Insulation rating per inch of thickness for pine logs

[Sully]

I am in the process of selling my home in IL, and relocating in N.E. Oklahoma near Grand Lake. I am planning to build a small Log Cabin there to enjoy the rest of my days in. I am trying to decide on the thickness I want to have my logs cut. I am using a local saw mill to supply my material. Any imformation will be greatly appriciated.

Ken "Sully" Sullivan

[Klapton]

What thickness to cut the logs? If you cut into the logs, they aren't logs anymore. Now they are big timbers or boards. If you want your cabin to last the rest of your days, DON'T USE MILLED LOGS!!! Use whole, hand-peeled logs in the tight-pinned butt and pass method (what they teach here at LHBA). Any time you cut into the grain of a log, you make it succeptible to water infiltration and rot. And if you stack them flat against flat, like most chinkless kit builders do, capillary action will draw water into the cracks, promoting rot.

I've seen varied calculations for the R-Value of logs. 1.25 per inch is one quote I've seen a lot.

Most folks try to get at least 12" logs, but it can be done as small as 10". But generally speaking, bigger is better. Both for R-Value and thermal mass, and also because it takes fewer logs to get the height you want, and less chinking to do between them.

[adubar]

Welcome Sully,

When speaking about energy efficiency in log home building, "Thermal Mass" is what is of concern, more so than an R value. Log homes are different in this repsect from stick frame homes.

I'm not too sure about how you are planning on getting your lumber "cut," but in the LHBA's preferred building methods, the only cuts you need worry about for sourcing logs is the end cuts (=length of log).

I would not suggest using milled "logs" to build your cabin, unless you have a full-proof design to mitigate moisture/water and understand the maintenance required for the longevity of the structure.

If you plan to build the cabin yourself, I'd strongly encourage you to take the LHBA's class.

Best of luck.

-A

[Yuhjn]

You really dont need to worry about the insulating properties of your log walls, they will be MUCH higher than any stick built home.

What you DO need to worry about is the insulating properties of your roof. That's where 80% (or more) of your heat will be lost. Second to that is your floor. After that are your windows and their frames.

Cutting into the logs is bad, either it's coping the corners for saddle notching, or scribing down the length of the logs to get a better "fit", or planing the whole log flat on both (or all 4) sides. None of these techniques is advisable nor necessary. There are basically two reasons people would do such a thing. The first is ignorance, and the second is because they are trying to make money selling log home kits by manufacturing them in a warehouse and then shipping them on a truck to the build site where some 3rd party contractor assembles them.

It's really awesome that you are interested in log homes, they are both practical and beautiful when built correctly.

The best advice anyone on this site is going to be able to give you regarding your log home is to "take the class" and become a member of the LHBA. That will answer 90% of your questions. After that you'll have lifetime support from the LHBA staff and of course access to the members forums.

Good luck!