In building my log house, the plan is:
Using SYP from my own woodlot, I'll be milling 3 sides to 8"x8"x8" on my Logosol CSM, then removing the remaining outer side bark with a drawknife. Will be using butt and pass construction and connecting the logs approximately every 3 feet with rebar. After the logs dry and shrink on the rebar, will fill the flat gaps both inside and outside with strips of closed cell foam slit from lengths of pipe insulation. Nothing else will be added to the wall , neither on the outside nor the inside. Do not plan on chinking (other than the pipe insulation) because there will be a perimeter porch that will protect from rain and the closed cell foam will fit tight enough to keep out the bugs.
Question 1: Has anyone done anything similar to this and how did it work out ?
Question 2: Will this method possibly cause any moisture to be trapped between the inner and outer foam strips ?
Question 3: If yes to question 2, what would be a better substance to use for the insulation between the logs ?
Thanks for your answers,
Jim
We don't do a lot of logs here but some, and have been around others.
I think a backer rod such as used in tilt up concrete construction under Sikaflex would be easier.
http://www.google.com/products?q=closed++cell+foam+backer+rod
I wouldn't worry about the moisture - it will leave through the logs. You won't possibly seal it all that tight.
You could put standard fiberglass insulation cut into strips - I have seen it in scribed log homes before.
I have built in a similar manner and found placing one or two layers of fiberglass sill sealer between each course of logs. Its cheap and pretty effective as draft prevention. If external chinking was needed later I used silicone caulking and it seemed to stay flexible and sealed.
rwanders,
Its good to see another log home guy here! Since you are going to the trouble of milling the logs on three sides, it seems a shame that you are planning on letting them settle/shrink away from one another. Typically milled logs wouldn't require chinking as the smooth surfaces would be sufficiently flush to seal without it.
If you are waiting for gaps to appear before you act, and restrict your remedy to stuffing foam into cracks as they appear, you are asking for a lot of heartache. Cracks that are too small to stuff foam into will still be plenty big to allow cold air (and bugs) to infiltrate.
You should be able to eliminate these problems ahead of time by laying some insulation between each log as you lay them. Also, if you are concerned with the logs hanging up on the rebar, causing gaps to appear as the logs dry and shrink, you can use threaded rods that allow you to keep the logs tight against one another would keep your walls nice and tight. Some I've seen actually incorporate springs so the logs are always being pulled together. As the logs settle, you just tighten the nuts.
-- Pritch
rwanders, I would probably go with a "perma-chink" chinking. Here is a site that might help and has other items regarding your log home. The logs that I used were old and the joints some of which were very large so I used mortar chink and inserted a piece of insulation board between the logs before the lathe and mortar.
Although the price is a little steep I have heard good comments about is flexibility and adhesion. Just too much for my application.
http://www.permachink.com/
Jim, I have to agree with what Don P told you on timber framing.
http://www.forestryforum.com/board/index.php/topic,32293.0.html
I realize that he doesn't always say what we want to hear, but he sure is right most of the time.