been treated with something. (Not to through Dave Shephard under the bus, but he might know a few more details as he helped raise the frame.) You mentioned that you were concerned about your effect of the local climate on the infil, well we are already over 5 ft of snow, we've had freezing rain and temps reaching 15 below zero. Plus July and August are filled with 95 plus degrees and 95% humity days. Of course no matter what you do you will have some maintenance, so I would say go with your heart. As for the interior finish and insulation why not combine the brick infill with the slotted board system. This would also leave an air space for the insulation of your choise. Good luck. Be sure to post pics when complete.

Dan

Top
#25279 - 01/22/11 10:18 PM Re: Infill and Half Timbering
TIMBEAL Offline
Member

Registered: 12/10/07
Posts: 1874
Loc: Maine
Out of curiosity, when we pour large concrete slabs there are control joint cut into the surface to control where the crack goes, this is due to the high rate of shrinkage. So I wonder if you were to apply the same theory to a daub wall and force the cracks to happen in specific places one could go back and fill these cracks later after it has dried. Otherwise it just shrinks willy nilly.

If my understanding is correct, bricks are small enough and independent of one another, as such, they do not shrink on a large scale. Similar to 2-1/2" wide hard wood flooring compared to wide boarding.

Top
#25280 - 01/23/11 12:18 AM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
Tim, That's a thought. But even still the nature of Daub is high maintenance. The difficulty lies not only in the fact that it shrinks as it dries, but that the formation of frost within causes the molecular structure to break down over time -the same affect that you use to your advantage when making any loam wall material as you leave the dirt to sit out in small piles over the winter so that the frost can break it down.

To alleviate this problem, clay bricks rely on the addition of sand and other aggregates. And many times the Loam wall systems are mostly straw and have very little actual clay in them. (This is not only true of the modern Lehmbau, but also of older techniques dating back to the middle ages)

About the issue of bracing on the bohlenwand:
The Bohlenwand is a major part of the Swiss tradition. In Switzerland the general practice is to have the planks sit flush with the inside of the wall, and the braces are then let in from the outside. These braces rely on lap dovetail joints. Alternately the planks are set in the middle, and thin braces are let in on both the inside and outside.

Example:


That image is from a very good book, the part covering Bohlenwand can be found here:
http://durm.semanticsoftware.info/wiki/index.php/Durm:Bohlenw%C3%A4nde

Browse through that book, It's incredible. Great pictures that show a lot.

Obviously let in braces will not work if the board are 3/4 of an inch from the edges of the timbers.

A possible solution, however, is to instead nail boards onto notches cut on the outside of the timbers (the timbers would have a cross section somewhat like a fat +) This would actually solve 3 problems at once, it makes it so that inserting the boards around braces and such is quite quick and easy, it makes it so that the boards can be inserted after the frame is raised, and it eliminates the problem of the floating boards moving relative to the top plate, which could cause serious plaster issues.
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#25281 - 01/23/11 06:48 AM Re: Infill and Half Timbering
TIMBEAL Offline
Member

Registered: 12/10/07
Posts: 1874
Loc: Maine
I would wonder what percentage of moisture it takes to saturated a clay/straw wall enough to cause freezing and thawing, in effect crumbling the wall. The walls are to be constructed in the dry season allowing enough time for them to dry before cold temps set in. I see a dry wall with protection very different than a pile of clay exposed and fully saturated with water.

I keep reading clay and loam being used interchangeably, just to clarify, I don't feel comfortable using loam. For some unknown reason, I can't put my fingers on, clay seems to be the better choice. So when I say clay I mean clay not loam.

Most systems require maintenance, it all depends on what level you feel comfortable maintaining the system.

At Fox Maple, Steve Chappell's place, I noticed they were using kerfs cut into the sides of the timber for the infill to key into, so when the shrinkage occurs there is some sort of blockage to keep old man winter a bay. These kerfs acting similar to the planks inserted as the frame goes up. I am sure that system is not perfect either.

Speaking of foam built into a infill wall system, as you point out frost building up within a wall could deteriorate the infill system leading to problems, as well. If the foam is not of sufficient insulating value, and there is moisture within the house trying to get out and moving into the wall system, it will hit the blockage of 1-1/2" foam board and build up. If the outside temps are sufficient enough to to freeze the moisture on the inside face of the foam, I see this as an issue to consider. This is just one of many scenarios. The point which I think has already been made, adding modern components to older technologies may have hidden consequences.

It is all ways fun to reinvent the wheel or at least attempt. If nothing else is reassures the old method still works the same as it always has, even with its, known, pit falls.

Top
#25283 - 01/23/11 12:03 PM Re: Infill and Half Timbering
Cecile en Don Wa Offline
Member

Registered: 08/08/09
Posts: 267
Loc: the Netherlands
Hello,
From what I read here, traditional infills are not normal in the work of timber framers writing regularly on this forum. That is interesting in and of itself.
_________________________
https://ernestdubois.wordpress.com/

Top
#25284 - 01/23/11 02:07 PM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
I would guess that 15% moisture content would be enough to cause trouble. In Indiana, things generally will settle at a moisture content at around 12 to 15% or so because humidity levels remain very high all year. If exposed to the hot and the cold I foresee issues.

Where it is normally employed these problems don't exist. In my travels I have realized just how harsh the weather in my home state is. Central Europe seems like a paradise when compared to the Midwestern US.

In Fachwerk, the infilling tradition I am familiar with, the bricks are keyed into channels in the post. Also the frame is designed for infilling, the posts not being any larger that 4 or 5 inches wide will not shrink much and so won't cause large gaps.

About reinventing the wheel, well it should be noted that the wheel has been reinvented many times over the past several thousand years. It has been advanced and made better. A few notable examples being the invention of the spoked wheel, and the pneumatic tire, and the wheel bearing.

In other words, there is absolutely no reason why we can't improve on old ideas. We need to adapt them to modern conditions, or else just watch them fade away entirely. The Swiss probably wouldn't use the Bohlenwand at all today if someone hadn't figured out a while back how to insulate it.

Now we can't do that haphazardly. Our innovations need to be well thought out and carefully managed. That's why we talk about them here, and I certainly value your input. But I just wanted to step up and say, there's nothing wrong with wanting an infill system that also performs well by modern standards of living. If you want people to actually spend their money on them, then that is a necessity.

Of course there are a few issues that need to be worked out, after all I just thought of the idea two days ago.

As for the boards moving up in down in the channels and causing plaster problems, I thought of a simple solution to that. After they are in place where they need to be, secure them with a single nail on either end. That way they can still expand and contract without creating a huge gap at the top of the wall or destroying the plaster or cracking. If supporting plaster these boards should probably be no bigger than 1x6, with 1x4 probably best (any smaller would be too wobbly). For the inside where the wood is exposed, the Swiss solved that problem. A trim board is attached at the top to the frame but not to the planks, hiding any gap that may form.

Don, I know what you mean. Traditional infills haven't seen much exposure in the US. Although many people I have shown pictures to have expressed some interest in the concept -the visual affect cannot be matched.


But back to the topic of my Shop.

My current plan, I think, is to go with a traditional Bohlenwand technique.
Part of the intention of my design is to replicate the style of building that is to be found where my Family comes from, Wattenwil Switzerland. So with that in mind I am considering doing a Bohlenwand with exterior let in braces, complete with richly carved timbers inside and out.
But I am tempted to try out my concept to see how well it actually works. Decisions decisions...

I like the way the all wood houses are decorated. That's a major plus for me. The major disadvantage of course as that a purely traditional infill has just about no insulation value whatsoever. But by using lots of big wood on interior walls the houses built this way are still quite cozy in the winter. The Kachelofen I think helps too.
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#25294 - 01/24/11 12:11 AM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
something should be said of the way European infilled structures are designed. THere are, I see, 2 major classifications that might be used.

The first is the use of a frame designed specifically for the purpose. This would be like the German Fachwerkwand, where the entire framing system is originally designed around the use of brick and stone infills.

The other is the use of an all purpose frame modified to support infill. Basically this would be a studded timber frame where the weight of the structure is born by a few large timbers with small studs between them. This seems to be the prevailing style of England and France.

Which style is better? Well who is to judge> Both have proven themselves. The Germans claim that the true half-timbered frame originated with them and spread to the rest of Europe, this meaning the frame designed to support brick and stone instead of wattle and daub which is generally considered to e inferior by the Germans.

It is also important to note 1 thing about the infill. The Germans say that you should never expect the brick, stone, or whatever to have any structural properties whatsoever. You should not expect the infill to bear any of the roof load, or stiffen the frame, etc. even if it is made of high quality brick or well crafted masonry.

I have to ask about wattle and daub. If you have a frame system clearly designed to support an infill why bother with it?

The advantage of wattle and daub is that it can be made to cover as big an area as needed. You can build a house with a few posts and then set a series of stakes to build your wattle on, and so forth. Such is how early medieval houses were built.

But in Germany the half timbered structure was invented to get rid of the wattle, and use better materials instead such as brick, fired or unfired, and stone or even wood. I can't say for the development in other countries, as Germany is what I have studied, but I imagine the reason is similar.

So what would be the advantage of using wattle and daub? The Germans in the later middle ages occasionally used it to fill interior walls because it is obviously cheaper than nice bricks, but never trusted it on the outside.

The big advantage of bricks is that once they are there, they are there. They have been made in such a way that they are not going anywhere, especially if they are fired bricks.

The Germans have the following wisdom to offer on earthen wall materials:
The best material to use is a mixture of clay, silt, and sand. Too much sand makes it too lean and it crumbles, too much clay makes it too fat and causes it to crack and break apart. Straw is added and is not expected to serve as aggregate, but to alter the density. The addition of manure makes it stronger because of the mineral composition, also horse manure works the best as it has undigested cellulose fibers in abundance. Lime added to the mixture neutralizes acids in the mischt and produces preservative salts.

With all this, though, the general consensus among most Germans seems to be that brick is the best suited material for infill, and after that is stone. The infill is usually covered up with plaster at least on the outside, and often on the inside as well. The biggest reason would be that by so doing you can use cheap bricks, such as those from the outside of the old style kilns that aren't fired as well and have black all over them. The lime plaster covering protects the cheap bricks which would otherwise deteriorate quickly, and also hides their ugliness. In modern usage, this means you could go to a brickyard and buy their left-over bricks, bricks that were sent back as extras from orders. They are generally quite a bit cheaper and mismatched. but that doesn't matter if you are covering them up!

In France, it seems that in many cases instead of plaster gypsum is used. There is, after all, a reason why gypsum plaster is called plaster of Paris, as it used to come from mines in France.
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#25299 - 01/24/11 09:20 AM Re: Infill and Half Timbering
bmike Offline
Member

Registered: 01/09/08
Posts: 918
Loc: Burlington, VT
I'm still wondering what wood you'd see as optimal for this. Shrinkage and checking, as well as potential rot, water damage, and vapor drive would be issues to me... especially in a modern residence with lots of potential moisture coming from inside the house, and dramatic swings in temperature.
_________________________
Mike Beganyi Design and Consulting, LLC.
www.mikebeganyi.com

Top
#25303 - 01/24/11 10:37 AM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
Wood will function better than clay in relation to temp and moisture swings, provided you accounted for that in the beginning.

The best thing to do is the allow the planking to do what it wants to. don't force it to do what you want it to, it will win. That's why you put the boards in channels, so they are free to move up and down and side to side if they want. And they do want to. That's also why you use narrow boards. I am thinking 1x4 for anything expected to support plastering, just to resist cracking.

One thing that you can easily do to prevent the ingress of moisture from the inside is to use an old technique, seal the cavity-side face of the inner planking with tar or some other sticky water proofer. But do not DO NOT use a vapor barrier as this will just hold the moisture against the wood, which is BAD.

The inner planking is no different than using boarding on an interior wall. The outer planking is essentially the same as plywood sheathing. The benefits of clay are not to be underestimated either.

The wood species used can just be common pine. Or it could be cedar. I would be afraid of using hardwood in most cases because of cost and stability.

If you are still scared of moisture travel, plaster the inside with clay. That will stop it right then and there.
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#25338 - 01/26/11 05:35 PM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
Again on the subject on moisture intrusion from the inside.

There is one technique that is by no means modern and has been used in various countries where a plank infill has been employed to stop drafts and moisture travel. In this case, the thick plank is instead replaced by two thinner planks and in between them a layer of some type of wrapping is placed, traditionally this has been paper or linen soaked in tar or blubber, but today we could use a modern house wrap or plastic for the same purpose. In my dual plank system, the inner 1-1/2 plank could be replaced by 2 3/4 planks with a barrier between them.

In The Swiss Bohlenwand, there are at times 2 layers of planks with the cavity filled with sand. This as a favored construction technique for old prisons as the sand would deaden any sound and also produce a dense, hard to break wall.
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#25627 - 02/24/11 12:22 AM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
I have been considering the moisture issue of this system some more, and am concerned. As of right now I intend to use the double plank wall system I have designed for my shop with a natural wood interior and plaster exterior, with exposed frame inside and out.

My biggest concern is that the posts will sweat where the boards are joined into them. This would give great occasion for both the boards and the frame to rot. The greatest concern I have is for interior, rather than exterior, moisture.

The following things I have decided:
1. Abandon the foam skim coat inside the cavity. In this case I think that this would just trap moisture and facilitate rot. The wall should be able to breathe to a certain degree.

2. The clay and plaster on the outside should be more than enough protection for the planks as far as keeping moisture out.

3. Before the outside is plastered, some sort of flexible seal strip should be put into the channel to protect this region should the plaster gap around the posts (which it certainly will) This could be a modern material, or an old-fashioned material like cordage soaked in tar (I doubt I can get whale or seal blubber for the purpose) This idea inspired by old ships, which had the gaps between the wooden planks sealed thusly.

Now what I need to do is figure out how to prevent moisture from condensing around the posts, and how to generally prevent rot in this region and on the wood as a whole.

The best solution I can come up with for the first problem is ventilation. The old Bohlenwand houses in many cases have the original planks that have stood there for in some cases over 400 years, often totally unfinished and unprotected -and generally made out of Swiss Pine, not German oak. The reason I think is that moisture had no real reason to gather there, it had plenty of opportunity to go elsewhere. On the old farmhouses the attics were wide open, because they were used to store the hay. plenty of ventilation there. The moist air could escape between the floorboards and up into the attic.

Now obviously a modern home needs to be a little bit tighter than all this, or at least the average homeowner would want it to be. But with a well and cleverly ventilated house I think the problem could largely be alleviated. But I think that if there was adequate ventilation in key areas such as along the walls, heat loss could be minimized while allowing moisture to escape. A well ventilated attic would be needed for this to work, I doubt an open ceiling with exposed trusses would be very good here.

For the second issue, there are two things I could think of that might help a great deal:
1. The wood on the inside of the cavity is thoroughly sealed with tar.
2. The wood on the inside of the cavity is thoroughly covered with plaster or a lime wash.

The first approach would seal off the wood from moisture, while still allowing it to breath.

The second approach may allow vapor through, but the plaster would make it very difficult for mold or fungus to grow and rot the wood.
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#26211 - 04/15/11 03:54 PM Re: Infill and Half Timbering
Housewright Offline
Member

Registered: 02/16/06
Posts: 332
Loc: Waldoboro, Maine
D L et al.;

Thanks for the eye candy (photos).

As I understand it bohlenwand translates simply as "plank wall", and the page from the book you posted shows both vertical and horizontal types of plank walls. Does bohlenwand have a specific meaning or is it a general term for different types of plank walls?

The Bohlenwand method of building with a single thickness of horizontal planks is also found in many parts of Europe, mostly Sweden, Jutland and part of Germany. I have an opinion that horizontal plank wall buildings are found in areas where Vikings settled. They are called a bulhus in Danish as one example, and are thought to have been brought to North America by the French known (with many variations) as "Pièce sur pièce". The oldest example I am aware of was found in excavations in Poland dating about 5,000 years ago but these used a V instead of a rectangular groove to capture the plank-ends.

This is an interesting idea to use two horizontal layers infilled with insulating material. Two thoughts I had looking at your drawing are to make the posts thick enough so you could leave small air spaces between the insulating and wall materials in the walls and to be sure the insulating material can be thick enough so condensation could not form inside the wall, but you have already addressed the moisture issues. Another thought for the non-traditional among us is that our forefathers used planks in grooves to avoid the high cost of nails. Now with cheap Chinese nails, the planks or boards could be nailed on rather than being fitted in grooves. Maybe the outside layer could be done using the "rainscreen" concept so the wall was ventilated.

I noticed at the last TTRAG conference that even the most experienced framers are still struggling with how to enclose a frame with our historically "modern" problem of heating, cooling, utilities, etc.

Now to be a smart a--, if you fill the walls with earth and use a sod roof is it an under-ground, timber-frame house?

Jim
_________________________
The closer you look the more you see.
"Heavy timber framing is not a lost art" Fred Hodgson, 1909

Top
#26212 - 04/15/11 04:46 PM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
Jim,

Yes, it does mean 'plank wall'

The Bohlenwand is common in alpine and sub-alpine regions, and takes on a number of forms. The alpine method is generally to have horizontal boards.

From what I know of the Scandinavian practice, I think you are right. There was an old Viking age and early medieval technique that was very similar, only placing the planks vertically. There are many fine examples of this technique that have survived into the present day, the Norwegian Stave Churches. The Urnes Stave Church in particular, since it dates back to about 1050, or the very end of the Viking age. This technique is called Stavverk, or 'stave work'. It has a timber frame with planking caught in grooves cut into the sills, plates, and posts.

This technique is probably how the better houses and farms were built in forested areas populated by Norsemen, with the poorer houses having walls filled with waddle and daub.

----

as for nailing instead of grooves...

I had considered this idea, and came up with only 1 solution that seems suitable, which is the first nail a piece of wood to the posts, and the nail the planks to this piece of wood. I do not think it would work to nail the planks directly to the posts, as they would barely be supported that way.

This solution is not without its problems however. The extra wood takes up insulation space, and creates a few more seams for water to collect and cause damage.

In addition, the groove does more than just hold the planks in place. It also stops drafts, and hides movement. I would suspect that if the planks were nailed to the edges of the posts, expansion and contraction would cause the nails to pull out over time. With the grooves, the wood is all allowed to move up and down and side to side as much as it wants.

For most projects, there is no need for timbers exposed inside and out. The double plank wall is designed for this particular situation. Today in America frames are typically exposed only on the inside, in Europe in the past frames were often exposed only on the outside. It is also common to have frames completely covered inside and out (which is the simplest to enclose)

Personally I think having 8" of timber jutting into your living space is a bit silly. (oops, did I say that out loud?) and I much prefer the look of a barely exposed timber, which is either flush with the inside wall or sticks past at most 1". The bohlenwand is really the ideal method of accomplishing this, the planking could simply be a means of supporting drywall or plaster, or form an attractive wood interior wall.

If you don't want timbers exposed on the outside, then this system lends its self readily to numerous insulating techniques. Just have an inside plank wall, and enclose the outside wall in one of many methods.

and to your last comment, look at Icelandic turf houses, and you tell me!
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#26213 - 04/15/11 04:59 PM Re: Infill and Half Timbering
Housewright Offline
Member

Registered: 02/16/06
Posts: 332
Loc: Waldoboro, Maine
I was taking a look at the Handbuch der Architekture D L provided the address to earlier and thought I would quote the machine translation regarding the infill materials:

"As a filling agent use: hay, straw, woody parts, tan, straw, sawdust, wood wool, wood shavings, peat, soil, sand, ashes, charcoal, kieselguhr or diatomaceous earth, slag wool."

and the original text:
"Als Ausfüllungsmittel benutzt man: Heu, Stroh, Schäbe, Lohe, Häcksel, Sägespäne, Holzwolle, Hobelspäne, Torfstreu, Erde, Sand, Asche, Holzkohle, Kieselguhr oder Diatomeenerde, Schlackenwolle."

The book goes on to discuss the suitability of some of these materials. Great book!

Thanks;
Jim

p.s. I'll bet the Icelandic houses are cool and damp, but "way cool" in my opinion.
_________________________
The closer you look the more you see.
"Heavy timber framing is not a lost art" Fred Hodgson, 1909

Top
#26215 - 04/15/11 05:25 PM Re: Infill and Half Timbering
Housewright Offline
Member

Registered: 02/16/06
Posts: 332
Loc: Waldoboro, Maine
As for the use of horizontal plank infill in timber frames in NE Europe check out this site showing a reconstruction of a boat shed using the "bul-teknik" like i mentioned earlier (bulhus, translates as "bole house", bole as in the trunk of a tree from the original plank material of split tree trunks rather than planks). This Stavgard looks like an interesting place.

http://www.stavgardgotland.com/husen.htm

In Sweden the horizontal plank method is skiftesverk which translates as "shift work" possibly relating to the planks shifting or sliding into the grooves.

http://sv.wikipedia.org/wiki/Skiftesverk

Jim
_________________________
The closer you look the more you see.
"Heavy timber framing is not a lost art" Fred Hodgson, 1909

Top
#26216 - 04/15/11 05:41 PM Re: Infill and Half Timbering
D L Bahler Offline

Member

Registered: 05/17/10
Posts: 946
Loc: Indiana
In Switzerland, they also have what they call Fleckenwand, which can also be classed as bohlenwand in some ways (and sometimes is called that)

Fleckenwand might be the evolutionary step between a post frame and a log building. What it is is large timber corner's and posts now and then, with thick timbers as big as these posts stacked in between them, and grooved into them. From this, people develop the complex corner joints and abandon the posts altogether, and end up with Blockbau.

The Buhl of Danish and Bohl of German are probably from the same root word.

Before saws were plentiful, planks would indeed have been made by splitting out a tree trunk...

Bole, from Old Norse Bolr- tree trunk...
_________________________
Was de eine ilüchtet isch für angeri villech nid so klar.
http://riegelbau.wordpress.com/

Top
#29806 - 11/20/12 08:28 PM Re: Infill and Half Timbering [Re: D L Bahler]
Hylandwoodcraft Offline
Member

Registered: 03/23/11
Posts: 141
Loc: Western NY
To revive an old thread... I am talking to an architect about building a half timbered house, possibly with SIP infill. The ply facings of the SIPS would be grooved into the beams, with a gasket material applied to the inside of the grooves to prevent excessive air infiltration. One of my considerations is wood species. I think cedar would be totally ideal, but not within budget. My local options that I was considering would be white pine or white oak. White oak would have rot resistance but high shrinkage. White pine the opposite. What does everyone think?

Top
#29808 - 11/21/12 05:09 PM Re: Infill and Half Timbering [Re: Hylandwoodcraft]
timberwrestler Online   content
Member

Registered: 11/07/05
Posts: 268
Loc: Becket, MA
White oak for sure. Heartwood only. Look at all of Europe.
_________________________
www.uncarvedblockinc.com

Top
#29811 - 11/21/12 08:21 PM Re: Infill and Half Timbering [Re: timberwrestler]
TIMBEAL Offline
Member

Registered: 12/10/07
Posts: 1874
Loc: Maine
Exposing the outside of a timber to cold while the inside is extra warm has always bothered me. The original half timbered building didn't have our heating system of today. Use a durable species.

Top
#29812 - 11/21/12 08:41 PM Re: Infill and Half Timbering [Re: TIMBEAL]
Hylandwoodcraft Offline
Member

Registered: 03/23/11
Posts: 141
Loc: Western NY
Yeah, I think you are right, the white oak is the way to go. That is a good point about the heat difference TIMBEAL. I like the idea aesthetically of doing the half timbering. I do however want to make sure I think it through fully. There don't seem to be many modern timber framers doing it, perhaps because of the obvious difficulties. It seems like some of the issues, such as the heat difference, would be ones that log home people have dealt with. I'll keep updates coming if the project goes through.

Top
#29814 - 11/21/12 09:33 PM Re: Infill and Half Timbering [Re: Hylandwoodcraft]
bmike Offline
Member

Registered: 01/09/08
Posts: 918
Loc: Burlington, VT
As i inderstand it, with the temp and humidity differences you'll likely get vapor drive, which will trap water where the dew point is, likely inside the wall.
_________________________
Mike Beganyi Design and Consulting, LLC.
www.mikebeganyi.com

Top
#29816 - 11/22/12 02:25 AM Re: Infill and Half Timbering [Re: bmike]
D Wagstaff Offline
Member

Registered: 02/17/12
Posts: 246
Hello,

Still being done as a matter of course here in places like France and Germany, Denmark, Belgium. Those are a few places I know of where no one would blink about it, plus more. Though I don't know anything about this kind of infill you mention only brick, clay block, the old time wattle and daub.

Greetings,

Don Wagstaff

Top
#29817 - 11/22/12 11:13 AM Re: Infill and Half Timbering [Re: bmike]
Hylandwoodcraft Offline
Member

Registered: 03/23/11
Posts: 141
Loc: Western NY
Mike, that makes sense concerning the vapor drive. I wonder how big an issue that really is... it seems like most stud frames with no insulation on the outside of the studs would be in the same boat. The same with log cabins. I'll have to do some research on whether that has ever been a significant issue.
Like D Wagstaff pointed out, they do it in Europe. I'm sure that they have retrofitted many old frames to be more efficient. Does anyone know of good literature from across the pond? I guess that weather conditions in Europe further inland would be fairly analogous to the north eastern US.
As far as the infill material... It seems to me that using a SIP might be less likely to cause problems than a brick or stone infill. It seems like they might be likely to condense moisture in a heated house, like Mike pointed out. If I use a SIP, the plywood facings would be inserted into grooves in the timbers. At least that would be wood on wood.
I am also looking into the possibility of using black locust for the timber. Now that would be a timber what would last a spell cool!
Perhaps half timbering doesn't happen much over here because we're just not used to it. It would be interesting to get some more European input to see what the comfort level is.

Top
#29818 - 11/22/12 12:01 PM Re: Infill and Half Timbering [Re: Hylandwoodcraft]
bmike Offline
Member

Registered: 01/09/08
Posts: 918
Loc: Burlington, VT
A big difference in traditional infill and your idea is that traditional materials tend to be all hygroscopic to some extent. SIPs are not, so the weak link is the joint between the timber and panel. It is my understanding that this is where the vapor drive will occur, exacerbated by the differences in materials and complicated by the inability to really seal a shrinking, moving material (green timber) vs. a dry stable material (SIPs).

When using conventiomal materials for enclosure I try my best not to run timber from inside to out, to avoid this issue. Especially with high heating demands and water demands - cooking, bathing, etc. can throw a whole lot of moisture into a house, and depending on season and location and ambient humidoty this may want to work its way out, condensing as it moves.

Of course using traditional methods may work just fine, depending on lots of factors.

But I'm not anywhere near an expert on the science, so consult with someone who is skilled in enclosure systems in your climate.

Top
#29819 - 11/22/12 04:17 PM Re: Infill and Half Timbering [Re: bmike]
D Wagstaff Offline
Member

Registered: 02/17/12
Posts: 246
Hello,

Yes, the basic incompatibility of the materials is what's at hand.

I don't know what it would take to get readers from here who are more expert than I am to pipe up, believe me they are looking in. Probably understandable language barriers though, in their defense.

Greetings,

Don Wagstaff

Top
#29824 - 11/23/12 08:15 AM Re: Infill and Half Timbering [Re: bmike]
Hylandwoodcraft Offline
Member

Registered: 03/23/11
Posts: 141
Loc: Western NY
That's really the problem I have had. I haven't really been able to find anyone who is really well versed in the science of enclosure systems. It's been fairly frustrating, and has necessitated a lot of research on my part to try to educate myself.

Most architects,engineers, etc. that I have tried talking to just don't seem to be that educated on anything but out the box approaches. I should keep on looking though.

I think I can effectively seal the joint between the timber and the panel. If I use a PVC weatherstripping in the grooves cut in the frame for the panels to inset. The PVC has a high rate of repeated compression recovery. If I use a 3/4" thick gasket and initially compress it, the timber could shrink and move quite a bit without losing the seal. The PVC is a closed cell weatherstripping, I could also use an open cell polyether weather stripping. Maybe the open cell would tend to let water vapor move more than the PVC.

Top
#29826 - 11/23/12 12:10 PM Re: Infill and Half Timbering [Re: Hylandwoodcraft]
TIMBEAL Offline
Member

Registered: 12/10/07
Posts: 1874
Loc: Maine
Sounds like assembling the frame could be a frig. Sips are very much an in the box approach. The installation of them sounds out of the box.

Top
#29827 - 11/23/12 12:39 PM Re: Infill and Half Timbering [Re: Hylandwoodcraft]
Jon Senior Offline
Member

Registered: 05/04/11
Posts: 112
To seal the joint I would recommend Compriband HPE or an equivalent (based on its intended use, not a promotion). Basically it's a pre-compressed impregnated foam strip that expands to fill the space. It tends to have a wide range of usable thicknesses and will continue to expand and compress as necessary into the future as the wood shrinks and expands. It's permeable to water vapour, but not to water so will prevent rain ingress while allowing the joint to breathe which should prevent condensation within the joint.

Its intended use is sealing the joint between the windows and the frame in timber frame (stud frame) buildings.

As others have pointed out, traditional infill materials tend to be more breatheable than modern ones. I've seen new constructions here (Normandy, France) using cellular concrete blocks (? Béton cellulaire in French). TBH I'm not sure that many builders actually care enough about the longevity of the building to worry about it and repairs are often made with cement mortar instead of lime.

I've been giving the matter some thought recently and hope to have more suggestions soon.
_________________________
Jon

Contemporary Norman longhouse in Normandy

Top
#29828 - 11/23/12 02:51 PM Re: Infill and Half Timbering [Re: Jon Senior]
Gumphri Offline
Member

Registered: 01/18/08
Posts: 83
In northern climates it is a big issue. I'm not sure we really understand the science of it. Where I live even the location of the vapour barrier is in review. I've seen several different routes for sealing joints between different materials on details where new and existing buildings joined.

These are what I view as the issues that need to be addressed with the joint
-the outside needs to keep moisture out
-the vapour barrier needs to be located in the correct location for your climate
-any vapour that does condense needs to have an escape out of the wall.
-the joint has to accommodate for movement in the timber.

I think if you are set on having timbers exposed on the inside and the outside you are on the right track with the expanding foam strips.

Another question is how do you plan to heat this home? Might a breathable wall infill made of log or straw better suit your needs? There are also wood fiber and OSB SIPs available near you.
_________________________
Leslie Ball
NaturallyFramed.ca

Top
#29830 - 11/23/12 06:47 PM Re: Infill and Half Timbering [Re: Gumphri]
Hylandwoodcraft Offline
Member

Registered: 03/23/11
Posts: 141
Loc: Western NY
Gumphri,
I need to get some more details from the architect as far as the heating/cooling details of the house. I'm assuming that the wood fiber sips you mentioned are Stramit panels, made from wheat straw. I make my own insulated panels for my houses, so I could conceivably use Stramit panels and laminate them to ply or osb.
I've been interested in Stramit panels for a while. I would love to use them in a project.
It looks like the weatherstripping that Jon Senior mentioned is basically poly ester foam. I think that if done right that foam would do let any possibly trapped moisture move out. I suppose that in my climate any problem moisture would originate from inside the house.

Top
#29833 - 11/24/12 03:57 AM Re: Infill and Half Timbering [Re: Hylandwoodcraft]
Jon Senior Offline
Member

Registered: 05/04/11
Posts: 112
@Hylandwoodcraft: The weatherstripping is a polyurethane foam impregnated with resins (direct translation). If you are aware of alternatives that serve the same function I'm interested as I'll be installing windows early next year and would love to find a cheaper alternative. Currently the weatherstripping is running at about 25% of the cost of the windows themselves!
_________________________
Jon

Contemporary Norman longhouse in Normandy

Top
#29835 - 11/24/12 03:54 PM Re: Infill and Half Timbering [Re: Jon Senior]
Hylandwoodcraft Offline
Member

Registered: 03/23/11
Posts: 141
Loc: Western NY
OK. So it is a bit more than just polyurethane foam. The website I pulled up on the product you mentioned was all in French, so I couldn't tell the specifics. There are a lot of products on www.foamtapes.net . Wow, 25% the cost of the windows is pretty significant. Let me know what you think of the products at foamtapes.net, their prices are really reasonable, if you can find something comparable.

Top
#29838 - 11/25/12 11:40 AM Re: Infill and Half Timbering [Re: Hylandwoodcraft]
D Wagstaff Offline
Member

Registered: 02/17/12
Posts: 246
Hello,
A pretty fragmented story seems to be emerging. There is another conceptual model that might be useful though not really widely grasped yet especially among architects and that is a systems approach. Instead of looking at individual components in isolation, site, frame, infill, roofing, sealing, insulating, heating, air quality... why not look at how all these things interact more intensively. I mean to say, it is really getting back to a rational approach.
We imagine wanting to improve on shortfalls of the way a half timbered frame has evolved and begin with the interface between the frame and infill where those openings develop and supposedly let the air in. So we seal everything up. It is the cause of two main unintended effects. A moisture build up and retention within the frame and reduced air circulation inside. Not only is the inside climate negatively impacted but the seeds of self destruction are planted within the very core of the building. I think the second law of thermodynamics is doing fine without any extra help, thanks.
What about an appropriately integrated shell of timber and say clay brick, for example - only because this is in between the two extremes of kiln fired brick and wattle and daub - which can be permeable on all counts, it will not seal the inside off so there will be a constant and desirable exchange leading to more efficient warming of the inside air - trapped motionless air constantly takes on and holds moisture becoming harder to warm - through a centrally located radiant heat source, the thermal mass of the walls will even out seasonal fluctuations of temperature and humidity for example as it regulates or maintains the ambient room temperature. The ambient temperature is what is important because it is what people in the room experience. The ambient temperature is the average temperature of all the combined exposed surfaces of the space. A final influential factor is the micro environment where the building is situated which can be planned appropriately. You see how it becomes difficult then to think about the infill only.

Greetings,

Don Wagstaff

Top
#29839 - 11/25/12 12:41 PM Re: Infill and Half Timbering [Re: Hylandwoodcraft]
Jon Senior Offline
Member

Registered: 05/04/11
Posts: 112
I've managed to track down an equivalent product in the US market (foamtapes stock Lamatek products and they don't appear to manufacture an equivalent); Schul Sealtite. There may be others but I've not found them yet.

DL Chemicals Topband & Pressband and ISO-CHEMIE's ISO-BLOCO 600 are products that have English language datasheets if you want more information on what they do.

The crucial differences between these types of products and those offered by foamtapes are:

Pre-compression - Very high compression to ensure that the joint can be fitted during installation without damage and that post-installation, the gap will be effectively filled.

Large range of working thickness - Ensures that the joint can cope with movement in one or both of the surfaces.

25% of the cost of the windows is for the HPE version which is a funky, designed for timber frame product. The narrower versions which don't offer quite the same thermal insulatative properties are much cheaper.

I've seen people using Neoprene gaskets to fulfill some of the joint sealing applications offered by these tapes (Bensonwood use them for sealing their wall units together and to the floor), but I think it's the permeability to water vapour and gap-filling qualities that make them interesting. There are versions that have a working range of 24-42mm (~1" - 1.5"). That's quite a gap to be able to reliably fill!

All in, on paper, I'm very impressed with these tapes. How impressed I am once I come to install our windows remains to be seen! :-)

Edit to reply to Don Wagstaff

In principle I agree, but the reality is that an airtight house will always be easier (read, use less energy) to heat and cool to a given temperature, than a leaky one. Relying on permeability of the walls to provide appropriate air exchange is unlikely to be successful, and using traditional window vents means that window placement becomes critical for air exchange. Managed ventilation (mechanical ventilation or even appropriate use of the stack effect) ensures improved air quality within the house, while minimising heatloss. You can still have a well-sealed house which has breathable (vapor-permeable) walls.


Edited by Jon Senior (11/25/12 12:48 PM)
Edit Reason: Reply to another post
_________________________
Jon

Contemporary Norman longhouse in Normandy

Top
#29869 - 12/02/12 06:46 PM Re: Infill and Half Timbering [Re: Jon Senior]
Hylandwoodcraft Offline
Member

Registered: 03/23/11
Posts: 141
Loc: Western NY
Hi everyone,
It looks like the project is going to go forward. We'll be using W. Oak for the frame. I'm going to order a few different gasket materials and see what I think. I'll keep everyone updated as it progresses. Thanks for all the feedback....

Top
Page 1 of 5 1 2 3 4 5 >

Moderator:  Jim Rogers, mdfinc 
Newest Members
bls2017, ReverendErn, laurenjv, VanMJones, weldoak
4725 Registered Users