log building style question

[MTB]

Has there been any discussions on this forum about combining the structural benefits of the re-bar in the butt and pass method with the fit and look of a the full scribe method. I know there are advantages to the butt and pass method, but I'm having a hard time understanding why the same benefits of the re-bar in butt and pass can't be used in full scribe.
Thanks,
Bob

[StressMan79]

logs shrink. if they were rebar-ed togehter, a full scribe home would open up, and with no chinking to stop the wind, you'd have many 1/8th inch gaps all around your house letting the cold (or hot) in.

[rreidnauer]

I don't believe it was ever discussed, but your first problem would be, as the logs shrink to their centers, supported by the rebar, you would end up with gaps between logs. This could be minimized if the logs were very well seasoned to lowest water content possible. Even then, there are additional disadvantages to scribed logs, other than settling.

[MTB]

Doesn't the same shrinkage issue apply in a butt and pass home aside from the chinking? I was still thinking about chinking the full scribed logs but it seems that it would substantially minimize the amount of chinking material.
Bob

[MTB]

Rod,
The detail in you model is amazing. How big is the model? What size dowels did you use?
Bob

[StressMan79]

the home is supported by the rebar... so the chinking compensates for the change in dimensions of the logs. Putting chinking in a scribed home is like putting a bandaid over a gaping wound... and would require twice as much work. You'd still need to chink, and chinking is cheap, it is the time that would not be significanlty reduced using this method, plus you'd need more trees and the resale value would be hurt since the full scribe chinkless look that some want would be gone.

all in all a good question but a bad idea.

[MTB]

While explaining the benefits of a log house to my family the "why can't we use what's best in both methods" question arose. I also have a log building school 30 min from my house and to be honest I would like the hands on exposure. I'm a "why guy" and am just trying to understand the technical reasons why no to combine methods.

[rocklock]

I don't know if you folks have ever tried to full scribe a log or even an section of a log. It is tough. I can't do it. I have one notch in my entire home and it is ugly. Period. OBTW, it is chinked over and you can't find it.
I can drill a hole and pound the crap out of rebar driving it into the lower log. So my decision was made, a tight-pinned butt and pass log home. So what happens when the logs shrink? The insulation that is stuffed between the logs expands to fill any gaps. Then if needed the chinking can be touched up. I might note that we have a great example were the chinking has been in place for approximately 30 years and even though there are small gaps (between the logs and the chinking) the insulation has expanded and no or very little infiltration has occurred.
My big problem with full scribe homes are many. I believe steel rods and necessary. You cant just stack a bunch of logs and let gravity hold them together. I believe they require adjustment as the log wall shrinks. The shrinkage can be as much as 10% I'm told. 10% of a 18 foot wall can be as much as 20 inches. Figure that one out! Then you need to LOWER YOU ROOF. I don't know about you but I want my roof to stay in one place and not move around a bunch. I don't know why, may be I just want to stay dry and warm, or some thing. Lower my roof...no way. Then if you error on the height of a door, when you roof gets lowered it will crush the casing and make the door very sticky until it gets fixed. (Note: We went to a D-log home where this happened after about 5 years after the end of construction. He lowered his roof to fix the infiltration and crushed a door.) And I don't want to even think about plumbing and electrical stuff that needs to have weird stuff happened to it to make it work.
About green logs. I love it when some one says that they age or cure there house logs. They get really excited when they pronounce that they build with standing dead or other cured logs. The real truth is that the rule of thumb is that logs air cure about an inch a year. So if you use really big logs it can take 10 years for the log to stop shrinking. And even after they stop shrinking they change size according to the season. So logs move and green logs move a lot. The more you can do to mitigate this the better. Even stick built home shrink some.
So there you have it. You can touch up your chinking with a caulking gun (if you feel really anal) or lower your roof and all the other stuff that goes with it... Take your pick.
Hows that why guy...
see http://en.wikipedia.org/wiki/Log_home
So if you want to see what a slightly dyslexic a 66 year old man and his son can do check out my log home.

[StressMan79]

is a very good way to build a log home, but requires far more than 10 days to learn how to do it. The class you mention likely teaches a chainsaw scribe method that we usually call "canadian chinkless." This is not a good way to build, for many reasons, but first among them b/c you end up with a longitudinal sharp notch that is continually being forced apart. There are hybrid methods that aren't quite as bad, but not nearly as supierior to the "sweedish cope"

anyway, I don't know Ron Brodigan, he may be a great guy, and he may be a sheister. I suspect that he teaches a class that you can learn the fundamentals of a chainsaw-scribe method. I plan to stack all of my logs in 10 days or so. I suspect that there is no way to get a scribed house up that fast.

In short, scribed homes can be a very good home, you have to account for shrinkage/settling and you have to avoid the canadian chinkless method. You'll need more logs, since you lose ~1/5 of a log in each joint due to the joints/lack of chinking.

-Peter

[rreidnauer]

Driftwood and MTB,
Absolutely, you can take the best of both designs. No problem there. It's just a matter of selecting the correct features. Pinning a full scribe would definitely not be one of them. I'm hesitant to describe some of the correct choices for fear of triggering this thread to be moved to the member's section by revealing too sensitive information, so I'll just leave it at I recommend you take the class. For all I know, the full scribe class may teach many of those favorable features. One thing I'm certain of though. Full scribe is MUCH more work.

[rreidnauer]

Rod,
The detail in you model is amazing. How big is the model? What size dowels did you use?
Bob

It was a bit of a runaway train that wasn't suppose to get that detailed, but that's just how I am. There is no need to create such a detailed model.
The scale is 1:24, and represents an interior dimension of 35'x35', making the model approximately 27" long x 22" wide x 16" high. Most of the dowels are 1/2".

[MTB]

Dave,
I really appreciate the information. I completely agree that a pinned home will not settle as much as one the is not pinned. That's why I'm not considering building a unpinned full scribed home. I believe the foam between the logs is the answer I was for "that makes sense", but my question still stands though with a few additional caveats. Is there a technical reason why a full scribed home that was also pinned, with foam between the logs and chinked ( I like the look of chinking) would not have all the same stability characteristics of a pinned and chinked butt and pass home?
Please don't take my questions as an attack on the butt and pass method of building. I not intending to argue or debate with those who have much more experience in building than I do. I'm just trying to understand so I can proceed with a plan that makes the most sense for my family.
Bob

[staff]

The question in the original post has been answered. It would not be advisable to use rebar in a Scandinavian Chinkless style log home.
It would be more standard to through bolt the logs, and then use a sping loaded nut.
http://www.loghomebuilders.org/files/images/spring-loaded-nut.preview.JPG