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#29811 - 11/21/12 07:21 PM Re: Infill and Half Timbering * [Re: timberwrestler]
TIMBEAL Offline
Member

Registered: 12/10/07
Posts: 1875
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.

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#29812 - 11/21/12 07:41 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.

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#29814 - 11/21/12 08:33 PM Re: Infill and Half Timbering [Re: Hylandwoodcraft]
bmike Offline
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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

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#29816 - 11/22/12 01:25 AM Re: Infill and Half Timbering [Re: bmike]
D Wagstaff Offline
Member

Registered: 02/17/12
Posts: 250
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

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#29817 - 11/22/12 10:13 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.

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#29818 - 11/22/12 11:01 AM 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.

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#29819 - 11/22/12 03:17 PM Re: Infill and Half Timbering [Re: bmike]
D Wagstaff Offline
Member

Registered: 02/17/12
Posts: 250
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

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#29824 - 11/23/12 07:15 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.

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

Registered: 12/10/07
Posts: 1875
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.

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

Registered: 05/04/11
Posts: 114
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

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