Dug;

the geographical locations means a lot in determining if you have the right solution , where is the home located?

Tell us more about the roof structure of the log home.
Construction and insulation details will help us, as well as location.

Kansas City area.

Roof is SIP.

Full poured basement.

The logs are 8 inch round by Neville. During construction a foam strip was layed between each log. While chinking was not required, the owner has since chinked the exterior, but this has not helped reduce energy costs.

To illustrate the costs, his home is 50% larger than mine. His heating costs during December 2009 were $700 with LP and wood supplement. Mine was $150 with electric, no wood supplement. (My home is ICF with Icynene sprayed on the underside of the roof deck.)

I suggest you start with an energy audit. A blower door test and thermogrpahy will tell you if you have problems with the shell. You need to know where the heat is going before you solve the problem. If the wood heat a fireplace, wood stove or pellet burner? What about water heaters. Ho many people live in the house and what is the hot water useage?

Are you talking about an LP delivery for $700 but would last for more than a month?

Wood has a very low R value , around 1 per inch. Thus an 8 inch log makes the wall about an R8. Logs shrink over time. You could have some major air leaks around wndows, between logs and at the roof connection, etc.

What does the house have for windows?

I would spray the outside like you are saying if that is what the customer wants... (to lose the log look)

Why did he buy log?????

If it were me and made a big mistake like that... I would just sell the problem and start over... kinda crazy to spend big bucks to make a log home look like a rock home isn't it?

aj

by the by... I have built 10 Lincoln Logs... and they are not as insulated as an ICF or a passive house not even close to standard stick and fiberglass if not rechinked super well and blower door tested.

If it's foamed from the exterior, termite inspection & remediation may become impossible. For ant & termite control it might be better to use high-borate wet-blown cellulose instead of Icynene.

But putting the logs 100% inside the thermal & pressure boundary like will keep the wood from taking on moisture, and it'll stay dryer, with caveats: Stone is a moisture-reservoir, and vapor-drives from sun on dew or rain-wetted stone is high. Without some exterior vapor retardency the studs are at some risk. The cavity between the stone & sheathing will help, but using something more vapor-retardent than just half-pound foam might be a good idea. Going with 2x3 studs with an Icynene or cellulose cavity fill and sheathing the studwall with 1-1.5" of XPS (semi-impermeable) under the felt/housewrap would keep the studs on the protected side of the summertime vapor drive, and at least partially inside the thermal boundary to keep them warm enough to limit accumulating moisture from interior air during the winter. Since neither the sheathing nor the studwall is structural, you don't really need to build it to a structural spec, and foam sheathing will provide a thermal break over the studs.

IIRC logs undergo seasonal dimensional changes, and keeping a perfect air seal will not be easy. Blower door testing and paying close attention to air-sealing the ceiling to reduce stack-effect infiltration drives will probably be a critical first-step. Using half-pound foam for air sealing the edges of that interface will be more flexible than most other methods.

Sounds a bit like the old Irish joke where the answer is I would not start from here.

I would be inclined to keep the outside as is as the waterproof envelope and build my insulation inside, I would be more inclined to move.