Wednesday, April 9, 2008

Log Homes and Insulation Values

The insulation values of log homes has been a subject of great debate among building professionals for decades. And indeed, it is a topic that will be debated for quite some time. But perhaps the best evaluation of the insulation properties of a log home must be understood through the properties of wood as an insulator as well as a conductor of thermal heat and cooling.

Perhaps one of the most classic examples is having a piece of ice covered in sawdust for an extended period of time. You would find that that although the ambient temperature may be around room temperature or higher, the ice completely surrounded by sawdust may last several weeks or months before melting. We witness this effect every spring in our log yard and still find pieces of ice and snow well into June when we remove some of our peelings and shavings for co-generation fuel.
Although wood has a generic R-value of about 1.5 per inch of thickness, consideration must be given to the thermal mass properties of the log work. For instance, once a heat source has been eliminated from a house during cold weather conditions, a log home takes much longer to cool down than one consisting of drywall. Conversely, a log home takes much longer to heat up in the summer therefore reducing the consumption of energy used for air conditioning. Due to the stability of the temperature of wood during heating and cooling periods, less energy is used to heat and cool log homes due to the thermal mass of the logs themselves.

There are several technical study reports available that fully elaborate on the subject of energy efficiency of log homes and all conclude that log homes are more energy efficient than conventionally constructed homes.
To read more download "The Energy Performance of Log Homes" report prepared by the Technical Committee of the Log Home Council, Building Systems Councils and the National Association of Home Builders

By Walter Bramsleven
General Manager/Director of Sitka Log Homes
President of The BC Log & Timber Building Industry Association

3 comments:

Bearfort said...

Excellent information and list of resources.

One thing to keep in mind is that once must make sure that the seal between logs is sound - for those that employ chinking this means inspecting your chinking at least twice a year whether you use synthetic or mortar based chinking.

For homes that use chinking - this is the greatest barrier for drafts. However, since heat rises one must take extra care as to proper insulation in the roof and that there is a tight seal between the walls and roof.

Generally log homes have a greater insulation value than traditional stick built homes.

Great stuff guys. Your log homes are beautiful indeed.

I help people with the restoration of log homes -- I dont sell anything -- just provide information. http://www.bearfortlodge.com

Insulation or R-value of logs has always been one of the first questions people ask about.

Sitka Log Homes said...

Hi Bearfort! I'm sorry to be so long in replying...just getting used to blogging.

Thanks for the helpful comments. You have lots have handy info on your site for all log home enthusiasts.

Great to hear from you!

Ken Biz said...

The material in spray foam insulation is additionally non-toxic, but it is liquid based plus consists  of a polymer and a foaming agent.