Cob as log cabin chinking

Hi
i am working on a small log cabin right now. its made of spruce logs and i am wondering if people think that chinking with cob would be a good idea, or if i should use the regular mortar stuff. the only thing i am worried about with the cob is if the cob, being essentially soil, could rot the logs when it gets wet. i know there are timberframe houses with cob i think touching the timbers and they dont seem to rot...  but im not sure. i just wanted to double check to see what people think.
also cob is sand and clay, is it possible the clay has a preserving affect on the wood, even with sand mixed in?
thanks very much for any responses. i really like my cabin, so i just wanted to check to make sure it doesnt ruin it.
Christoph

Howdy;

Not a cob expert, have only worked on one cob build, in a southwest USA environment(dry, arid) but the interior area floor is covered with like linseed oil mixture, after its dry. Makes a hard waterproof surface?  

cool yeah i heard thats good on cob floors.

christoph Berger wrote:the only thing i am worried about with the cob is if the cob, being essentially soil, could rot the logs when it gets wet. i know there are timberframe houses with cob i think touching the timbers and they dont seem to rot...  but im not sure. i just wanted to double check to see what people think.

The logs themselves will rot if they stay wet long enough.  The key with any wood structure to keep it from rotting is to keep it dry. With a roof and eaves, generally the walls will be dry enough just from the airflow.  In some spots in extremely wet climates, perhaps the cabin would rot over time from being too moist.  But this can be countered as well by having a fire to dry the cabin from inside.

You don't necessarily want to oil the exterior of cob walls because it could trap moisture inside and prevent the structure from "breathing".  I'm not an expert on when to oil or not, but it's something to think about and research.

Thanks Philip!
I have a roof with decent overhang. I know it will still get some rain when it's windy, but not too bad.