Will almost green logs be good for repairs in scribed log walls?

[TW]

The loghouse that I am working on in weekends will probably reach ceiling height quite soon and the owner will put the upper part together himself so I am thinking about next project for another owner that will start in mid May.

The next project is a old house that has been taken down last summer and now we will put it back together. The first log is rotten and will have to be replaced on two outer walls and a partition wall. The construction is 6" thick hewn and scribed logs with dovetailed corners.
We have not been able to find any old replacement logs that are big enough so the owner will cut down some spruce and get it sawn to 6" thickness. There will be about 2 months for drying. Does the shrinkage matter?

[slowzuki]

Well, it does matter if your door frames etc can't accomodate more shinkage.  Likely its should be sawn a bit thick so the desired thickness will occur when it dries.  There are shrinkage rates available for most species.  Also if only one side of the building is being repaired, the building may sit slightly funny until is finishes drying.

[TW]

I never thought of that solution.
It would maybe be possible to cut the long groove in the next log a bit too shallow. That would give some excess height to the wall. Thanks

6" thickness means that the finished wall is 6" thick. The logs are scribe fitted to each other as with round logs. Door frames is not a problem.

[Don P]

I';m not sure it would be the way to go in this one since it is down and being reassembled. On 2 jobs where the house was standing, and as usual was built too close to the ground, I've removed the bottom rotten course and replaced it with masonry. In one case stone and the other a stucco over poured concrete.

[TW]

Don P
We cannot do like that because the masonsy wall would cause moist and insulation problems in our climate. The lowest (rotten) log protrudes above the floor level inside.

In fact we will add one more log under all walls to give room for proper insulation in the floor. Theese extra logs will shrink evenly under all walls thereby causing no problem.

It is the replacement logs that is the problem because they will not shrink evenly on all walls.


Logbuilding is interresting. The brain has to work all the time. Sometimes your advice from this forum does not fit in our climate and with our technique but still it is a great help to see how others solve quite similar problems.

[barbender]

TW- I don't think the number of logs you are replacing will make that much of an issue with settling.  I think on green softwoods the shrinkage rate is usually around 6%, so about 1/2 to 3/4 of an inch on a foot of wood.  If the owner has these logs sawn to 6" thick and then lets them dry for 2 months I would think they would dry a fairly substantial amount, especially if it is spruce or some other fast drying species.  So if you were replacing one 10" log you could leave it a little thick, however much you figure it will shrink.

[TW]

barbender
I hope you are right. Now when you and slowzuki agree on the principle then I have to believe in it.

Thanks for the input

[TexasTimbers]

There is a type of log construction used which uses rebar. You drill 3/4" holes along the axis of the bottom log and the next higher course every 18 - 24" (can't remember), pound in the 3/4" rebar and continue the process. The green logs shrink equally around the rebar, getting tighter around it also, so that the beauty oif it is that while the diameter of the log shrinks, it's position in the wall, the centerline, stays where it is. Thus, you don't have the problem of the sagging wall crushing your door frames etc. and you top plate stays put over the coming months and years.
There's a little more to it, and I have a notebook full of notes on it, but there have been alot of log homes built this way.
I'm not a TV hound but there was a series called Northern Exposure back in the 80s or o90's, the "log cabin (more like a log palace)" used in that series was constructed this way. It is a monster of a log home and has one of the largest ridge poles in North America. The biggest one I know of is in a resturaunt in Orgeon that has 5000 BF of lumber in it alone.
Anyway, it's where my wife and I took our log construction classes back in December of 04.
I don't see why you couldn't use this on just the bottom two courses. You wouldn't need to after that since shrinkage is not a factor.

For what it's worth Here's the Website. Lots of pictures of log home that have been built this way.

[TW]

Maybe.

It sounds too good to be true. I must think about it and discuss with somebody else. I have been told by the old men to never use any iron in a log wall, except nails and such smaller tings. I need evaluation time.

[barbender]

Kevjay-the problem with the method you describe is that in full scribe construction, the logs need to be able to settle together or you will get large gaps over time.  The logs are still going to shrink, it's just that if they can't move freely yhey will shrink apart.  TW- I am planning on using wooden dowels in my log walls for lateral stability, I have read about log home restorers taking old logs out and if they have rebar in them they are rotten around the rebar that was in them, the metal gets condensation on it constantly and causes the wood to rot.  Some log builders now will put a length of pvc tubing in a log to run through bolts in to alleviate this problem.  Settling in a log home is just something you work with, it's really not that big a deal once you get it in your head that everything is going to move.  And I guarantee that ANY log home built with horizontal wood is going to settle no matter what way you do it.

[barbender]

By the way TW those old men most always know what they're talking about. I'd get all the advice from them that I could.

[TexasTimbers]

Barbender it isn't the "problem" it is the solution to wall settling. Maybe it won't work with scribe i don't know. You do have to rechink after a year. I too subscribe to the Old Men philosophy but in this case it is a different technology and quite proven.
I didn't do it only because a log cabin in Texas just seemed like overkill and besides we discovered TFing right after the class and decided we liked that much more.

I just want to remind y'all I AM NOT any kind of log home expert or even close. I'm just sharing what I learned and what I have seen. Take it with a grain of salt.

[TW]

barbender
I am not worried about settling as a phenomena because the Scandinavian method of logbuilding allows for settling. I am just worried about the uneven settling that is cused by some new logs in a 100 years old loghouse. You came up with a logical explanation for avoiding iron pegs. It may be a different matter for kevjay down south where they do not have as big temperature differences in the walls.

The "old men knows" philosophy is not very appliable for me because those who have been professional logbuilders are dead by now. My grandfather was one of the last professionals and he died in the seventies, before I was born.   
Very few loghouses have been built after 1950 so the old men of today do not have much experience of logbuilding. Still I ask them because they know at least something and may give some lead.
It feels a bit like reinventing the wheel.

[UNCLEBUCK]

Just my 2 cents but some of the worst scandinavian scribed cabins I have ever seen were built by old timers using old fashioned techniques and outdated round notches . Scribing they did but their allowances and techniques are pre-historic . Those canadians like the Mackie School are really up to date and always top shelf for perfecting round log methods. Now timber framing I think is about as specialized as it gets and the fine craftsmanship shows in the young and old professionals . The old round log crafters from years and years ago I think were just trying to get out of the weather as fast as they could !

[HARLEYRIDER]

Those canadians like the Mackie School are really up to date and always top shelf for perfecting round log methods.

...Mackie,  and Pat Wolfe's log building school